[jbpm-commits] JBoss JBPM SVN: r4749 - in jbpm4/trunk: modules/devguide/src/main/docbook/en and 21 other directories.

Author: tom.baeyens(a)jboss.com Date: 2009-05-06 10:03:44 -0400 (Wed, 06 May 2009) New Revision: 4749 Added: jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch03-Configuration.xml jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch04-Architecture.xml jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch05-ImplementingBasicActivities.xml jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch06-ProcessAnatomy.xml jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch07-ImplementingAdvancedActivities.xml jbpm4/trunk/modules/distro/src/main/files/jboss/config.jboss4/deploy/jbpm/jbpm-service.sar/META-INF/ jbpm4/trunk/modules/distro/src/main/files/jboss/config.jboss4/deploy/jbpm/jbpm-service.sar/META-INF/jboss-service.xml Removed: jbpm4/trunk/modules/api/src/main/java/org/jbpm/api/ProcessService.java jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch03-Architecture.xml jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch04-ImplementingBasicActivities.xml jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch05-ProcessAnatomy.xml jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch06-ImplementingAdvancedActivities.xml jbpm4/trunk/modules/distro/src/main/deployer/ jbpm4/trunk/modules/distro/src/main/resources/ Modified: jbpm4/trunk/modules/devguide/src/main/docbook/en/master.xml jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch01-Introduction.xml jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch02-ProcessVirtualMachine.xml jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/chxx-ExecutionModes.xml jbpm4/trunk/modules/distro/src/main/files/jboss/config.common/deploy/jbpm/jbpm-service.sar/jbpm.cfg.xml jbpm4/trunk/modules/distro/src/main/files/jboss/jbpm.cfg.integration.tests/jbpm.cfg.xml jbpm4/trunk/modules/distro/src/main/files/jboss/jbpm.cfg.remote.client/jbpm.cfg.xml jbpm4/trunk/modules/enterprise/src/test/java/org/jbpm/enterprise/internal/ejb/TimerTest.java jbpm4/trunk/modules/enterprise/src/test/java/org/jbpm/test/deployer/DeployerTestServlet.java jbpm4/trunk/modules/examples/src/test/resources/jbpm.cfg.xml jbpm4/trunk/modules/jpdl/src/main/resources/jbpm.jpdl.cfg.xml jbpm4/trunk/modules/jpdl/src/test/resources/jbpm.cfg.xml jbpm4/trunk/modules/pvm/src/main/java/org/jbpm/pvm/internal/env/JbpmConfigurationParser.java jbpm4/trunk/modules/pvm/src/main/java/org/jbpm/pvm/internal/wire/binding/VersionTimestampPolicy.java jbpm4/trunk/modules/pvm/src/main/resources/jbpm.default.cfg.xml jbpm4/trunk/modules/pvm/src/main/resources/jbpm.identity.cfg.xml jbpm4/trunk/modules/pvm/src/main/resources/jbpm.jbossremote.cfg.xml jbpm4/trunk/modules/pvm/src/main/resources/jbpm.jobexecutor.cfg.xml jbpm4/trunk/modules/pvm/src/main/resources/jbpm.tx.hibernate.cfg.xml jbpm4/trunk/modules/pvm/src/main/resources/jbpm.tx.jta.cfg.xml jbpm4/trunk/modules/pvm/src/test/resources/jbpm.cfg.xml jbpm4/trunk/modules/pvm/src/test/resources/org/jbpm/pvm/api/db/svc/environment.cfg.xml jbpm4/trunk/modules/pvm/src/test/resources/org/jbpm/pvm/api/timer/environment.cfg.xml jbpm4/trunk/modules/test-db/src/test/resources/jbpm.cfg.xml jbpm4/trunk/modules/test-load/src/test/resources/jbpm.cfg.xml jbpm4/trunk/qa/hudson-jbpm4-jboss.sh Log: cleanup and developer documentation Deleted: jbpm4/trunk/modules/api/src/main/java/org/jbpm/api/ProcessService.java =================================================================== --- jbpm4/trunk/modules/api/src/main/java/org/jbpm/api/ProcessService.java 2009-05-06 12:55:13 UTC (rev 4748) +++ jbpm4/trunk/modules/api/src/main/java/org/jbpm/api/ProcessService.java 2009-05-06 14:03:44 UTC (rev 4749) @@ -1,59 +0,0 @@ -/* - * JBoss, Home of Professional Open Source - * Copyright 2005, JBoss Inc., and individual contributors as indicated - * by the @authors tag. See the copyright.txt in the distribution for a - * full listing of individual contributors. - * - * This is free software; you can redistribute it and/or modify it - * under the terms of the GNU Lesser General Public License as - * published by the Free Software Foundation; either version 2.1 of - * the License, or (at your option) any later version. - * - * This software is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * Lesser General Public License for more details. - * - * You should have received a copy of the GNU Lesser General Public - * License along with this software; if not, write to the Free - * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA - * 02110-1301 USA, or see the FSF site: http://www.fsf.org. - */ -package org.jbpm.api; - -import java.util.List; - - -/** a process definition repository. - * - * @author Tom Baeyens - */ -public interface ProcessService { - - /** start a deployment */ - Deployment createDeployment(); - - /** all deployed process definition keys. */ - List<String> findProcessDefinitionKeys(); - - /** all versions of the given process. - * @return the process definitions in descending version order. So you get the - * highest version number as the first. */ - List<ProcessDefinition> findProcessDefinitionsByKey(String processDefinitionKey); - - /** latest version of the processDefinition with the given key. */ - ProcessDefinition findLatestProcessDefinitionByKey(String processDefinitionKey); - - /** specific version of a named processDefinition. */ - ProcessDefinition findProcessDefinitionById(String processDefinitionId); - - /** search for process definitions */ - ProcessDefinitionQuery createProcessDefinitionQuery(); - - /** deletes process definition if there are no existing executions. - * @throws JbpmException if there are existing executions or history. */ - void deleteProcessDefinition(String processDefinitionId); - - /** deletes process definition, the existing executions and the history. */ - void deleteProcessDefinitionCascade(String processDefinitionId); -} Modified: jbpm4/trunk/modules/devguide/src/main/docbook/en/master.xml =================================================================== --- jbpm4/trunk/modules/devguide/src/main/docbook/en/master.xml 2009-05-06 12:55:13 UTC (rev 4748) +++ jbpm4/trunk/modules/devguide/src/main/docbook/en/master.xml 2009-05-06 14:03:44 UTC (rev 4749) @@ -3,10 +3,11 @@ <!DOCTYPE book [ <!ENTITY ch01-Introduction SYSTEM "modules/ch01-Introduction.xml"> <!ENTITY ch02-ProcessVirtualMachine SYSTEM "modules/ch02-ProcessVirtualMachine.xml"> - <!ENTITY ch03-Architecture SYSTEM "modules/ch03-Architecture.xml"> - <!ENTITY ch04-ImplementingBasicActivities SYSTEM "modules/ch04-ImplementingBasicActivities.xml"> - <!ENTITY ch05-ProcessAnatomy SYSTEM "modules/ch05-ProcessAnatomy.xml"> - <!ENTITY ch06-ImplementingAdvancedActivities SYSTEM "modules/ch06-ImplementingAdvancedActivities.xml"> + <!ENTITY ch03-Configuration SYSTEM "modules/ch03-Configuration.xml"> + <!ENTITY ch04-Architecture SYSTEM "modules/ch04-Architecture.xml"> + <!ENTITY ch05-ImplementingBasicActivities SYSTEM "modules/ch05-ImplementingBasicActivities.xml"> + <!ENTITY ch06-ProcessAnatomy SYSTEM "modules/ch06-ProcessAnatomy.xml"> + <!ENTITY ch07-ImplementingAdvancedActivities SYSTEM "modules/ch07-ImplementingAdvancedActivities.xml"> <!ENTITY ch10-SoftwareLogging SYSTEM "modules/ch10-SoftwareLogging.xml"> <!ENTITY ch11-History SYSTEM "modules/ch11-History.xml"> ]> @@ -21,10 +22,11 @@ &ch01-Introduction; &ch02-ProcessVirtualMachine; - &ch03-Architecture; - &ch04-ImplementingBasicActivities; - &ch05-ProcessAnatomy; - &ch06-ImplementingAdvancedActivities; + &ch03-Configuration; + &ch04-Architecture; + &ch05-ImplementingBasicActivities; + &ch06-ProcessAnatomy; + &ch07-ImplementingAdvancedActivities; &ch10-SoftwareLogging; &ch11-History; Modified: jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch01-Introduction.xml =================================================================== --- jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch01-Introduction.xml 2009-05-06 12:55:13 UTC (rev 4748) +++ jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch01-Introduction.xml 2009-05-06 14:03:44 UTC (rev 4749) @@ -10,12 +10,13 @@ </section> <section> - <title>Sources</title> - <para>The source code for jBPM can be found here: + <title>Sources and WIKI</title> + <para>The source code for jBPM can be found in our <ulink url="http://subversion.tigris.org/">SVN</ulink> repository:</para> <ulink url="https://anonsvn.jboss.org/repos/jbpm/jbpm4/">https://an... - </para> <para>A description of how to build the sources is available in the wiki:</para> <ulink url="http://www.jboss.org/community/docs/DOC-12867">http://w... + <para>The jBPM WIKI is located here:</para> + <ulink url="http://www.jboss.org/community/docs/DOC-11184">http://w... </section> <section> Modified: jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch02-ProcessVirtualMachine.xml =================================================================== --- jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch02-ProcessVirtualMachine.xml 2009-05-06 12:55:13 UTC (rev 4748) +++ jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch02-ProcessVirtualMachine.xml 2009-05-06 14:03:44 UTC (rev 4749) @@ -26,10 +26,11 @@ </figure> <para>The Process Virtual Machine doesn't contain any such activity implementations. It only provides the - execution environment and an activity API to write <literal>Activity</literal> + execution environment and an activity API to write <literal>ActivityBehaviour</literal> implementations as Java components. Activities can also be wait states. This means that the activity control flow goes outside the process system. For example a human task - or invoking an service asynchronously. + or invoking an service asynchronously. While the execution is waiting, the runtime state + of that execution can be persisted in a DB. </para> <para>Many executions can be started for one process definition. An execution is a pointer that keeps track of the current activity. Deleted: jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch03-Architecture.xml =================================================================== --- jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch03-Architecture.xml 2009-05-06 12:55:13 UTC (rev 4748) +++ jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch03-Architecture.xml 2009-05-06 14:03:44 UTC (rev 4749) @@ -1,250 +0,0 @@ -<chapter id="architecture"> - <title>Architecture</title> - - <section id="apis"> - <title>APIs</title> - <para>The Process Virtual Machine has 4 integrated API's that together - offer a complete coverage of working with processes in the different execution modes. - Each of the APIs has a specific purpose that fits within the following overall - architecture. - </para> - <figure id="apis"> - <title>The 4 API's of the Process Virtual Machine</title> - <mediaobject><imageobject><imagedata align="center" fileref="images/apis.png"/></imageobject></mediaobject> - </figure> - <para>The services interfaces should be used from application code that wants to interact - with the Process Virtual Machine which runs in transactional persistent mode, backed by a - database. This is the most typical way how users interact with the PVM as a workflow engine. - </para> - <para>To execute processes without persistence, the client API can be used to work with process - and execution objects directly. The client API expose the methods of the core model objects. - </para> - <para>The activity API is used to implement the runtime behaviour of activities. So a activity - type is in fact a component with at the core an implementation of the <literal>Activity</literal> - interface. Activity implementations can control the flow of execution. - </para> - <para>The event listener API serves to write pieces of Java code that should be executed upon - process events. It's very similar to the activity API with that exception that event listeners - are not able to control the flow of execution. - </para> - </section> - - <section> - <title>Activity API</title> - <para>The activity API allows to implement the runtime activity behaviour in Java. - </para> - <programlisting>public interface Activity extends Serializable { - void execute(ActivityExecution execution) throws Exception; -}</programlisting> - <para>An activity is the behaviour of the activity to which it is associated. - The provided execution is the execution that arrives in the activity. - The interface <literal>ActivityExecution</literal> exposes special - methods to control the execution flow. - </para> - <programlisting>public interface ActivityExecution extends OpenExecution { - - void waitForSignal(); - void take(String transitionName); - void execute(String activityName); - - ... - -}</programlisting> - </section> - - <section> - <title>Event listener API</title> - <para>The event listener API allows for listeners to be developed in Java code - and that are invoked on specific process events like entering a activity or leaving - a activity. It is very similar to the activity API, but the difference is - that the propagation of the execution flow cannot be controlled. E.g. when an execution - is taking a transition, a listener to that event can be notified, but since the - transition is already being taking, the execution flow cannot be changed - by the event listeners. - </para> - <programlisting>public interface EventListener extends Serializable { - - void notify(EventListenerExecution execution) throws Exception; - -}</programlisting> - </section> - - <section> - <title>Client API</title> - <para>The client API was already introduced above in the object execution mode - and embedded execution mode. It's an interface that exposes the methods for - managing executions on the plain process definition and execution objects directly. - </para> - <para>At a minimal, the client API and the activity API are needed to create - some a process definition with activities and execute it. - </para> - </section> - - <section> - <title>Environment</title> - <para>In the persistent execution mode, the first purpose of the environment is - to enable processes to be executed in different transactional environments like - standard Java, enterprise Java, SEAM and Spring. - </para> - <para>The PVM code itself will only use transactional resources through self-defined - interfaces. For example, the PVM itself has interfaces for some methods on the hibernate - session, a async messaging session and a timer session. - </para> - <para>The environment allows to configure the actual implementations, lazy - initialization of the services on a request-basis and caching the service - objects for the duration of the transaction. - </para> - <para>An environment factory is static and one environment factory can serve - all the threads in an application. - </para> - <programlisting>EnvironmentFactory environmentFactory = new PvmEnvironmentFactory("environment.cfg.xml");</programlisting> - <para>Environment blocks can surround persistent process operations - like this: - </para> - <programlisting>Environment environment = environmentFactory.openEnvironment(); -try { - - ... inside the environment block... - -} finally { - environment.close(); -}</programlisting> - <para>The PVM itself will fetch all it's transactional resources and configurations - from the environment. It's recommended that <literal>Activity</literal> implementations - do the same. - </para> - </section> - - <section> - <title>Commands</title> - <para>Commands encapsulate operations that are to be executed within an environment - block. The main purpose for commands is to capture the logic of - </para> - <programlisting>public interface Command&lt;T&gt; extends Serializable { - - T execute(Environment environment) throws Exception; - -}</programlisting> - <para></para> - </section> - - <section> - <title>Services</title> - <para>There are three services: <literal>ProcessService</literal>, - <literal>ExecutionService</literal> and <literal>ManagementService</literal>. - In general, services are session facades that expose methods for persistent - usage of the PVM. The next fragments show the essential methods as example - to illustrate those services. - </para> - <para>The <literal>ProcessService</literal> manages the repository of - process definitions. - </para> - <programlisting>public interface ProcessService { - - ProcessDefinition deploy(Deployment deployment); - - ProcessDefinition findLatestProcessDefinition(String processDefinitionName); - - ... - -}</programlisting> - <para>The <literal>ExecutionService</literal> manages the runtime - executions.</para> - <programlisting>public interface ExecutionService { - - Execution startExecution(String processDefinitionId, String executionKey); - - Execution signalExecution(String executionId, String signalName); - - ... - -}</programlisting> - <para>The <literal>ManagementService</literal> groups all management operations - that are needed to keep the system up and running. - </para> - <programlisting>public interface ManagementService { - - List&lt;Job&gt; getJobsWithException(int firstResult, int maxResults); - - void executeJob(String jobId); - - ... - -}</programlisting> - <para>The implementation of all these methods is encapsulated in - <literal>Command</literal>s. And the three services all delegate the - execution of the commands to a <literal>CommandService</literal>: - </para> - <programlisting>public interface CommandService { - - &lt;T&gt; T execute(Command&lt;T&gt; command); - -}</programlisting> - <para>The <literal>CommandService</literal> is configured in the - environment. A chain of CommandServices can act as interceptors - around a command. This is the core mechanism on how persistence and - transactional support can be offered in a variety of environments. - </para> - <para>From the default configuration which is included in full above, - here is the section that configures the services - </para> - <programlisting>&lt;jbpm-configuration xmlns=&quot;http://jbpm.org/xsd/cfg&quot;&gt; - - &lt;process-engine&gt; - - &lt;process-service /&gt; - &lt;execution-service /&gt; - &lt;management-service /&gt; - - &lt;command-service&gt; - &lt;retry-interceptor /&gt; - &lt;environment-interceptor /&gt; - &lt;standard-transaction-interceptor /&gt; - &lt;/command-service&gt; - - ... - </programlisting> - <para>The three services <literal>process-service</literal>, <literal>execution-service</literal> - and <literal>management-service</literal> will look up the configured - <literal>command-service</literal> by type. The <literal>command-service</literal> - tag corresponds to the default command service that essentially does nothing else - then just execute the command providing it the current environment. - </para> - <para>The configured <literal>command-service</literal> results into the following - a chain of three interceptors followed by the default command executor. - </para> - <figure id="interceptors"> - <title>The CommandService interceptors</title> - <mediaobject><imageobject><imagedata align="center" fileref="images/interceptors.png"/></imageobject></mediaobject> - </figure> - <para>The retry interceptor is the first in the chain and that one that will be exposed as the - <literal>CommandService.class</literal> from the environment. So the retry interceptor - will be given to the respective services <literal>process-service</literal>, <literal>execution-service</literal> - and <literal>management-service</literal>. - </para> - <para>The <literal>retry-interceptor</literal> will catch hibernate StaleObjectExceptions - (indicating optimistic locking failures) and retry to execute the command. - </para> - <para>The <literal>environment-interceptor</literal> will put an environment block - around the execution of the command. - </para> - <para>The <literal>standard-transaction-interceptor</literal> will initialize a - <literal>StandardTransaction</literal>. The hibernate session/transaction will be - enlisted as a resource with this standard transaction. - </para> - <para>Different configurations of this interceptor stack will also enable to - </para> - <itemizedlist> - <listitem>delegate execution to a local ejb command service so that an container - managed transaction is started. - </listitem> - <listitem>delegate to a remote ejb command service so that the command actually - gets executed on a different JVM. - </listitem> - <listitem>package the command as an asynchronous message so that the command gets - executed asynchronously in a different transaction. - </listitem> - </itemizedlist> - </section> - -</chapter> \ No newline at end of file Added: jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch03-Configuration.xml =================================================================== --- jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch03-Configuration.xml (rev 0) +++ jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch03-Configuration.xml 2009-05-06 14:03:44 UTC (rev 4749) @@ -0,0 +1,66 @@ +<chapter id="configuration"> + <title>Configuration</title> + + <para>The jbpm.jar contains a number of default configuration + files that can be imported by the user configuration file. + </para> + <para>This way, it's easy to include + or exclude features for users. And also the configuration details are kept in + the implementation so users that only import those configuration files + will not be affected when we release changes in those configuration files. + </para> + <para>Configuration files that can be imported by the user's <literal>jbpm.cfg.xml</literal>:</para> + <programlisting>jbpm.default.cfg.xml +jbpm.identity.cfg.xml +jbpm.jbossremote.cfg.xml +jbpm.jobexecutor.cfg.xml +jbpm.tx.hibernate.cfg.xml +jbpm.tx.jta.cfg.xml</programlisting> + <para><literal>jbpm.default.cfg.xml</literal>: Contains the default configurations + like the services, the hibernate configuration (configured from resource jbpm.hibernate.cfg.xml), + hibernate session factory, business calendar and so on. + </para> + <para>A typical configuration for standard java would look like this: + </para> + <programlisting>&lt;?xml version=&quot;1.0&quot; encoding=&quot;UTF-8&quot;?&gt; + +&lt;jbpm-configuration&gt; + + &lt;import resource=&quot;jbpm.default.cfg.xml&quot; /&gt; + &lt;import resource=&quot;jbpm.tx.hibernate.cfg.xml&quot; /&gt; + &lt;import resource=&quot;jbpm.jpdl.cfg.xml&quot; /&gt; + &lt;import resource=&quot;jbpm.identity.cfg.xml&quot; /&gt; + &lt;import resource=&quot;jbpm.jobexecutor.cfg.xml&quot; /&gt; + +&lt;/jbpm-configuration&gt;</programlisting> + <para>In a JTA environment, replace <literal>jbpm.tx.hibernate.cfg.xml</literal> + with <literal>jbpm.tx.jta.cfg.xml</literal> </para> + <para>To customize any of these configurations users can just replace + the import with the customized content in the <literal>jbpm.cfg.xml</literal>. + </para> + + <para>The jbpm.jar contains also following hibernate mapping configuration files:</para> + <programlisting>jbpm.execution.hbm.xml +jbpm.history.hbm.xml +jbpm.identity.hbm.xml +jbpm.repository.hbm.xml +jbpm.task.hbm.xml +jbpm.jpdl.hbm.xml</programlisting> + <para>These all map the java domain model objects to a relational database. + </para> + <para>Other various configuration files that are included in jbpm.jar:</para> + <programlisting>jbpm.task.lifecycle.xml +jbpm.variable.types.xml +jbpm.wire.bindings.xml +jbpm.jpdl.activities.xml +jbpm.jpdl.eventlisteners.xml</programlisting> + + <para>To get started on the parsing for the configuration files, see + </para> + <itemizedlist> + <listitem>class org.jbpm.pvm.internal.env.JbpmConfigurationParser</listitem> + <listitem>resource modules/pvm/src/main/resources/jbpm.wire.bindings.xml</listitem> + <listitem>package modules/pvm/src/main/java/org/jbpm/pvm/internal/wire/binding</listitem> + </itemizedlist> + +</chapter> \ No newline at end of file Property changes on: jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch03-Configuration.xml ___________________________________________________________________ Name: svn:mime-type + text/plain Copied: jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch04-Architecture.xml (from rev 4742, jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch03-Architecture.xml) =================================================================== --- jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch04-Architecture.xml (rev 0) +++ jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch04-Architecture.xml 2009-05-06 14:03:44 UTC (rev 4749) @@ -0,0 +1,260 @@ +<chapter id="architecture"> + <title>Architecture</title> + + <section id="apis"> + <title>APIs</title> + <para>The Process Virtual Machine has 4 integrated API's that together + offer a complete coverage of working with processes in the different execution modes. + Each of the APIs has a specific purpose that fits within the following overall + architecture. + </para> + <figure id="apis"> + <title>The 4 API's of the Process Virtual Machine</title> + <mediaobject><imageobject><imagedata align="center" fileref="images/apis.png"/></imageobject></mediaobject> + </figure> + <para>The services interfaces should be used from application code that wants to interact + with the Process Virtual Machine which runs in transactional persistent mode, backed by a + database. This is the most typical way how users interact with the PVM as a workflow engine. + </para> + <para>To execute processes without persistence, the client API can be used to work with process + and execution objects directly. The client API expose the methods of the core model objects. + </para> + <para>The activity API is used to implement the runtime behaviour of activities. So a activity + type is in fact a component with at the core an implementation of the <literal>ActivityBehaviour</literal> + interface. ActivityBehaviour implementations can control the flow of execution. + </para> + <para>The event listener API serves to write pieces of Java code that should be executed upon + process events. It's very similar to the activity API with that exception that event listeners + are not able to control the flow of execution. + </para> + </section> + + <section> + <title>Activity API</title> + <para>The activity API allows to implement the runtime activity behaviour in Java. + </para> + <programlisting>public interface ActivityBehaviour extends Serializable { + void execute(ActivityExecution execution) throws Exception; +}</programlisting> + <para>An activity is the behaviour of the activity to which it is associated. + The provided execution is the execution that arrives in the activity. + The interface <literal>ActivityExecution</literal> exposes special + methods to control the execution flow. + </para> + <programlisting>public interface ActivityExecution extends OpenExecution { + + void waitForSignal(); + void take(String transitionName); + void execute(String activityName); + + ... + +}</programlisting> + </section> + + <section> + <title>Event listener API</title> + <para>The event listener API allows for listeners to be developed in Java code + and that are invoked on specific process events like entering a activity or leaving + a activity. It is very similar to the activity API, but the difference is + that the propagation of the execution flow cannot be controlled. E.g. when an execution + is taking a transition, a listener to that event can be notified, but since the + transition is already being taking, the execution flow cannot be changed + by the event listeners. + </para> + <programlisting>public interface EventListener extends Serializable { + + void notify(EventListenerExecution execution) throws Exception; + +}</programlisting> + </section> + + <section> + <title>Client API</title> + <para>The client API is the interface that exposes the methods for + managing executions on the plain process definition and execution objects directly. + </para> + <para>At a minimal, the client API and the activity API are needed to create + some a process definition with activities and execute it. + </para> + </section> + + <section> + <title>Environment</title> + <para>In the persistent execution mode, the first purpose of the environment is + to enable processes to be executed in different transactional environments like + standard Java, enterprise Java, SEAM and Spring. + </para> + <para>The PVM code itself will only use transactional resources through self-defined + interfaces. For example, the PVM itself has interfaces for some methods on the hibernate + session, a async messaging session and a timer session. + </para> + <para>The environment allows to configure the actual implementations, lazy + initialization of the services on a request-basis and caching the service + objects for the duration of the transaction. + </para> + <para>An environment factory is static and one environment factory can serve + all the threads in an application. + </para> + <programlisting>EnvironmentFactory environmentFactory = new PvmEnvironmentFactory("environment.cfg.xml");</programlisting> + <para>Environment blocks can surround persistent process operations + like this: + </para> + <programlisting>Environment environment = environmentFactory.openEnvironment(); +try { + + ... inside the environment block... + +} finally { + environment.close(); +}</programlisting> + <para>The PVM itself will fetch all it's transactional resources and configurations + from the environment. It's recommended that <literal>Activity</literal> implementations + do the same. + </para> + <para>The <literal>org.jbpm.pvm.internal.cfg.JbpmConfiguration</literal> acts as Configuration, + ProcessEngine and EnvironmentFactory. + </para> + </section> + + <section> + <title>Commands</title> + <para>Commands encapsulate operations that are to be executed within an environment + block. The main purpose for commands is to capture the logic of + </para> + <programlisting>public interface Command&lt;T&gt; extends Serializable { + + T execute(Environment environment) throws Exception; + +}</programlisting> + <para></para> + </section> + + <section> + <title>Services</title> + <para>There are three main services: <literal>RepositoryService</literal>, + <literal>ExecutionService</literal> and <literal>ManagementService</literal>. + In general, services are session facades that expose methods for persistent + usage of the PVM. The next fragments show the essential methods as example + to illustrate those services. + </para> + <para>The <literal>RepositoryService</literal> manages the repository of + process definitions. + </para> + <programlisting>public interface RepositoryService { + + Deployment createDeployment(); + + ProcessDefinitionQuery createProcessDefinitionQuery(); + + ... + +}</programlisting> + <para>The <literal>ExecutionService</literal> manages the runtime + executions.</para> + <programlisting>public interface ExecutionService { + + ProcessInstance startProcessInstanceById(String processDefinitionId); + + ProcessInstance signalExecutionById(String executionId); + + ... + +}</programlisting> + <para>The <literal>ManagementService</literal> groups all management operations + that are needed to keep the system up and running. + </para> + <programlisting>public interface ManagementService { + + JobQuery createJobQuery(); + + void executeJob(long jobDbid); + + ... + +}</programlisting> + <para>The implementation of all these methods is encapsulated in + <literal>Command</literal>s. And the three services all delegate the + execution of the commands to a <literal>CommandService</literal>: + </para> + <programlisting>public interface CommandService { + + &lt;T&gt; T execute(Command&lt;T&gt; command); + +}</programlisting> + <para>The <literal>CommandService</literal> is configured in the + environment. A chain of CommandServices can act as interceptors + around a command. This is the core mechanism on how persistence and + transactional support can be offered in a variety of environments. + </para> + <para>The default configuration file <literal>jbpm.default.cfg.xml</literal> + includes following section that configures the services + </para> + <programlisting>&lt;jbpm-configuration&gt; + + &lt;process-engine&gt; + + &lt;repository-service /&gt; + &lt;repository-cache /&gt; + &lt;execution-service /&gt; + &lt;history-service /&gt; + &lt;management-service /&gt; + &lt;identity-service /&gt; + &lt;task-service /&gt;</programlisting> + <para>And the file <literal>jbpm.tx.hibernate.cfg.xml</literal> contains the + following command service configuration:</para> + <programlisting>&lt;jbpm-configuration&gt; + + &lt;process-engine-context&gt; + &lt;command-service&gt; + &lt;retry-interceptor /&gt; + &lt;environment-interceptor /&gt; + &lt;standard-transaction-interceptor /&gt; + &lt;/command-service&gt; + &lt;/process-engine-context&gt; + + ...</programlisting> + <para>The services like e.g. <literal>repository-service</literal>, <literal>execution-service</literal> + and <literal>management-service</literal> will look up the configured + <literal>command-service</literal> by type. The <literal>command-service</literal> + tag corresponds to the default command service that essentially does nothing else + then just execute the command providing it the current environment. + </para> + <para>The configured <literal>command-service</literal> results into the following + a chain of three interceptors followed by the default command executor. + </para> + <figure id="interceptors"> + <title>The CommandService interceptors</title> + <mediaobject><imageobject><imagedata align="center" fileref="images/interceptors.png"/></imageobject></mediaobject> + </figure> + <para>The retry interceptor is the first in the chain and that one that will be exposed as the + <literal>CommandService.class</literal> from the environment. So the retry interceptor + will be given to the respective services <literal>repository-service</literal>, <literal>execution-service</literal> + and <literal>management-service</literal>. + </para> + <para>The <literal>retry-interceptor</literal> will catch hibernate StaleObjectExceptions + (indicating optimistic locking failures) and retry to execute the command. + </para> + <para>The <literal>environment-interceptor</literal> will put an environment block + around the execution of the command. + </para> + <para>The <literal>standard-transaction-interceptor</literal> will initialize a + <literal>StandardTransaction</literal>. The hibernate session/transaction will be + enlisted as a resource with this standard transaction. + </para> + <para>Different configurations of this interceptor stack will also enable to + </para> + <itemizedlist> + <listitem>delegate execution to a local ejb command service so that an container + managed transaction is started. + </listitem> + <listitem>delegate to a remote ejb command service so that the command actually + gets executed on a different JVM. + </listitem> + <listitem>package the command as an asynchronous message so that the command gets + executed asynchronously in a different transaction. + </listitem> + </itemizedlist> + </section> + +</chapter> \ No newline at end of file Deleted: jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch04-ImplementingBasicActivities.xml =================================================================== --- jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch04-ImplementingBasicActivities.xml 2009-05-06 12:55:13 UTC (rev 4748) +++ jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch04-ImplementingBasicActivities.xml 2009-05-06 14:03:44 UTC (rev 4749) @@ -1,490 +0,0 @@ -<chapter id="implementingbasicactivities"> - <title>Implementing basic activities</title> - - <para>This chapter explains the basics of process definitions, the features offered by - the Process Virtual Machine and how activity implementations can be build. At the same - time the client API is shown to execute processes with those activity implementations. - </para> - - <!-- ### Activity ####################################################### --> - <section id="activity"> - <title>Activity</title> - <para>The PVM library doesn't have a fixed set of process constructs. - Instead, runtime behaviour of a activity is delegated to an <literal>Activity</literal>. - In other words, <literal>Activity</literal> is an interface to implement the runtime - behaviour of process constructs in plain Java. - </para> - <programlisting>public <emphasis role="bold">interface Activity</emphasis> extends Serializable { - - void <emphasis role="bold">execute</emphasis>(ActivityExecution execution) throws Exception; - -}</programlisting> - <para>When an activity is used as the activity behaviour, it is in full control of the further - propagation of the execution. In other words, a activity behaviour can decide what the execution - should do next. For example, it can take a transition with - <literal>execution.take(Transition)</literal> or go into a wait state with - <literal>execution.waitForSignal()</literal>. In case the activity behaviour does not invoke - any of the above execution propagation methods, the execution will - <link linkend="implicitproceedbehaviour">proceed in a default way</link>. - </para> - </section> - - <!-- ### Activity example ############################################### --> - <section id="activityexample"> - <title>Activity example</title> - <para>We'll start with a very original hello world example. A Display - activity will print a message to the console: - </para> - <programlisting>public <emphasis role="bold">class Display</emphasis> implements <emphasis role="bold">Activity</emphasis> { - - String message; - - public Display(String message) { - this.message = message; - } - - public void execute(ActivityExecution execution) { - <emphasis role="bold">System.out.println(message);</emphasis> - } -}</programlisting> - <para>Let' build our first process definition with this activity:</para> - <figure id="activity.example"> - <title>Display example process</title> - <mediaobject><imageobject><imagedata align="center" fileref="images/process.ab.png"/></imageobject></mediaobject> - </figure> - <programlisting>ClientProcessDefinition processDefinition = ProcessFactory.build() - .<emphasis role="bold">activity("a").initial()</emphasis>.behaviour(<emphasis role="bold">new Display("hello")</emphasis>) - .transition().to("b") - .<emphasis role="bold">activity("b")</emphasis>.behaviour(<emphasis role="bold">new Display("world")</emphasis>) -.done();</programlisting> - <para>Now we can execute this process as follows:</para> - <programlisting>Execution execution = processDefinition.startExecution();</programlisting> - <para>The invocation of <literal>startExecution</literal> will print hello world to the console:</para> - <programlisting>hello -world</programlisting> - <para>One thing already worth noticing is that activities can be configured - with properties. In the Display example, you can see that the message property - is configured differently in the two usages. With configuration properties - it becomes possible to write reusable activities. They can then be configured - differently each time they are used in a process. That is an essential part of - how process languages can be build on top of the Process Virtual Machine. - </para> - <para>The other part that needs explanation is that this activity - implementation does not contain any instructions for the propagation of the - execution. When a new process instance is started, the execution is positioned - in the initial activity and that activity is executed. The method - <literal>Display.execute</literal> makes use of what is called implicit propagation - of execution. Concretely this means that the activity itself does not - invoke any of the methods on the execution to propagate it. In that case - implicit propagation kicks in. Implicit propagation will take the first - transition if there is one. If not, it will end the execution. This explains - why both activities <literal>a</literal> and <literal>b</literal> are executed and that - the execution stops after activity <literal>b</literal> is executed. - </para> - <para>More details about the implicit proceed behaviour can be found - in <xref linkend="implicitproceedbehaviour" /></para> - </section> - - <!-- ### ExternalActivity ############################################### --> - <section id="externalactivity"> - <title>ExternalActivity</title> - <para>External activities are activities for which the responsibility for proceeding - the execution is transferred externally, meaning outside the process system. This - means that for the system that is executing the process, it's a wait state. The - execution will wait until an external trigger is given. - </para> - <para>For dealing with external triggers, <literal>ExternalActivity</literal> - adds two methods to the <literal>Activity</literal>:</para> - <programlisting>public <emphasis role="bold">interface ExternalActivity</emphasis> extends <emphasis role="bold">Activity</emphasis> { - - void <emphasis role="bold">signal</emphasis>(Execution execution, - String signal, - Map&lt;String, Object&gt; parameters) throws Exception; - -}</programlisting> - <para>Just like with plain activities, when an execution arrives in a activity, the - <literal>execute</literal>-method of the activity behaviour is invoked. - In external activities, the execute method typically does something to - transfer the responsibility to another system and then enters a wait - state by invoking <literal>execution.waitForSignal()</literal>. For - example in the execute method, responsibility could be transferred to a - person by creating a task entry in a task management system and then - wait until the person completes the task. - </para> - <para>In case a activity behaves as a wait state, then the execution will - wait in that activity until the execution's <literal>signal</literal> method - is invoked. The execution will delegate that signal to the behaviour Activity - of the current activity. - </para> - <para>So the Activity's <literal>signal</literal>-method is invoked - when the execution receives an external trigger during the wait state. With the - signal method, responsibility is transferred back to the process execution. For - example, when a person completes a task, the task management system calls the - signal method on the execution. - </para> - <para>A signal can optionally have a signal name and a map of parameters. Most - common way on how activity behaviours interprete the signal and parameters is that - the signal relates to the outgoing transition that needs to be taken and that the - parameters are set as variables on the execution. But those are just examples, it - is up to the activity to use the signal and the parameters as it pleases. - </para> - </section> - - <!-- ### ExternalActivity example ####################################### --> - <section id="externalactivityexample"> - <title>ExternalActivity example</title> - <para>Here's a first example of a simple wait state implementation: - </para> - <programlisting>public <emphasis role="bold">class WaitState</emphasis> implements <emphasis role="bold">ExternalActivity</emphasis> { - - public void execute(ActivityExecution execution) { - <emphasis role="bold">execution.waitForSignal();</emphasis> - } - - public void signal(ActivityExecution execution, - String signalName, - Map&lt;String, Object&gt; parameters) { - <emphasis role="bold">execution.take(signalName);</emphasis> - } -}</programlisting> - <para>The <literal>execute</literal>-method calls - <literal>execution.waitForSignal()</literal>. The invocation of - <literal>execution.waitForSignal()</literal> will bring the process execution - into a wait state until an external trigger is given. - </para> - <para><literal>signal</literal>-method takes the transition with - the signal parameter as the transition name. So when an execution receives an - external trigger, the signal name is interpreted as the name of an outgoing - transition and the execution will be propagated over that transition. - </para> - <para>Here's the same simple process that has a transition from a to b. This - time, the behaviour of the two activities will be WaitState's. - </para> - <figure id="process.diagram"> - <title>The external activity example process</title> - <mediaobject><imageobject><imagedata align="center" fileref="images/process.ab.png"/></imageobject></mediaobject> - </figure> - <programlisting>ClientProcessDefinition processDefinition = ProcessFactory.build() - <emphasis role="bold">.activity("a").initial().behaviour(new WaitState())</emphasis> - .transition().to("b") - <emphasis role="bold">.activity("b").behaviour(new WaitState())</emphasis> -.done();</programlisting> - <para>Let's start a new process instance for this process definition:</para> - <programlisting>ClientExecution execution = processDefinition.startProcessInstance();</programlisting> - <para>Starting this process will execute the <literal>WaitState</literal> activity - in activity <literal>a</literal>. <literal>WaitState.execute</literal> will invoke - <literal>ActivityExecution.waitForSignal</literal>. So when the - <literal>processDefinition.startProcessInstance()</literal> returns, the execution - will still be positioned in activity a. - </para> - <programlisting>assertEquals("a", execution.getActivityName());</programlisting> - <para>Then we provide the external trigger by calling the <literal>signal</literal> - method. - </para> - <programlisting>execution.signal();</programlisting> - <para>The <literal>execution.signal()</literal> will delegate to the activity - of the current activity. So in this case that is the <literal>WaitState</literal> - activity in activity <literal>a</literal>. The <literal>WaitState.signal</literal> - will invoke the <literal>ActivityExecution.take(String transitionName)</literal>. - Since we didn't supply a signalName, the first transition with name <literal>null</literal> - will be taken. The only transition we specified out of activity <literal>a</literal> - didn't get a name so that one will be taken. And that transition points to activity - <literal>b</literal>. When the execution arrives in activity <literal>b</literal>, - the <literal>WaitState</literal> in activity <literal>b</literal> is executed. - Similar as we saw above, the execution will wait in activity <literal>b</literal> - and this time the <literal>signal</literal> method will return, leaving the - execution positioned in activity <literal>b</literal>. - </para> - <programlisting>assertEquals("b", execution.getActivityName());</programlisting> - </section> - - <!-- ### BASIC PROCESS EXECUTION ######################################## --> - <section id="basicprocessexecution"> - <title>Basic process execution</title> - <para>In this next example, we'll combine automatic activities and wait states. - This example builds upon the loan approval process with the <literal>WaitState</literal> - and <literal>Display</literal> activities that we've just created. Graphically, - the loan process looks like this: - </para> - <figure id="basicprocessexecution.loan.process"> - <title>The loan process</title> - <mediaobject><imageobject><imagedata align="center" fileref="images/process.loan.png"/></imageobject></mediaobject> - </figure> - <para>Building process graphs in Java code can be tedious because you have to keep track of all the - references in local variables. To resolve that, the Process Virtual Machine comes with a - ProcessFactory. The ProcessFactory is a kind of domain specific language (DSL) that is embedded - in Java and eases the construction of process graphs. This pattern is also known as - a <ulink url="http://martinfowler.com/bliki/FluentInterface.html">fluent - interface</ulink>. - </para> - <programlisting>ClientProcessDefinition processDefinition = ProcessFactory.build("loan") - .activity(<emphasis role="bold">"submit loan request"</emphasis>).initial().behaviour(new Display("loan request submitted")) - .transition().to("evaluate") - <emphasis role="bold">.activity("evaluate").behaviour(new WaitState())</emphasis> - .transition("approve").to("wire money") - .transition("reject").to("end") - <emphasis role="bold">.activity("wire money").behaviour(new Display("wire the money"))</emphasis> - .transition().to("archive") - <emphasis role="bold">.activity("archive").behaviour(new WaitState())</emphasis> - .transition().to("end") - <emphasis role="bold">.activity("end").behaviour(new WaitState())</emphasis> -.done();</programlisting> - <para>For more details about the ProcessFactory, see <ulink url="../../api/org/jbpm/pvm/package-summary.html">the - api docs</ulink>. An alternative for - the ProcessFactory would be to create an XML language and an XML parser for expressing - processes. The XML parser can then instantiate the classes of package - <literal>org.jbpm.pvm.internal.model</literal> directly. That approach is typically taken by - process languages. - </para> - <para>The initial activity <literal>submit loan request</literal> and the activity - <literal>wire the money</literal> are automatic activities. In this example, - the <literal>Display</literal> implementation of activity - <literal>wire the money</literal> uses the Java API's to just print a - message to the console. But the witty reader can imagine an alternative - <literal>Activity</literal> implementation that uses the Java API of a payment - processing library to make a real automatic payment. - </para> - <para>A new execution for the process above can be started like this - </para> - <programlisting>ClientExecution execution = processDefinition.startProcessInstance();</programlisting> - <para>When the <literal>startExecution</literal>-method returns, the activity - <literal>submit loan request</literal> will be executed and the execution will be - positioned in the activity <literal>evaluate</literal>. - </para> - <figure id="execution.loan.evaluate"> - <title>Execution positioned in the 'evaluate' activity</title> - <mediaobject><imageobject><imagedata align="center" fileref="images/execution.loan.evaluate.png"/></imageobject></mediaobject> - </figure> - <para>Now, the execution is at an interesting point. There are two transitions out of - the state <literal>evaluate</literal>. One transition is called <literal>approve</literal> - and one transition is called <literal>reject</literal>. As we explained above, the WaitState - implementation will take the transition that corresponds to the signal that is given. - Let's feed in the 'approve' signal like this: - </para> - <programlisting>execution.signal("approve");</programlisting> - <para>The <literal>approve</literal> signal will cause the execution to take the <literal>approve</literal> - transition and it will arrive in the activity <literal>wire money</literal>. - </para> - <para>In activity <literal>wire money</literal>, the message will be printed to the console. - Since, the <literal>Display</literal> activity didn't invoke the - <literal>execution.waitForSignal()</literal>, nor any of the other execution propagation - methods, the implicit proceed behaviour will just make the execution continue - over the outgoing transition to activity <literal>archive</literal>, which is again - a <literal>WaitState</literal>. - </para> - <figure id="execution.loan.archive"> - <title>Execution positioned in 'archive' activity</title> - <mediaobject><imageobject><imagedata align="center" fileref="images/execution.loan.archive.png"/></imageobject></mediaobject> - </figure> - <para>So only when the <literal>archive</literal> wait state is reached, - the <literal>signal("approve")</literal> returns. - </para> - <para>Another signal like this:</para> - <programlisting>execution.signal("approve");</programlisting> - <para>will bring the execution eventually in the end state.</para> - <figure id="execution.loan.end"> - <title>Execution positioned in the 'end' activity</title> - <mediaobject><imageobject><imagedata align="center" fileref="images/execution.loan.end.png"/></imageobject></mediaobject> - </figure> - </section> - - <!-- ### EVENTS ######################################################### --> - <section id="events"> - <title>Events</title> - <para>Events are points in the process definition to which a list of - <literal>EventListener</literal>s can be subscribed. - </para> - <programlisting>public interface EventListener extends Serializable { - - void notify(EventListenerExecution execution) throws Exception; - -}</programlisting> - <para>The motivation for events is to allow for - developers to add programming logic to a process without changing the process diagram. - This is a very valuable instrument in facilitating the collaboration between business analysts - and developers. Business analysts - are responsible for expressing the requirements. When they use a process graph to document - those requirements, developers can take this diagram and make it executable. Events can - be a very handy to insert technical details into a process (like e.g. some database insert) - in which the business analyst is not interested. - </para> - <para>Most common events are fired by the execution automatically: - </para> - <para>TODO: explain events in userguide</para> - <para>Events are identified by the combination of a process element - and an event name. Users and process languages can also fire events - programmatically with the fire method on the Execution: - </para> - <programlisting>public interface Execution extends Serializable { - ... - void fire(String eventName, ProcessElement eventSource); - ... -}</programlisting> - - <para>A list of <literal>EventListeners</literal> can be associated to an - event. But event listeners can not influence the control flow of the execution since - they are merely listeners to an execution which is already in progress. This is different from - activities that serve as the behaviour for activities. Activity behaviour activities are responsible - for propagating the execution. - </para> - <para>We'll create a <literal>PrintLn</literal> event listener which is - very similar to the <literal>Display</literal> activity from above. - </para> - <programlisting>public class PrintLn implements EventListener { - - String message; - - public PrintLn(String message) { - this.message = message; - } - - public void notify(EventListenerExecution execution) throws Exception { - System.out.println("message"); - } -}</programlisting> - <para>Several <literal>PrintLn</literal> listeners will be subscribed to events in - the process.</para> - <figure id="action.process"> - <title>The PrintLn listener process</title> - <mediaobject><imageobject><imagedata align="center" fileref="images/process.ab.png"/></imageobject></mediaobject> - </figure> - <programlisting>ClientProcessDefinition processDefinition = ProcessFactory.build() - .activity("a").initial().behaviour(new AutomaticActivity()) - <emphasis role="bold">.event("end") - .listener(new PrintLn("leaving a")) - .listener(new PrintLn("second message while leaving a"))</emphasis> - .transition().to("b") - <emphasis role="bold">.listener(new PrintLn("taking transition"))</emphasis> - .activity("b").behaviour(new WaitState()) - .event("start") - <emphasis role="bold">.listener(new PrintLn("entering b"))</emphasis> -.done();</programlisting> - <para>The first event shows how to register multiple listeners to the same - event. They will be notified in the order as they are specified. - </para> - <para>Then, on the transition, there is only one type of event. So in that case, - the event type must not be specified and the listeners can be added directly on - the transition. - </para> - <para>A listeners will be called each time an execution fires the event to - which the listener is subscribed. The execution will be provided in the activity - interface as a parameter and can be used by listeners except for the methods that - control the propagation of execution. - </para> - </section> - - <!-- ### EVENT PROPAGATION ############################################## --> - <section> - <title>Event propagation</title> - <para>Events are by default propagated to enclosing process elements. The motivation - is to allow for listeners on process definitions or composite activities that get executed - for all events that occur within that process element. For example this feature - allows to register an event listener on a process definition or a composite activity on - <literal>end</literal> events. Such action will be executed if that activity is - left. And if that event listener is registered on a composite activity, it will also be executed - for all activities that are left within that composite activity. - </para> - <para>To show this clearly, we'll create a <literal>DisplaySource</literal> event listener - that will print the message <literal>leaving</literal> and the source of the event - to the console. - </para> - <programlisting>public class <emphasis role="bold">DisplaySource</emphasis> implements EventListener { - - public void execute(EventListenerExecution execution) { - <emphasis role="bold">System.out.println("leaving "+execution.getEventSource());</emphasis> - } -}</programlisting> - <para>Note that the purpose of event listeners is not to be visible, that's why the event listener - itself should not be displayed in the diagram. A <literal>DisplaySource</literal> event listener - will be added as a listener to the event <literal>end</literal> on the composite activity. - </para> - <para>The next process shows how the <literal>DisplaySource</literal> event listener is registered - as a listener to to the 'end' event on the <literal>composite</literal> activity:</para> - <figure id="process.propagate"> - <title>A process with an invisible event listener on a end event on a composite activity.</title> - <mediaobject><imageobject><imagedata align="center" fileref="images/process.propagate.png"/></imageobject></mediaobject> - </figure> - <programlisting>TODO update code snippet</programlisting> - <para>Next we'll start an execution.</para> - <programlisting>ClientExecution execution = processDefinition.startProcessInstance();</programlisting> - <para>After starting a new execution, the execution will be in activity <literal>a</literal> as - that is the initial activity. No activities have been left so no message is logged. Next a signal - will be given to the execution, causing it to take the transition from <literal>a</literal> - to <literal>b</literal>. - </para> - <programlisting>execution.signal();</programlisting> - <para>When the signal method returns, the execution will have taken the transition and - the <literal>end</literal> event will be fired on activity <literal>a</literal>. That - event will be propagated to the - composite activity and to the process definition. Since our <literal>DisplaySource</literal> - event listener is placed - on the <literal>composite</literal> activity, it will receive the event and print the following - message on the console: - </para> - <programlisting>leaving activity(a)</programlisting> - <para>Another</para> - <programlisting>execution.signal();</programlisting> - <para>will take the transition from b to c. That will fire two activity-leave events. One on - activity b and one on activity composite. So the following lines will be appended to the console - output:</para> - <programlisting>leaving activity(b) -leaving activity(composite)</programlisting> - <para>Event propagation is build on the hierarchical composition structure of the process - definition. The top level element is always the process definition. The process - definition contains a list of activities. Each activity can be a leaf activity or it can be a - composite activity, which means that it contains a list of nested activities. Nested activities - can be used for e.g. super states or composite activities in nested process languages like BPEL. - </para> - <para>So the even model also works similarly for composite activities as it did for the process - definition above. Suppose that 'Phase one' models - a super state as in state machines. Then event propagation allows to subscribe to all events - within that super state. The idea is that the hierarchical composition corresponds to - diagram representation. If an element 'e' is drawn inside another element 'p', then p - is the parent of e. A process definition has a set of top level activities. Every activity can have - a set of nested activities. The parent of a transition is considered as the first common - parent for it's source and destination. - </para> - <para>If an event listener is not interested in propagated events, propagation can be disabled - with <literal>propagationDisabled()</literal> while building the process with the - <literal>ProcessFactory</literal>. The next process is the same process - as above except that propagated events will be disabled on the event listener. The graph diagram - remains the same. - </para> - <figure id="process.propagate.propagation.disabled"> - <title>A process with an event listener to 'end' events with propagation disabled.</title> - <mediaobject><imageobject><imagedata align="center" fileref="images/process.propagate.png"/></imageobject></mediaobject> - </figure> - <para>Building the process with the process factory: - </para> - <programlisting>TODO update code snippet</programlisting> - <para>So when the first signal is given for this process, again the <literal>end</literal> - event will be fired on activity <literal>a</literal>, but now the event listener on the composite - activity will not be executed cause - propagated events have been disabled. Disabling propagation is a property on the individual - event listener and doesn't influence the other listeners. The event will always be fired and - propagated over the whole parent hierarchy. - </para> - <programlisting>ClientExecution execution = processDefinition.startProcessInstance();</programlisting> - <para>The first signal will take the process from <literal>a</literal> to - <literal>b</literal>. No messages will be printed to the console. - </para> - <programlisting>execution.signal();</programlisting> - <para>Next, the second signal will take the transition from b to c. - </para> - <programlisting>execution.signal()</programlisting> - <para>Again two <literal>end</literal> - events are fired just like above on activities <literal>b</literal> and <literal>composite</literal> - respectively. The first event - is the <literal>end</literal> event on activity <literal>b</literal>. That will be propagated - to the <literal>composite</literal> activity. So the event - listener will not be executed for this event cause it has propagation disabled. But the - event listener will be executed for the <literal>end</literal> event on the - <literal>composite</literal> activity. That is not - propagated, but fired directly on the <literal>composite</literal> activity. So the event - listener will now be executed - only once for the composite activity as shown in the following console output: - </para> - <programlisting>leaving activity(composite)</programlisting> - </section> - -</chapter> Copied: jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch05-ImplementingBasicActivities.xml (from rev 4742, jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch04-ImplementingBasicActivities.xml) =================================================================== --- jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch05-ImplementingBasicActivities.xml (rev 0) +++ jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch05-ImplementingBasicActivities.xml 2009-05-06 14:03:44 UTC (rev 4749) @@ -0,0 +1,486 @@ +<chapter id="implementingbasicactivities"> + <title>Implementing basic activities</title> + + <para>This chapter explains the basics of process definitions, the features offered by + the Process Virtual Machine and how activity implementations can be build. At the same + time the client API is shown to execute processes with those activity implementations. + </para> + + <!-- ### Activity ####################################################### --> + <section id="activity"> + <title>ActivityBehaviour</title> + <para>The PVM library doesn't have a fixed set of process constructs. + Instead, runtime behaviour of a activity is delegated to an <literal>ActivityBehaviour</literal>. + In other words, <literal>ActivityBehaviour</literal> is an interface to implement the runtime + behaviour of process constructs in plain Java. + </para> + <programlisting>public <emphasis role="bold">interface ActivityBehaviour</emphasis> extends Serializable { + + void <emphasis role="bold">execute</emphasis>(ActivityExecution execution) throws Exception; + +}</programlisting> + <para>When an activity behaviour is called, it is in full control of the further + propagation of the execution. In other words, an activity behaviour can decide what the execution + should do next. For example, it can take a transition with + <literal>execution.take(Transition)</literal> or go into a wait state with + <literal>execution.waitForSignal()</literal>. In case the activity behaviour does not invoke + any of the above execution propagation methods, the execution will + <link linkend="implicitproceedbehaviour">proceed in a default way</link>. + </para> + </section> + + <!-- ### ActivityBehaviour example ############################################### --> + <section id="activitybehaviourexample"> + <title>ActivityBehaviour example</title> + <para>We'll start with a very original hello world example. A Display + activity will print a message to the console: + </para> + <programlisting>public <emphasis role="bold">class Display</emphasis> implements <emphasis role="bold">ActivityBehaviour</emphasis> { + + String message; + + public Display(String message) { + this.message = message; + } + + public void execute(ActivityExecution execution) { + <emphasis role="bold">System.out.println(message);</emphasis> + } +}</programlisting> + <para>Let' build our first process definition with this activity:</para> + <figure id="activity.example"> + <title>Display example process</title> + <mediaobject><imageobject><imagedata align="center" fileref="images/process.ab.png"/></imageobject></mediaobject> + </figure> + <programlisting>TODO add ProcessBuilder example code</programlisting> + <para>Now we can execute this process as follows:</para> + <programlisting>Execution execution = processDefinition.startExecution();</programlisting> + <para>The invocation of <literal>startExecution</literal> will print hello world to the console:</para> + <programlisting>hello +world</programlisting> + <para>One thing already worth noticing is that activities can be configured + with properties. In the Display example, you can see that the message property + is configured differently in the two usages. With configuration properties + it becomes possible to write reusable activities. They can then be configured + differently each time they are used in a process. That is an essential part of + how process languages can be build on top of the Process Virtual Machine. + </para> + <para>The other part that needs explanation is that this activity + implementation does not contain any instructions for the propagation of the + execution. When a new process instance is started, the execution is positioned + in the initial activity and that activity is executed. The method + <literal>Display.execute</literal> makes use of what is called implicit propagation + of execution. Concretely this means that the activity itself does not + invoke any of the methods on the execution to propagate it. In that case + implicit propagation kicks in. Implicit propagation will take the first + transition if there is one. If not, it will end the execution. This explains + why both activities <literal>a</literal> and <literal>b</literal> are executed and that + the execution stops after activity <literal>b</literal> is executed. + </para> + <para>More details about the implicit proceed behaviour can be found + in <xref linkend="implicitproceedbehaviour" /></para> + </section> + + <!-- ### ExternalActivityBehaviour ############################################### --> + <section id="externalactivitybehaviour"> + <title>ExternalActivityBehaviour</title> + <para>External activities are activities for which the responsibility for proceeding + the execution is transferred externally, meaning outside the process system. This + means that for the system that is executing the process, it's a wait state. The + execution will wait until an external trigger is given. + </para> + <para>For dealing with external triggers, <literal>ExternalActivityBehaviour</literal> + adds one method to the <literal>ActivityBehaviour</literal>:</para> + <programlisting>public <emphasis role="bold">interface ExternalActivity</emphasis> extends <emphasis role="bold">Activity</emphasis> { + + void <emphasis role="bold">signal</emphasis>(Execution execution, + String signal, + Map&lt;String, Object&gt; parameters) throws Exception; + +}</programlisting> + <para>Just like with plain activities, when an execution arrives in a activity, the + <literal>execute</literal>-method of the external activity behaviour is invoked. + In external activities, the execute method typically does something to + transfer the responsibility to another system and then enters a wait + state by invoking <literal>execution.waitForSignal()</literal>. For + example in the execute method, responsibility could be transferred to a + person by creating a task entry in a task management system and then + wait until the person completes the task. + </para> + <para>In case a activity behaves as a wait state, then the execution will + wait in that activity until the execution's <literal>signal</literal> method + is invoked. The execution will delegate that signal to the ExternalActivityBehaviour + object associated to the current activity. + </para> + <para>So the Activity's <literal>signal</literal>-method is invoked + when the execution receives an external trigger during the wait state. With the + signal method, responsibility is transferred back to the process execution. For + example, when a person completes a task, the task management system calls the + signal method on the execution. + </para> + <para>A signal can optionally have a signal name and a map of parameters. Most + common way on how activity behaviours interprete the signal and parameters is that + the signal relates to the outgoing transition that needs to be taken and that the + parameters are set as variables on the execution. But those are just examples, it + is up to the activity to use the signal and the parameters as it pleases. + </para> + </section> + + <!-- ### ExternalActivity example ####################################### --> + <section id="externalactivityexample"> + <title>ExternalActivity example</title> + <para>Here's a first example of a simple wait state implementation: + </para> + <programlisting>public <emphasis role="bold">class WaitState</emphasis> implements <emphasis role="bold">ExternalActivity</emphasis> { + + public void execute(ActivityExecution execution) { + <emphasis role="bold">execution.waitForSignal();</emphasis> + } + + public void signal(ActivityExecution execution, + String signalName, + Map&lt;String, Object&gt; parameters) { + <emphasis role="bold">execution.take(signalName);</emphasis> + } +}</programlisting> + <para>The <literal>execute</literal>-method calls + <literal>execution.waitForSignal()</literal>. The invocation of + <literal>execution.waitForSignal()</literal> will bring the process execution + into a wait state until an external trigger is given. + </para> + <para><literal>signal</literal>-method takes the transition with + the signal parameter as the transition name. So when an execution receives an + external trigger, the signal name is interpreted as the name of an outgoing + transition and the execution will be propagated over that transition. + </para> + <para>Here's the same simple process that has a transition from a to b. This + time, the behaviour of the two activities will be WaitState's. + </para> + <figure id="process.diagram"> + <title>The external activity example process</title> + <mediaobject><imageobject><imagedata align="center" fileref="images/process.ab.png"/></imageobject></mediaobject> + </figure> + <programlisting>ClientProcessDefinition processDefinition = ProcessFactory.build() + <emphasis role="bold">.activity("a").initial().behaviour(new WaitState())</emphasis> + .transition().to("b") + <emphasis role="bold">.activity("b").behaviour(new WaitState())</emphasis> +.done();</programlisting> + <para>Let's start a new process instance for this process definition:</para> + <programlisting>ClientExecution execution = processDefinition.startProcessInstance();</programlisting> + <para>Starting this process will execute the <literal>WaitState</literal> activity + in activity <literal>a</literal>. <literal>WaitState.execute</literal> will invoke + <literal>ActivityExecution.waitForSignal</literal>. So when the + <literal>processDefinition.startProcessInstance()</literal> returns, the execution + will still be positioned in activity a. + </para> + <programlisting>assertEquals("a", execution.getActivityName());</programlisting> + <para>Then we provide the external trigger by calling the <literal>signal</literal> + method. + </para> + <programlisting>execution.signal();</programlisting> + <para>The <literal>execution.signal()</literal> will delegate to the activity + of the current activity. So in this case that is the <literal>WaitState</literal> + activity in activity <literal>a</literal>. The <literal>WaitState.signal</literal> + will invoke the <literal>ActivityExecution.take(String transitionName)</literal>. + Since we didn't supply a signalName, the first transition with name <literal>null</literal> + will be taken. The only transition we specified out of activity <literal>a</literal> + didn't get a name so that one will be taken. And that transition points to activity + <literal>b</literal>. When the execution arrives in activity <literal>b</literal>, + the <literal>WaitState</literal> in activity <literal>b</literal> is executed. + Similar as we saw above, the execution will wait in activity <literal>b</literal> + and this time the <literal>signal</literal> method will return, leaving the + execution positioned in activity <literal>b</literal>. + </para> + <programlisting>assertEquals("b", execution.getActivityName());</programlisting> + </section> + + <!-- ### BASIC PROCESS EXECUTION ######################################## --> + <section id="basicprocessexecution"> + <title>Basic process execution</title> + <para>In this next example, we'll combine automatic activities and wait states. + This example builds upon the loan approval process with the <literal>WaitState</literal> + and <literal>Display</literal> activities that we've just created. Graphically, + the loan process looks like this: + </para> + <figure id="basicprocessexecution.loan.process"> + <title>The loan process</title> + <mediaobject><imageobject><imagedata align="center" fileref="images/process.loan.png"/></imageobject></mediaobject> + </figure> + <para>Building process graphs in Java code can be tedious because you have to keep track of all the + references in local variables. To resolve that, the Process Virtual Machine comes with a + ProcessFactory. The ProcessFactory is a kind of domain specific language (DSL) that is embedded + in Java and eases the construction of process graphs. This pattern is also known as + a <ulink url="http://martinfowler.com/bliki/FluentInterface.html">fluent + interface</ulink>. + </para> + <programlisting>ClientProcessDefinition processDefinition = ProcessFactory.build("loan") + .activity(<emphasis role="bold">"submit loan request"</emphasis>).initial().behaviour(new Display("loan request submitted")) + .transition().to("evaluate") + <emphasis role="bold">.activity("evaluate").behaviour(new WaitState())</emphasis> + .transition("approve").to("wire money") + .transition("reject").to("end") + <emphasis role="bold">.activity("wire money").behaviour(new Display("wire the money"))</emphasis> + .transition().to("archive") + <emphasis role="bold">.activity("archive").behaviour(new WaitState())</emphasis> + .transition().to("end") + <emphasis role="bold">.activity("end").behaviour(new WaitState())</emphasis> +.done();</programlisting> + <para>For more details about the ProcessFactory, see <ulink url="../../api/org/jbpm/pvm/package-summary.html">the + api docs</ulink>. An alternative for + the ProcessFactory would be to create an XML language and an XML parser for expressing + processes. The XML parser can then instantiate the classes of package + <literal>org.jbpm.pvm.internal.model</literal> directly. That approach is typically taken by + process languages. + </para> + <para>The initial activity <literal>submit loan request</literal> and the activity + <literal>wire the money</literal> are automatic activities. In this example, + the <literal>Display</literal> implementation of activity + <literal>wire the money</literal> uses the Java API's to just print a + message to the console. But the witty reader can imagine an alternative + <literal>Activity</literal> implementation that uses the Java API of a payment + processing library to make a real automatic payment. + </para> + <para>A new execution for the process above can be started like this + </para> + <programlisting>ClientExecution execution = processDefinition.startProcessInstance();</programlisting> + <para>When the <literal>startExecution</literal>-method returns, the activity + <literal>submit loan request</literal> will be executed and the execution will be + positioned in the activity <literal>evaluate</literal>. + </para> + <figure id="execution.loan.evaluate"> + <title>Execution positioned in the 'evaluate' activity</title> + <mediaobject><imageobject><imagedata align="center" fileref="images/execution.loan.evaluate.png"/></imageobject></mediaobject> + </figure> + <para>Now, the execution is at an interesting point. There are two transitions out of + the state <literal>evaluate</literal>. One transition is called <literal>approve</literal> + and one transition is called <literal>reject</literal>. As we explained above, the WaitState + implementation will take the transition that corresponds to the signal that is given. + Let's feed in the 'approve' signal like this: + </para> + <programlisting>execution.signal("approve");</programlisting> + <para>The <literal>approve</literal> signal will cause the execution to take the <literal>approve</literal> + transition and it will arrive in the activity <literal>wire money</literal>. + </para> + <para>In activity <literal>wire money</literal>, the message will be printed to the console. + Since, the <literal>Display</literal> activity didn't invoke the + <literal>execution.waitForSignal()</literal>, nor any of the other execution propagation + methods, the implicit proceed behaviour will just make the execution continue + over the outgoing transition to activity <literal>archive</literal>, which is again + a <literal>WaitState</literal>. + </para> + <figure id="execution.loan.archive"> + <title>Execution positioned in 'archive' activity</title> + <mediaobject><imageobject><imagedata align="center" fileref="images/execution.loan.archive.png"/></imageobject></mediaobject> + </figure> + <para>So only when the <literal>archive</literal> wait state is reached, + the <literal>signal("approve")</literal> returns. + </para> + <para>Another signal like this:</para> + <programlisting>execution.signal("approve");</programlisting> + <para>will bring the execution eventually in the end state.</para> + <figure id="execution.loan.end"> + <title>Execution positioned in the 'end' activity</title> + <mediaobject><imageobject><imagedata align="center" fileref="images/execution.loan.end.png"/></imageobject></mediaobject> + </figure> + </section> + + <!-- ### EVENTS ######################################################### --> + <section id="events"> + <title>Events</title> + <para>Events are points in the process definition to which a list of + <literal>EventListener</literal>s can be subscribed. + </para> + <programlisting>public interface EventListener extends Serializable { + + void notify(EventListenerExecution execution) throws Exception; + +}</programlisting> + <para>The motivation for events is to allow for + developers to add programming logic to a process without changing the process diagram. + This is a very valuable instrument in facilitating the collaboration between business analysts + and developers. Business analysts + are responsible for expressing the requirements. When they use a process graph to document + those requirements, developers can take this diagram and make it executable. Events can + be a very handy to insert technical details into a process (like e.g. some database insert) + in which the business analyst is not interested. + </para> + <para>Most common events are fired by the execution automatically: + </para> + <para>TODO: explain events in userguide</para> + <para>Events are identified by the combination of a process element + and an event name. Users and process languages can also fire events + programmatically with the fire method on the Execution: + </para> + <programlisting>public interface Execution extends Serializable { + ... + void fire(String eventName, ProcessElement eventSource); + ... +}</programlisting> + + <para>A list of <literal>EventListeners</literal> can be associated to an + event. But event listeners can not influence the control flow of the execution since + they are merely listeners to an execution which is already in progress. This is different from + activities that serve as the behaviour for activities. Activity behaviour activities are responsible + for propagating the execution. + </para> + <para>We'll create a <literal>PrintLn</literal> event listener which is + very similar to the <literal>Display</literal> activity from above. + </para> + <programlisting>public class PrintLn implements EventListener { + + String message; + + public PrintLn(String message) { + this.message = message; + } + + public void notify(EventListenerExecution execution) throws Exception { + System.out.println("message"); + } +}</programlisting> + <para>Several <literal>PrintLn</literal> listeners will be subscribed to events in + the process.</para> + <figure id="action.process"> + <title>The PrintLn listener process</title> + <mediaobject><imageobject><imagedata align="center" fileref="images/process.ab.png"/></imageobject></mediaobject> + </figure> + <programlisting>ClientProcessDefinition processDefinition = ProcessFactory.build() + .activity("a").initial().behaviour(new AutomaticActivity()) + <emphasis role="bold">.event("end") + .listener(new PrintLn("leaving a")) + .listener(new PrintLn("second message while leaving a"))</emphasis> + .transition().to("b") + <emphasis role="bold">.listener(new PrintLn("taking transition"))</emphasis> + .activity("b").behaviour(new WaitState()) + .event("start") + <emphasis role="bold">.listener(new PrintLn("entering b"))</emphasis> +.done();</programlisting> + <para>The first event shows how to register multiple listeners to the same + event. They will be notified in the order as they are specified. + </para> + <para>Then, on the transition, there is only one type of event. So in that case, + the event type must not be specified and the listeners can be added directly on + the transition. + </para> + <para>A listeners will be called each time an execution fires the event to + which the listener is subscribed. The execution will be provided in the activity + interface as a parameter and can be used by listeners except for the methods that + control the propagation of execution. + </para> + </section> + + <!-- ### EVENT PROPAGATION ############################################## --> + <section> + <title>Event propagation</title> + <para>Events are by default propagated to enclosing process elements. The motivation + is to allow for listeners on process definitions or composite activities that get executed + for all events that occur within that process element. For example this feature + allows to register an event listener on a process definition or a composite activity on + <literal>end</literal> events. Such action will be executed if that activity is + left. And if that event listener is registered on a composite activity, it will also be executed + for all activities that are left within that composite activity. + </para> + <para>To show this clearly, we'll create a <literal>DisplaySource</literal> event listener + that will print the message <literal>leaving</literal> and the source of the event + to the console. + </para> + <programlisting>public class <emphasis role="bold">DisplaySource</emphasis> implements EventListener { + + public void execute(EventListenerExecution execution) { + <emphasis role="bold">System.out.println("leaving "+execution.getEventSource());</emphasis> + } +}</programlisting> + <para>Note that the purpose of event listeners is not to be visible, that's why the event listener + itself should not be displayed in the diagram. A <literal>DisplaySource</literal> event listener + will be added as a listener to the event <literal>end</literal> on the composite activity. + </para> + <para>The next process shows how the <literal>DisplaySource</literal> event listener is registered + as a listener to to the 'end' event on the <literal>composite</literal> activity:</para> + <figure id="process.propagate"> + <title>A process with an invisible event listener on a end event on a composite activity.</title> + <mediaobject><imageobject><imagedata align="center" fileref="images/process.propagate.png"/></imageobject></mediaobject> + </figure> + <programlisting>TODO update code snippet</programlisting> + <para>Next we'll start an execution.</para> + <programlisting>ClientExecution execution = processDefinition.startProcessInstance();</programlisting> + <para>After starting a new execution, the execution will be in activity <literal>a</literal> as + that is the initial activity. No activities have been left so no message is logged. Next a signal + will be given to the execution, causing it to take the transition from <literal>a</literal> + to <literal>b</literal>. + </para> + <programlisting>execution.signal();</programlisting> + <para>When the signal method returns, the execution will have taken the transition and + the <literal>end</literal> event will be fired on activity <literal>a</literal>. That + event will be propagated to the + composite activity and to the process definition. Since our <literal>DisplaySource</literal> + event listener is placed + on the <literal>composite</literal> activity, it will receive the event and print the following + message on the console: + </para> + <programlisting>leaving activity(a)</programlisting> + <para>Another</para> + <programlisting>execution.signal();</programlisting> + <para>will take the transition from b to c. That will fire two activity-leave events. One on + activity b and one on activity composite. So the following lines will be appended to the console + output:</para> + <programlisting>leaving activity(b) +leaving activity(composite)</programlisting> + <para>Event propagation is build on the hierarchical composition structure of the process + definition. The top level element is always the process definition. The process + definition contains a list of activities. Each activity can be a leaf activity or it can be a + composite activity, which means that it contains a list of nested activities. Nested activities + can be used for e.g. super states or composite activities in nested process languages like BPEL. + </para> + <para>So the even model also works similarly for composite activities as it did for the process + definition above. Suppose that 'Phase one' models + a super state as in state machines. Then event propagation allows to subscribe to all events + within that super state. The idea is that the hierarchical composition corresponds to + diagram representation. If an element 'e' is drawn inside another element 'p', then p + is the parent of e. A process definition has a set of top level activities. Every activity can have + a set of nested activities. The parent of a transition is considered as the first common + parent for it's source and destination. + </para> + <para>If an event listener is not interested in propagated events, propagation can be disabled + with <literal>propagationDisabled()</literal> while building the process with the + <literal>ProcessFactory</literal>. The next process is the same process + as above except that propagated events will be disabled on the event listener. The graph diagram + remains the same. + </para> + <figure id="process.propagate.propagation.disabled"> + <title>A process with an event listener to 'end' events with propagation disabled.</title> + <mediaobject><imageobject><imagedata align="center" fileref="images/process.propagate.png"/></imageobject></mediaobject> + </figure> + <para>Building the process with the process factory: + </para> + <programlisting>TODO update code snippet</programlisting> + <para>So when the first signal is given for this process, again the <literal>end</literal> + event will be fired on activity <literal>a</literal>, but now the event listener on the composite + activity will not be executed cause + propagated events have been disabled. Disabling propagation is a property on the individual + event listener and doesn't influence the other listeners. The event will always be fired and + propagated over the whole parent hierarchy. + </para> + <programlisting>ClientExecution execution = processDefinition.startProcessInstance();</programlisting> + <para>The first signal will take the process from <literal>a</literal> to + <literal>b</literal>. No messages will be printed to the console. + </para> + <programlisting>execution.signal();</programlisting> + <para>Next, the second signal will take the transition from b to c. + </para> + <programlisting>execution.signal()</programlisting> + <para>Again two <literal>end</literal> + events are fired just like above on activities <literal>b</literal> and <literal>composite</literal> + respectively. The first event + is the <literal>end</literal> event on activity <literal>b</literal>. That will be propagated + to the <literal>composite</literal> activity. So the event + listener will not be executed for this event cause it has propagation disabled. But the + event listener will be executed for the <literal>end</literal> event on the + <literal>composite</literal> activity. That is not + propagated, but fired directly on the <literal>composite</literal> activity. So the event + listener will now be executed + only once for the composite activity as shown in the following console output: + </para> + <programlisting>leaving activity(composite)</programlisting> + </section> + +</chapter> Deleted: jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch05-ProcessAnatomy.xml =================================================================== --- jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch05-ProcessAnatomy.xml 2009-05-06 12:55:13 UTC (rev 4748) +++ jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch05-ProcessAnatomy.xml 2009-05-06 14:03:44 UTC (rev 4749) @@ -1,62 +0,0 @@ -<chapter id="processanatomy"> - <title>Process anatomy</title> - - <para>Above we already touched briefly on the two main process constructs: - Activities, transitions and activity composition. This chapter explores in full - all the possibilities of the process definition structures. - </para> - - <para>There are basically two forms of process languages: graph based and composite - process languages. First of all, the process supports both. Even graph based execution - and activity composition can be used in combination to implement something like UML super states. - Furthermore, automatic functional activities can be implemented so that they can be - used with transitions as well as with activity composition. - </para> - - <figure id="process.anatomy"> - <title>UML class diagram of the logical process structure</title> - <mediaobject><imageobject><imagedata align="center" fileref="images/process.anatomy.classes.png"/></imageobject></mediaobject> - </figure> - - <para>Next we'll show a series of example diagram structures that can be formed - with the PVM process model. - </para> - - <figure id="transition"> - <title>Any two activities can be connected with a transition.</title> - <mediaobject><imageobject><imagedata align="center" fileref="images/transition.png"/></imageobject></mediaobject> - </figure> - - <figure id="self.transition"> - <title>A self transition.</title> - <mediaobject><imageobject><imagedata align="center" fileref="images/self.transition.png"/></imageobject></mediaobject> - </figure> - <figure id="composite.activity"> - <title>Composite activity is a list of nested activities.</title> - <mediaobject><imageobject><imagedata align="center" fileref="images/composite.activity.png"/></imageobject></mediaobject> - </figure> - <figure id="transition.into.composite"> - <title>Transition to a activity inside a composite.</title> - <mediaobject><imageobject><imagedata align="center" fileref="images/transition.into.composite.png"/></imageobject></mediaobject> - </figure> - <figure id="transition.out.of.composite"> - <title>Transition from a activity inside a composite to a activity outside the composite.</title> - <mediaobject><imageobject><imagedata align="center" fileref="images/transition.out.of.composite.png"/></imageobject></mediaobject> - </figure> - <figure id="transition.inheritence"> - <title>Transition of composite activities are inherited. The activity inside can take the transition of the composite activity.</title> - <mediaobject><imageobject><imagedata align="center" fileref="images/transition.inheritence.png"/></imageobject></mediaobject> - </figure> - <figure id="transition.to.outer"> - <title>Transition from a activity to an outer composite.</title> - <mediaobject><imageobject><imagedata align="center" fileref="images/transition.to.outer.png"/></imageobject></mediaobject> - </figure> - <figure id="transition.to.inner"> - <title>Transition from a composite activity to an inner composed activity.</title> - <mediaobject><imageobject><imagedata align="center" fileref="images/transition.to.inner.png"/></imageobject></mediaobject> - </figure> - <figure id="initial.in.composite"> - <title>An initial activity inside a composite activity.</title> - <mediaobject><imageobject><imagedata align="center" fileref="images/initial.in.composite.png"/></imageobject></mediaobject> - </figure> -</chapter> \ No newline at end of file Deleted: jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch06-ImplementingAdvancedActivities.xml =================================================================== --- jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch06-ImplementingAdvancedActivities.xml 2009-05-06 12:55:13 UTC (rev 4748) +++ jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch06-ImplementingAdvancedActivities.xml 2009-05-06 14:03:44 UTC (rev 4749) @@ -1,393 +0,0 @@ -<chapter id="advancedgraphexecution"> - <title>Advanced graph execution</title> - - <!-- ### LOOPS ########################################################## --> - <section> - <title>Loops</title> - <para>Activities can implement loops based on transitions or on activity composition. - Loops can contain wait states. - </para> - <para>To support high numbers of automatic loop executions, the Process Virtual Machine - tranformed the propagation of execution from tail recursion to a while loop. - </para> - </section> - - <!-- ### SUB PROCESSES ################################################## --> - <section> - <title>Sub processes</title> - <para>TODO: sub processes</para> - </section> - - <!-- ### DEFAULT PROCEED BEHAVIOUR ###################################### --> - <section id="implicitproceedbehaviour"> - <title>Implicit proceed behaviour</title> - <para>When an <literal>Activity</literal> is used as activity behaviour, it can - explicitely propagate the execution with following methods: - </para> - <itemizedlist> - <listitem><literal>waitForSignal()</literal></listitem> - <listitem><literal>take(Transition)</literal></listitem> - <listitem><literal>end(*)</literal></listitem> - <listitem><literal>execute(Activity)</literal></listitem> - <listitem><literal>createExecution(*)</literal></listitem> - </itemizedlist> - <para>When <literal>Activity</literal> implementations used for activity behviour - don't call any of the following execution propagation methods, then, after - the activity is executed, the execution will apply the implicit proceed behaviour. - </para> - <para>The implicit proceed behaviour is defined as follows:</para> - <itemizedlist> - <listitem>If the current activity has a default outgoing transition, take it.</listitem> - <listitem>If the current activity has a parent activity, move back to the parent activity.</listitem> - <listitem>Otherwise, end this execution.</listitem> - </itemizedlist> - <para>Process languages can overwrite the implicit proceed behaviour - by overriding the <literal>proceed</literal> method in - <literal>ExecutionImpl</literal>. - </para> - </section> - - <!-- ### FUNCTIONAL ACTIVITIES ################################ --> - <section id="functionalactivities"> - <title>Functional activities</title> - <para>Activities that also can be used as event listeners are called functional - activities. Examples of automatic activities are sending an email, doing a database - update, generating a pdf, calculating an average, etc. All of these are automatic - activities that do not change the execution flow. Here's how such activities can - be implemented: - </para> - <programlisting>public class FunctionalActivity implements Activity, EventListener { - public void execute(ActivityExecution execution) { - perform(execution); - } - public void notify(EventListenerExecution execution) { - perform(execution); - } - void perform(OpenExecution execution) { - ...do functional work... - } - }</programlisting> - <para>The <literal>perform</literal> method takes an <literal>OpenExecution</literal>, - which is the supertype of both <literal>ActivityExecution</literal> and - <literal>EventListenerExecution</literal>. <literal>OpenExecution</literal> - does not allow any of the specific purpose methods, but still - the current state and the process definition can be inspected as well - as the variables, which contain the context information for the process - execution. - </para> - <para>None of these methods actually invoke execution propagation methods. - So after the perform method is completed, the execution will - <link linkend="implicitproceedbehaviour">proceed in the default way</link>. - </para> - </section> - - - <!-- ### EXECUTION AND THREADS ########################################## --> - <section id="executionandthreads"> - <title>Execution and threads</title> - <para>This section explains how the Process Virtual Machine boroughs the thread - from the client to bring an execution from one wait state to another. - </para> - <para>When a client invokes a method (like e.g. the signal method) on an execution, - by default, the Process Virtual Machine will use that thread to progress the execution - until it reached a wait state. Once the next wait state has been reached, the - method returns and the client gets the thread back. This is the default way - for the Process Virtual Machine to operate. Two more levels of asynchonous - execution complement this default behaviour: - <link linkend="asynchronouscontinuations">Asynchronous continuations</link> - and the <link linkend="architecture">asynchronous command service</link>. - </para> - <para>The next process will show the basics concretely. It has three wait states - and four automatic activities. - </para> - <figure id="process.automatic"> - <title>Process with many sequential automatic activities.</title> - <mediaobject><imageobject><imagedata align="center" fileref="images/process.automatic.png"/></imageobject></mediaobject> - </figure> - <para>Here's how to build the process:</para> - <programlisting>ClientProcessDefinition processDefinition = ProcessFactory.build("automatic") - .<emphasis role="bold">activity("wait 1").initial()</emphasis>.behaviour(new <emphasis role="bold">WaitState</emphasis>()) - .transition().to("automatic 1") - .<emphasis role="bold">activity("automatic 1")</emphasis>.behaviour(new <emphasis role="bold">Display("one")</emphasis>) - .transition().to("wait 2") - .<emphasis role="bold">activity("wait 2")</emphasis>.behaviour(new <emphasis role="bold">WaitState</emphasis>()) - .transition().to("automatic 2") - .<emphasis role="bold">activity("automatic 2")</emphasis>.behaviour(new <emphasis role="bold">Display("two")</emphasis>) - .transition().to("automatic 3") - .<emphasis role="bold">activity("automatic 3")</emphasis>.behaviour(new <emphasis role="bold">Display("three")</emphasis>) - .transition().to("automatic 4") - .<emphasis role="bold">activity("automatic 4")</emphasis>.behaviour(new <emphasis role="bold">Display("four")</emphasis>) - .transition().to("wait 3") - .<emphasis role="bold">activity("wait 3")</emphasis>.behaviour(new <emphasis role="bold">WaitState</emphasis>()) -.done();</programlisting> - <para>Let's walk you through one execution of this process. - </para> - <programlisting>ClientExecution execution = processDefinition.startProcessInstance();</programlisting> - <para>Starting a new execution means that the initial activity is executed. So if an automatic - activity is the initial activity, this means that immediately the first unnamed outgoing transition - is taken. This happens all inside of the invocation of <literal>startProcessInstance</literal>. - </para> - <para>In this case however, the initial activity is a wait state. So - the method <literal>startProcessInstance</literal> returns immediately and the execution will be - positioned in the initial activity 'wait 1'. - </para> - <figure id="execution.automatic.wait1"> - <title>A new execution will be positioned in 'wait 1'.</title> - <mediaobject><imageobject><imagedata align="center" fileref="images/execution.automatic.wait1.png"/></imageobject></mediaobject> - </figure> - <para>Then an external trigger is given with the signal method.</para> - <programlisting>execution.signal();</programlisting> - <para>As explained above when <link linkend="externalactivityexample">introducing the WaitState</link>, - that signal will cause the default transition to be taken. The - transition will move the execution to activity <literal>automatic 1</literal> and execute it. - The execute method of the <literal>Display</literal> activity in <literal>automatic 1</literal> - print a line to the console and it will <emphasis role="bold">not</emphasis> call - <literal>execution.waitForSignal()</literal>. Therefore, the execution will proceed by - taking the default transition out of <literal>automatic 1</literal>. At this stage, the - signal method is still blocking. Another way to think about it is that the execution - methods like <literal>signal</literal> will use the thread of the client to interpret - the process definition until a wait state is reached. - </para> - <para>Then the execution arrives in <literal>wait 2</literal> and executes - the <literal>WaitState</literal> activity. That method will invoke - the <literal>execution.waitForSignal()</literal>, which will cause the signal method - to return. That is when the thread is given back to the client that invoked the - <literal>signal</literal> method. - </para> - <para>So when the signal method returns, the execution is positioned in <literal>wait 2</literal>.</para> - <figure id="execution.automatic.wait2"> - <title>One signal brought the execution from 'initial' to 'wait 2'.</title> - <mediaobject><imageobject><imagedata align="center" fileref="images/execution.automatic.wait2.png"/></imageobject></mediaobject> - </figure> - <para>Then the execution is now waiting for an external trigger just as an object - (more precisely an object graph) in memory until the next external trigger is given - with the signal method. - </para> - <programlisting>execution.signal();</programlisting> - <para>This second invocation of signal will take the execution similarly all the - way to <literal>wait 3</literal> before it returns. - </para> - <figure id="automatic.wait3"> - <title>The second signal brought the execution all the way to 'wait 3'.</title> - <mediaobject><imageobject><imagedata align="center" fileref="images/ch04.automatic.wait3.png"/></imageobject></mediaobject> - </figure> - <para>The benefits of using this paradigm is that the same process definition - can be executed in <link linkend="clientexecutionmode">client execution mode</link> - (in-memory without persistence) as well as in <link linkend="persistentexecutionmode"> - persistent execution mode</link>, depending on the application and on the environment. - </para> - <para>When executing a process in persistent mode, this is how you typically want - to bind that process execution to transactions of the database: - </para> - <figure id="transactions.png"> - <title>Transactions over time in persistent execution mode.</title> - <mediaobject><imageobject><imagedata align="center" fileref="images/transactions.png"/></imageobject></mediaobject> - </figure> - <para>In most situations, the computational work that needs to be done as part of - the process after an external trigger (the red pieces) is pretty minimal. Typically - transactions combining the process execution and processing the request from the - UI takes typically less then a second. Whereas the wait state in business processes - typically can span for hours, days or even years. The clue is to clearly distinct - when a wait state starts so that only the computational work done before the start - of that wait state should be included in the transaction. - </para> - <para>Think of - it this way: &quot;When an approval arrives, what are all the automated processing that - needs to be done before the process system needs to wait for another external - trigger?&quot; Unless pdf's need to be generated or mass emails need to be send, - the amount of time that this takes is usually neglectable. That is why in the - default persistent execution mode, the process work is executed in the thread - of the client. - </para> - <para>This reasoning even holds in case of concurrent paths of execution. - When a single path of execution splits into concurrent paths of execution, - the process overhead of calculating that is neglectable. So that is why it - makes sense for a fork or split activity implementation that targets persistent - execution mode to spawn the concurrent paths sequentially in the same thread. - Basically it's all just computational work as part of the same transaction. - This can only be done because the fork/split knows that each concurrent path - of execution will return whenever a wait state is encountered. - </para> - <para>Since this is a difficult concept to grasp, I'll explain it again with other - words. Look at it from the overhead that is produced by the process execution - itself in persistent execution mode. If in a transaction, an execution is given - an external trigger and that causes the execution to split into multiple concurrent - paths of execution. Then the process overhead of calculating this is neglectable. - Also the overhead of the generated SQL is neglectable. And since all the work done - in the concurrent branches must be done inside that single transaction, there is - typically no point in having fork/split implementations spawn the concurrent - paths of execution in multiple threads. - </para> - <para>To make executable processes, developers need to know exactly what the automatic activities - are, what the wait states are and which threads will be allocated to the process execution. - For business analysts that draw the analysis process, things are a bit simpler. For the - activities they draw, they usually know whether it's a human or a system that is responsible. - But they typically don't not how this translates to threads and transactions. - </para> - <para>So for the developer, the first job is to analyse what needs to be executed - within the thread of control of the process and what is outside. Looking for the external - triggers can be a good start to find the wait states in a process, just like verbs and nouns - can be the rule of thumb in building UML class diagrams. - </para> - </section> - - <!-- ### PROCESS CONCURRENCY ############################################ --> - <section> - <title>Process concurrency</title> - <para>To model process concurrency, there is a parent-child tree structure on the - execution. The idea is that the main path of execution is the root of that tree. - The main path of execution is also called the process instance. It is the execution - that is created when starting or creating a new process instance for a given - process definition. - </para> - <para>Now, because the main path of execution is the same object as the - process instance, this keeps the usage simple in case of simple processes - without concurrency. - </para> - <figure id="execution.structure"> - <title>UML class diagram of the basic execution structure</title> - <mediaobject><imageobject><imagedata align="center" fileref="images/class.diagram.process.execution.png"/></imageobject></mediaobject> - </figure> - <para>To establish multiple concurrent paths of execution, activity implementations - like a fork or split can create child executions with method - <literal>ActivityExecution.createExecution</literal>. Activity implementations - like join or merge can stop these concurrent paths of execution by calling - method <literal>stop</literal> on the concurrent execution. - </para> - <para>Only leaf executions can be active. Non-leave executions should be - inactive. This tree structure of executions doesn't enforce a particular type of - concurrency or join behaviour. It's up to the forks or and-splits and to the joins - or and-merges to use the execution tree structure in any way they want to define - the wanted concurrency behaviour. Here you see an example - of concurrent executions. - </para> - <figure id="concurrency"> - <title>Concurrent paths of execution</title> - <mediaobject><imageobject><imagedata align="center" fileref="images/execution.concurrency.png"/></imageobject></mediaobject> - </figure> - <para>There is a billing and a shipping path of execution. In this case, the - flat bar activities represent activities that fork and join. The execution shows a three - executions. The main path of execution is inactive (represented as gray) and the - billing and shipping paths of execution are active and point to the activity - <literal>bill</literal> and <literal>ship</literal> respectively. - </para> - <para>It's up to the activity behaviour implementations how they want to use this - execution structure. Suppose that multiple tasks have to be completed before the - execution is to proceed. The activity behaviour can spawn a series of child executions - for this. Or alternatively, the task component could support task groups that - are associated to one single execution. In that case, the task component becomes - responsible for synchronizing the tasks, thereby moving this responsibility - outside the scope of the execution tree structure. - </para> - </section> - - <!-- ### EXCEPTION HANDLERS ############################################# --> - <section> - <title>Exception handlers</title> - <para>In all the code that is associated to a process - like <literal>Activity</literal>s, <literal>EventListeners</literal> and - <literal>Condition</literal>s, it's possible to associate exception handlers. This - can be thought of as including try-catch blocks in - the method implementations of those implementations. But in order to build more reusable building - blocks for both the delegation classes and the exception handling logic, exception handlers are - added to the core process model. - </para> - <para>An exception handler can be associated to any process element. When an exception - occurs in a delegation class, a matching exception handler will be searched for. If - such an exception handler is found, it will get a chance to handle the exception. - </para> - <para>If an exception handler completes without problems, then the exception is considered - handled and the execution resumes right after the delegation code that was called. For example, - a transition has three actions and the second action throws an exception that is handled - by an exception handler, then - </para> - <para>Writing automatic activities that are exception handler aware is easy. The - default is to proceed anyway. No method needs to be called on the execution. So - if an automatic activity throws an exception that is handled by an exception handler, - the execution will just proceed after that activity. It becomes a big more difficult - for control flow activities. They might have to include try-finally blocks to - invoke the proper methods on the execution before an exception handler gets a - chance to handle the exception. For example, if an activity is a wait state and - an exception occurs, then there is a risk that the thread jumps over the - invocation of <literal>execution.waitForSignal()</literal>, causing the execution - to proceed after the activity. - </para> - <para>TODO: exceptionhandler.isRethrowMasked</para> - <para>TODO: transactional exception handlers</para> - <para>TODO: we never catch errors</para> - </section> - - <!-- ### PROCESS MODIFICATIONS ########################################## --> - <section> - <title>Process modifications</title> - <para>TODO: process modifications</para> - </section> - - <!-- ### LOCKING AND EXECUTION STATE #################################### --> - <section> - <title>Locking and execution state</title> - <para>The state of an execution is either active or locked. An active - execution is either executing or waiting for an external trigger. If an - execution is not in <literal>STATE_ACTIVE</literal>, then it is locked. - A locked execution is read only and cannot receive any external triggers. - </para> - <para>When a new execution is created, it is in STATE_ACTIVE. To change - the state to a locked state, use lock(String). Some STATE_* constants - are provided that represent the most commonly used locked states. But - the state '...' in the picture indicates that any string can be provided - as the state in the lock method. - </para> - <figure id="execution.states"> - <title>States of an execution</title> - <mediaobject><imageobject><imagedata align="center" fileref="images/ch04.execution.states.png"/></imageobject></mediaobject> - </figure> - <para>If an execution is locked, methods that change the execution will - throw a PvmException and the message will reference the actual locking state. - Firing events, updating variables, updating priority and adding comments - are not considered to change an execution. Also creation and removal of child - executions are unchecked, which means that those methods can be invoked by - external API clients and activity behaviour methods, even while the execution - is in a locked state. - </para> - <para>Make sure that comparisons between getState() and the STATE_* constants - are done with .equals and not with '==' because if executions are loaded - from persistent storage, a new string is created instead of the constants. - </para> - <para>An execution implementation will be locked: - </para> - <itemizedlist> - <listitem>When it is ended</listitem> - <listitem>When it is suspended</listitem> - <listitem>During asynchronous continuations</listitem> - </itemizedlist> - <para>Furthermore, locking can be used by Activity implementations to make - executions read only during wait states hen responsibility for the execution is - transferred to an external entity such as: - </para> - <itemizedlist> - <listitem>A human task</listitem> - <listitem>A service invocation</listitem> - <listitem>A wait state that ends when a scanner detects that a file appears</listitem> - </itemizedlist> - <para>In these situations the strategy is that the external entity should get - full control over the execution because it wants to control what is allowed - and what not. To get that control, they lock the execution so that all interactions - have to go through the external entity. - </para> - <para>One of the main reasons to create external entities is that they can live - on after the execution has already proceeded. For example, in case - of a service invocation, a timer could cause the execution to take the timeout transition. - When the response arrives after the timeout, the service invocation entity should - make sure it doesn't signal the execution. So the service invocation can be - seen as a activity instance (aka activity instance) and is unique for every execution - of the activity. - </para> - <para>External entities themselves are responsible for managing the execution - lock. If the timers and client applications are consequent in addressing the - external entities instead of the execution directly, then locking is in theory - unnecessary. It's up to the activity behaviour implementations whether they want - to take the overhead of locking and unlocking. - </para> - </section> - -</chapter> Copied: jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch06-ProcessAnatomy.xml (from rev 4742, jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch05-ProcessAnatomy.xml) =================================================================== --- jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch06-ProcessAnatomy.xml (rev 0) +++ jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch06-ProcessAnatomy.xml 2009-05-06 14:03:44 UTC (rev 4749) @@ -0,0 +1,62 @@ +<chapter id="processanatomy"> + <title>Process anatomy</title> + + <para>Above we already touched briefly on the two main process constructs: + Activities, transitions and activity composition. This chapter explores in full + all the possibilities of the process definition structures. + </para> + + <para>There are basically two forms of process languages: graph based and composite + process languages. First of all, the process supports both. Even graph based execution + and activity composition can be used in combination to implement something like UML super states. + Furthermore, automatic functional activities can be implemented so that they can be + used with transitions as well as with activity composition. + </para> + + <figure id="process.anatomy"> + <title>UML class diagram of the logical process structure</title> + <mediaobject><imageobject><imagedata align="center" fileref="images/process.anatomy.classes.png"/></imageobject></mediaobject> + </figure> + + <para>Next we'll show a series of example diagram structures that can be formed + with the PVM process model. + </para> + + <figure id="transition"> + <title>Any two activities can be connected with a transition.</title> + <mediaobject><imageobject><imagedata align="center" fileref="images/transition.png"/></imageobject></mediaobject> + </figure> + + <figure id="self.transition"> + <title>A self transition.</title> + <mediaobject><imageobject><imagedata align="center" fileref="images/self.transition.png"/></imageobject></mediaobject> + </figure> + <figure id="composite.activity"> + <title>Composite activity is a list of nested activities.</title> + <mediaobject><imageobject><imagedata align="center" fileref="images/composite.activity.png"/></imageobject></mediaobject> + </figure> + <figure id="transition.into.composite"> + <title>Transition to a activity inside a composite.</title> + <mediaobject><imageobject><imagedata align="center" fileref="images/transition.into.composite.png"/></imageobject></mediaobject> + </figure> + <figure id="transition.out.of.composite"> + <title>Transition from a activity inside a composite to a activity outside the composite.</title> + <mediaobject><imageobject><imagedata align="center" fileref="images/transition.out.of.composite.png"/></imageobject></mediaobject> + </figure> + <figure id="transition.inheritence"> + <title>Transition of composite activities are inherited. The activity inside can take the transition of the composite activity.</title> + <mediaobject><imageobject><imagedata align="center" fileref="images/transition.inheritence.png"/></imageobject></mediaobject> + </figure> + <figure id="transition.to.outer"> + <title>Transition from a activity to an outer composite.</title> + <mediaobject><imageobject><imagedata align="center" fileref="images/transition.to.outer.png"/></imageobject></mediaobject> + </figure> + <figure id="transition.to.inner"> + <title>Transition from a composite activity to an inner composed activity.</title> + <mediaobject><imageobject><imagedata align="center" fileref="images/transition.to.inner.png"/></imageobject></mediaobject> + </figure> + <figure id="initial.in.composite"> + <title>An initial activity inside a composite activity.</title> + <mediaobject><imageobject><imagedata align="center" fileref="images/initial.in.composite.png"/></imageobject></mediaobject> + </figure> +</chapter> \ No newline at end of file Copied: jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch07-ImplementingAdvancedActivities.xml (from rev 4742, jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch06-ImplementingAdvancedActivities.xml) =================================================================== --- jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch07-ImplementingAdvancedActivities.xml (rev 0) +++ jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/ch07-ImplementingAdvancedActivities.xml 2009-05-06 14:03:44 UTC (rev 4749) @@ -0,0 +1,393 @@ +<chapter id="advancedgraphexecution"> + <title>Advanced graph execution</title> + + <!-- ### LOOPS ########################################################## --> + <section> + <title>Loops</title> + <para>Activities can implement loops based on transitions or on activity composition. + Loops can contain wait states. + </para> + <para>To support high numbers of automatic loop executions, the Process Virtual Machine + tranformed the propagation of execution from tail recursion to a while loop. + </para> + </section> + + <!-- ### SUB PROCESSES ################################################## --> + <section> + <title>Sub processes</title> + <para>TODO: sub processes</para> + </section> + + <!-- ### DEFAULT PROCEED BEHAVIOUR ###################################### --> + <section id="implicitproceedbehaviour"> + <title>Implicit proceed behaviour</title> + <para>When an <literal>Activity</literal> is used as activity behaviour, it can + explicitely propagate the execution with following methods: + </para> + <itemizedlist> + <listitem><literal>waitForSignal()</literal></listitem> + <listitem><literal>take(Transition)</literal></listitem> + <listitem><literal>end(*)</literal></listitem> + <listitem><literal>execute(Activity)</literal></listitem> + <listitem><literal>createExecution(*)</literal></listitem> + </itemizedlist> + <para>When <literal>Activity</literal> implementations used for activity behviour + don't call any of the following execution propagation methods, then, after + the activity is executed, the execution will apply the implicit proceed behaviour. + </para> + <para>The implicit proceed behaviour is defined as follows:</para> + <itemizedlist> + <listitem>If the current activity has a default outgoing transition, take it.</listitem> + <listitem>If the current activity has a parent activity, move back to the parent activity.</listitem> + <listitem>Otherwise, end this execution.</listitem> + </itemizedlist> + <para>Process languages can overwrite the implicit proceed behaviour + by overriding the <literal>proceed</literal> method in + <literal>ExecutionImpl</literal>. + </para> + </section> + + <!-- ### FUNCTIONAL ACTIVITIES ################################ --> + <section id="functionalactivities"> + <title>Functional activities</title> + <para>Activities that also can be used as event listeners are called functional + activities. Examples of automatic activities are sending an email, doing a database + update, generating a pdf, calculating an average, etc. All of these are automatic + activities that do not change the execution flow. Here's how such activities can + be implemented: + </para> + <programlisting>public class FunctionalActivity implements Activity, EventListener { + public void execute(ActivityExecution execution) { + perform(execution); + } + public void notify(EventListenerExecution execution) { + perform(execution); + } + void perform(OpenExecution execution) { + ...do functional work... + } + }</programlisting> + <para>The <literal>perform</literal> method takes an <literal>OpenExecution</literal>, + which is the supertype of both <literal>ActivityExecution</literal> and + <literal>EventListenerExecution</literal>. <literal>OpenExecution</literal> + does not allow any of the specific purpose methods, but still + the current state and the process definition can be inspected as well + as the variables, which contain the context information for the process + execution. + </para> + <para>None of these methods actually invoke execution propagation methods. + So after the perform method is completed, the execution will + <link linkend="implicitproceedbehaviour">proceed in the default way</link>. + </para> + </section> + + + <!-- ### EXECUTION AND THREADS ########################################## --> + <section id="executionandthreads"> + <title>Execution and threads</title> + <para>This section explains how the Process Virtual Machine boroughs the thread + from the client to bring an execution from one wait state to another. + </para> + <para>When a client invokes a method (like e.g. the signal method) on an execution, + by default, the Process Virtual Machine will use that thread to progress the execution + until it reached a wait state. Once the next wait state has been reached, the + method returns and the client gets the thread back. This is the default way + for the Process Virtual Machine to operate. Two more levels of asynchonous + execution complement this default behaviour: + <link linkend="asynchronouscontinuations">Asynchronous continuations</link> + and the <link linkend="architecture">asynchronous command service</link>. + </para> + <para>The next process will show the basics concretely. It has three wait states + and four automatic activities. + </para> + <figure id="process.automatic"> + <title>Process with many sequential automatic activities.</title> + <mediaobject><imageobject><imagedata align="center" fileref="images/process.automatic.png"/></imageobject></mediaobject> + </figure> + <para>Here's how to build the process:</para> + <programlisting>ClientProcessDefinition processDefinition = ProcessFactory.build("automatic") + .<emphasis role="bold">activity("wait 1").initial()</emphasis>.behaviour(new <emphasis role="bold">WaitState</emphasis>()) + .transition().to("automatic 1") + .<emphasis role="bold">activity("automatic 1")</emphasis>.behaviour(new <emphasis role="bold">Display("one")</emphasis>) + .transition().to("wait 2") + .<emphasis role="bold">activity("wait 2")</emphasis>.behaviour(new <emphasis role="bold">WaitState</emphasis>()) + .transition().to("automatic 2") + .<emphasis role="bold">activity("automatic 2")</emphasis>.behaviour(new <emphasis role="bold">Display("two")</emphasis>) + .transition().to("automatic 3") + .<emphasis role="bold">activity("automatic 3")</emphasis>.behaviour(new <emphasis role="bold">Display("three")</emphasis>) + .transition().to("automatic 4") + .<emphasis role="bold">activity("automatic 4")</emphasis>.behaviour(new <emphasis role="bold">Display("four")</emphasis>) + .transition().to("wait 3") + .<emphasis role="bold">activity("wait 3")</emphasis>.behaviour(new <emphasis role="bold">WaitState</emphasis>()) +.done();</programlisting> + <para>Let's walk you through one execution of this process. + </para> + <programlisting>ClientExecution execution = processDefinition.startProcessInstance();</programlisting> + <para>Starting a new execution means that the initial activity is executed. So if an automatic + activity is the initial activity, this means that immediately the first unnamed outgoing transition + is taken. This happens all inside of the invocation of <literal>startProcessInstance</literal>. + </para> + <para>In this case however, the initial activity is a wait state. So + the method <literal>startProcessInstance</literal> returns immediately and the execution will be + positioned in the initial activity 'wait 1'. + </para> + <figure id="execution.automatic.wait1"> + <title>A new execution will be positioned in 'wait 1'.</title> + <mediaobject><imageobject><imagedata align="center" fileref="images/execution.automatic.wait1.png"/></imageobject></mediaobject> + </figure> + <para>Then an external trigger is given with the signal method.</para> + <programlisting>execution.signal();</programlisting> + <para>As explained above when <link linkend="externalactivityexample">introducing the WaitState</link>, + that signal will cause the default transition to be taken. The + transition will move the execution to activity <literal>automatic 1</literal> and execute it. + The execute method of the <literal>Display</literal> activity in <literal>automatic 1</literal> + print a line to the console and it will <emphasis role="bold">not</emphasis> call + <literal>execution.waitForSignal()</literal>. Therefore, the execution will proceed by + taking the default transition out of <literal>automatic 1</literal>. At this stage, the + signal method is still blocking. Another way to think about it is that the execution + methods like <literal>signal</literal> will use the thread of the client to interpret + the process definition until a wait state is reached. + </para> + <para>Then the execution arrives in <literal>wait 2</literal> and executes + the <literal>WaitState</literal> activity. That method will invoke + the <literal>execution.waitForSignal()</literal>, which will cause the signal method + to return. That is when the thread is given back to the client that invoked the + <literal>signal</literal> method. + </para> + <para>So when the signal method returns, the execution is positioned in <literal>wait 2</literal>.</para> + <figure id="execution.automatic.wait2"> + <title>One signal brought the execution from 'initial' to 'wait 2'.</title> + <mediaobject><imageobject><imagedata align="center" fileref="images/execution.automatic.wait2.png"/></imageobject></mediaobject> + </figure> + <para>Then the execution is now waiting for an external trigger just as an object + (more precisely an object graph) in memory until the next external trigger is given + with the signal method. + </para> + <programlisting>execution.signal();</programlisting> + <para>This second invocation of signal will take the execution similarly all the + way to <literal>wait 3</literal> before it returns. + </para> + <figure id="automatic.wait3"> + <title>The second signal brought the execution all the way to 'wait 3'.</title> + <mediaobject><imageobject><imagedata align="center" fileref="images/ch04.automatic.wait3.png"/></imageobject></mediaobject> + </figure> + <para>The benefits of using this paradigm is that the same process definition + can be executed in <link linkend="clientexecutionmode">client execution mode</link> + (in-memory without persistence) as well as in <link linkend="persistentexecutionmode"> + persistent execution mode</link>, depending on the application and on the environment. + </para> + <para>When executing a process in persistent mode, this is how you typically want + to bind that process execution to transactions of the database: + </para> + <figure id="transactions.png"> + <title>Transactions over time in persistent execution mode.</title> + <mediaobject><imageobject><imagedata align="center" fileref="images/transactions.png"/></imageobject></mediaobject> + </figure> + <para>In most situations, the computational work that needs to be done as part of + the process after an external trigger (the red pieces) is pretty minimal. Typically + transactions combining the process execution and processing the request from the + UI takes typically less then a second. Whereas the wait state in business processes + typically can span for hours, days or even years. The clue is to clearly distinct + when a wait state starts so that only the computational work done before the start + of that wait state should be included in the transaction. + </para> + <para>Think of + it this way: &quot;When an approval arrives, what are all the automated processing that + needs to be done before the process system needs to wait for another external + trigger?&quot; Unless pdf's need to be generated or mass emails need to be send, + the amount of time that this takes is usually neglectable. That is why in the + default persistent execution mode, the process work is executed in the thread + of the client. + </para> + <para>This reasoning even holds in case of concurrent paths of execution. + When a single path of execution splits into concurrent paths of execution, + the process overhead of calculating that is neglectable. So that is why it + makes sense for a fork or split activity implementation that targets persistent + execution mode to spawn the concurrent paths sequentially in the same thread. + Basically it's all just computational work as part of the same transaction. + This can only be done because the fork/split knows that each concurrent path + of execution will return whenever a wait state is encountered. + </para> + <para>Since this is a difficult concept to grasp, I'll explain it again with other + words. Look at it from the overhead that is produced by the process execution + itself in persistent execution mode. If in a transaction, an execution is given + an external trigger and that causes the execution to split into multiple concurrent + paths of execution. Then the process overhead of calculating this is neglectable. + Also the overhead of the generated SQL is neglectable. And since all the work done + in the concurrent branches must be done inside that single transaction, there is + typically no point in having fork/split implementations spawn the concurrent + paths of execution in multiple threads. + </para> + <para>To make executable processes, developers need to know exactly what the automatic activities + are, what the wait states are and which threads will be allocated to the process execution. + For business analysts that draw the analysis process, things are a bit simpler. For the + activities they draw, they usually know whether it's a human or a system that is responsible. + But they typically don't not how this translates to threads and transactions. + </para> + <para>So for the developer, the first job is to analyse what needs to be executed + within the thread of control of the process and what is outside. Looking for the external + triggers can be a good start to find the wait states in a process, just like verbs and nouns + can be the rule of thumb in building UML class diagrams. + </para> + </section> + + <!-- ### PROCESS CONCURRENCY ############################################ --> + <section> + <title>Process concurrency</title> + <para>To model process concurrency, there is a parent-child tree structure on the + execution. The idea is that the main path of execution is the root of that tree. + The main path of execution is also called the process instance. It is the execution + that is created when starting or creating a new process instance for a given + process definition. + </para> + <para>Now, because the main path of execution is the same object as the + process instance, this keeps the usage simple in case of simple processes + without concurrency. + </para> + <figure id="execution.structure"> + <title>UML class diagram of the basic execution structure</title> + <mediaobject><imageobject><imagedata align="center" fileref="images/class.diagram.process.execution.png"/></imageobject></mediaobject> + </figure> + <para>To establish multiple concurrent paths of execution, activity implementations + like a fork or split can create child executions with method + <literal>ActivityExecution.createExecution</literal>. Activity implementations + like join or merge can stop these concurrent paths of execution by calling + method <literal>stop</literal> on the concurrent execution. + </para> + <para>Only leaf executions can be active. Non-leave executions should be + inactive. This tree structure of executions doesn't enforce a particular type of + concurrency or join behaviour. It's up to the forks or and-splits and to the joins + or and-merges to use the execution tree structure in any way they want to define + the wanted concurrency behaviour. Here you see an example + of concurrent executions. + </para> + <figure id="concurrency"> + <title>Concurrent paths of execution</title> + <mediaobject><imageobject><imagedata align="center" fileref="images/execution.concurrency.png"/></imageobject></mediaobject> + </figure> + <para>There is a billing and a shipping path of execution. In this case, the + flat bar activities represent activities that fork and join. The execution shows a three + executions. The main path of execution is inactive (represented as gray) and the + billing and shipping paths of execution are active and point to the activity + <literal>bill</literal> and <literal>ship</literal> respectively. + </para> + <para>It's up to the activity behaviour implementations how they want to use this + execution structure. Suppose that multiple tasks have to be completed before the + execution is to proceed. The activity behaviour can spawn a series of child executions + for this. Or alternatively, the task component could support task groups that + are associated to one single execution. In that case, the task component becomes + responsible for synchronizing the tasks, thereby moving this responsibility + outside the scope of the execution tree structure. + </para> + </section> + + <!-- ### EXCEPTION HANDLERS ############################################# --> + <section> + <title>Exception handlers</title> + <para>In all the code that is associated to a process + like <literal>Activity</literal>s, <literal>EventListeners</literal> and + <literal>Condition</literal>s, it's possible to associate exception handlers. This + can be thought of as including try-catch blocks in + the method implementations of those implementations. But in order to build more reusable building + blocks for both the delegation classes and the exception handling logic, exception handlers are + added to the core process model. + </para> + <para>An exception handler can be associated to any process element. When an exception + occurs in a delegation class, a matching exception handler will be searched for. If + such an exception handler is found, it will get a chance to handle the exception. + </para> + <para>If an exception handler completes without problems, then the exception is considered + handled and the execution resumes right after the delegation code that was called. For example, + a transition has three actions and the second action throws an exception that is handled + by an exception handler, then + </para> + <para>Writing automatic activities that are exception handler aware is easy. The + default is to proceed anyway. No method needs to be called on the execution. So + if an automatic activity throws an exception that is handled by an exception handler, + the execution will just proceed after that activity. It becomes a big more difficult + for control flow activities. They might have to include try-finally blocks to + invoke the proper methods on the execution before an exception handler gets a + chance to handle the exception. For example, if an activity is a wait state and + an exception occurs, then there is a risk that the thread jumps over the + invocation of <literal>execution.waitForSignal()</literal>, causing the execution + to proceed after the activity. + </para> + <para>TODO: exceptionhandler.isRethrowMasked</para> + <para>TODO: transactional exception handlers</para> + <para>TODO: we never catch errors</para> + </section> + + <!-- ### PROCESS MODIFICATIONS ########################################## --> + <section> + <title>Process modifications</title> + <para>TODO: process modifications</para> + </section> + + <!-- ### LOCKING AND EXECUTION STATE #################################### --> + <section> + <title>Locking and execution state</title> + <para>The state of an execution is either active or locked. An active + execution is either executing or waiting for an external trigger. If an + execution is not in <literal>STATE_ACTIVE</literal>, then it is locked. + A locked execution is read only and cannot receive any external triggers. + </para> + <para>When a new execution is created, it is in STATE_ACTIVE. To change + the state to a locked state, use lock(String). Some STATE_* constants + are provided that represent the most commonly used locked states. But + the state '...' in the picture indicates that any string can be provided + as the state in the lock method. + </para> + <figure id="execution.states"> + <title>States of an execution</title> + <mediaobject><imageobject><imagedata align="center" fileref="images/ch04.execution.states.png"/></imageobject></mediaobject> + </figure> + <para>If an execution is locked, methods that change the execution will + throw a PvmException and the message will reference the actual locking state. + Firing events, updating variables, updating priority and adding comments + are not considered to change an execution. Also creation and removal of child + executions are unchecked, which means that those methods can be invoked by + external API clients and activity behaviour methods, even while the execution + is in a locked state. + </para> + <para>Make sure that comparisons between getState() and the STATE_* constants + are done with .equals and not with '==' because if executions are loaded + from persistent storage, a new string is created instead of the constants. + </para> + <para>An execution implementation will be locked: + </para> + <itemizedlist> + <listitem>When it is ended</listitem> + <listitem>When it is suspended</listitem> + <listitem>During asynchronous continuations</listitem> + </itemizedlist> + <para>Furthermore, locking can be used by Activity implementations to make + executions read only during wait states hen responsibility for the execution is + transferred to an external entity such as: + </para> + <itemizedlist> + <listitem>A human task</listitem> + <listitem>A service invocation</listitem> + <listitem>A wait state that ends when a scanner detects that a file appears</listitem> + </itemizedlist> + <para>In these situations the strategy is that the external entity should get + full control over the execution because it wants to control what is allowed + and what not. To get that control, they lock the execution so that all interactions + have to go through the external entity. + </para> + <para>One of the main reasons to create external entities is that they can live + on after the execution has already proceeded. For example, in case + of a service invocation, a timer could cause the execution to take the timeout transition. + When the response arrives after the timeout, the service invocation entity should + make sure it doesn't signal the execution. So the service invocation can be + seen as a activity instance (aka activity instance) and is unique for every execution + of the activity. + </para> + <para>External entities themselves are responsible for managing the execution + lock. If the timers and client applications are consequent in addressing the + external entities instead of the execution directly, then locking is in theory + unnecessary. It's up to the activity behaviour implementations whether they want + to take the overhead of locking and unlocking. + </para> + </section> + +</chapter> Modified: jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/chxx-ExecutionModes.xml =================================================================== --- jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/chxx-ExecutionModes.xml 2009-05-06 12:55:13 UTC (rev 4748) +++ jbpm4/trunk/modules/devguide/src/main/docbook/en/modules/chxx-ExecutionModes.xml 2009-05-06 14:03:44 UTC (rev 4749) @@ -102,7 +102,7 @@ like this: </para> <literal><emphasis role="bold">environment.cfg.xml</emphasis>:</literal> - <programlisting>&lt;jbpm-configuration xmlns=&quot;http://jbpm.org/xsd/cfg&quot;&gt; + <programlisting>&lt;jbpm-configuration&gt; &lt;process-engine-context&gt; Modified: jbpm4/trunk/modules/distro/src/main/files/jboss/config.common/deploy/jbpm/jbpm-service.sar/jbpm.cfg.xml =================================================================== --- jbpm4/trunk/modules/distro/src/main/files/jboss/config.common/deploy/jbpm/jbpm-service.sar/jbpm.cfg.xml 2009-05-06 12:55:13 UTC (rev 4748) +++ jbpm4/trunk/modules/distro/src/main/files/jboss/config.common/deploy/jbpm/jbpm-service.sar/jbpm.cfg.xml 2009-05-06 14:03:44 UTC (rev 4749) @@ -1,6 +1,6 @@ <?xml version="1.0" encoding="UTF-8"?> -<jbpm-configuration xmlns="http://jbpm.org/xsd/cfg"> +<jbpm-configuration> <import resource="jbpm.default.cfg.xml" /> <import resource="jbpm.tx.jta.cfg.xml" /> Copied: jbpm4/trunk/modules/distro/src/main/files/jboss/config.jboss4/deploy/jbpm/jbpm-service.sar/META-INF/jboss-service.xml (from rev 4742, jbpm4/trunk/modules/distro/src/main/deployer/config.jboss4/deploy/jbpm/jbpm-service.sar/META-INF/jboss-service.xml) =================================================================== --- jbpm4/trunk/modules/distro/src/main/files/jboss/config.jboss4/deploy/jbpm/jbpm-service.sar/META-INF/jboss-service.xml (rev 0) +++ jbpm4/trunk/modules/distro/src/main/files/jboss/config.jboss4/deploy/jbpm/jbpm-service.sar/META-INF/jboss-service.xml 2009-05-06 14:03:44 UTC (rev 4749) @@ -0,0 +1,14 @@ +<?xml version="1.0" encoding="UTF-8"?> +<!-- $Id: jboss-service.xml 44143 2006-04-24 18:19:21Z kkhan $ --> + +<!-- ===================================================================== --> +<!-- JBoss Server Configuration --> +<!-- ===================================================================== --> + +<server> + + <mbean code="org.jbpm.integration.jboss4.JBPMDeployer" + name="org.jbpm:service=JBPMDeployer"> + </mbean> + +</server> Property changes on: jbpm4/trunk/modules/distro/src/main/files/jboss/config.jboss4/deploy/jbpm/jbpm-service.sar/META-INF/jboss-service.xml ___________________________________________________________________ Name: svn:mime-type + text/plain Modified: jbpm4/trunk/modules/distro/src/main/files/jboss/jbpm.cfg.integration.tests/jbpm.cfg.xml =================================================================== --- jbpm4/trunk/modules/distro/src/main/files/jboss/jbpm.cfg.integration.tests/jbpm.cfg.xml 2009-05-06 12:55:13 UTC (rev 4748) +++ jbpm4/trunk/modules/distro/src/main/files/jboss/jbpm.cfg.integration.tests/jbpm.cfg.xml 2009-05-06 14:03:44 UTC (rev 4749) @@ -1,12 +1,16 @@ <?xml version="1.0" encoding="UTF-8"?> -<jbpm-configuration xmlns="http://jbpm.org/xsd/cfg"> +<jbpm-configuration> <import resource="jbpm.default.cfg.xml" /> <import resource="jbpm.tx.jta.cfg.xml" /> <import resource="jbpm.jpdl.cfg.xml" /> <import resource="jbpm.identity.cfg.xml" /> + <!-- Job executor is excluded for running the example test cases. + To enable timers and messages in production use, this should be included. + import resource="jbpm.jobexecutor.cfg.xml" / --> + <process-engine-context> <mail-template name="MemoTemplate"> Modified: jbpm4/trunk/modules/distro/src/main/files/jboss/jbpm.cfg.remote.client/jbpm.cfg.xml =================================================================== --- jbpm4/trunk/modules/distro/src/main/files/jboss/jbpm.cfg.remote.client/jbpm.cfg.xml 2009-05-06 12:55:13 UTC (rev 4748) +++ jbpm4/trunk/modules/distro/src/main/files/jboss/jbpm.cfg.remote.client/jbpm.cfg.xml 2009-05-06 14:03:44 UTC (rev 4749) @@ -1,6 +1,6 @@ <?xml version="1.0" encoding="UTF-8"?> -<jbpm-configuration xmlns="http://jbpm.org/xsd/cfg"> +<jbpm-configuration> <import resource="jbpm.jbossremote.cfg.xml" /> Modified: jbpm4/trunk/modules/enterprise/src/test/java/org/jbpm/enterprise/internal/ejb/TimerTest.java =================================================================== --- jbpm4/trunk/modules/enterprise/src/test/java/org/jbpm/enterprise/internal/ejb/TimerTest.java 2009-05-06 12:55:13 UTC (rev 4748) +++ jbpm4/trunk/modules/enterprise/src/test/java/org/jbpm/enterprise/internal/ejb/TimerTest.java 2009-05-06 14:03:44 UTC (rev 4749) @@ -30,7 +30,6 @@ import org.jbpm.api.Execution; import org.jbpm.api.ExecutionService; -import org.jbpm.api.ProcessService; import org.jbpm.api.RepositoryService; import org.jbpm.api.client.ClientProcessDefinition; import org.jbpm.api.cmd.Command; Modified: jbpm4/trunk/modules/enterprise/src/test/java/org/jbpm/test/deployer/DeployerTestServlet.java =================================================================== --- jbpm4/trunk/modules/enterprise/src/test/java/org/jbpm/test/deployer/DeployerTestServlet.java 2009-05-06 12:55:13 UTC (rev 4748) +++ jbpm4/trunk/modules/enterprise/src/test/java/org/jbpm/test/deployer/DeployerTestServlet.java 2009-05-06 14:03:44 UTC (rev 4749) @@ -21,22 +21,22 @@ */ package org.jbpm.test.deployer; -import org.jbpm.api.ProcessDefinition; -import org.jbpm.api.ProcessDefinitionQuery; -import org.jbpm.api.ProcessEngine; -import org.jbpm.api.ProcessService; -import org.jbpm.api.RepositoryService; +import java.io.IOException; +import java.io.PrintWriter; +import javax.naming.InitialContext; +import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; -import javax.servlet.ServletException; -import javax.naming.InitialContext; +import javax.transaction.SystemException; import javax.transaction.UserTransaction; -import javax.transaction.SystemException; -import java.io.IOException; -import java.io.PrintWriter; +import org.jbpm.api.ProcessDefinition; +import org.jbpm.api.ProcessDefinitionQuery; +import org.jbpm.api.ProcessEngine; +import org.jbpm.api.RepositoryService; + /** * @author Heiko.Braun <heiko.braun(a)jboss.com&gt; */ Modified: jbpm4/trunk/modules/examples/src/test/resources/jbpm.cfg.xml =================================================================== --- jbpm4/trunk/modules/examples/src/test/resources/jbpm.cfg.xml 2009-05-06 12:55:13 UTC (rev 4748) +++ jbpm4/trunk/modules/examples/src/test/resources/jbpm.cfg.xml 2009-05-06 14:03:44 UTC (rev 4749) @@ -1,12 +1,16 @@ <?xml version="1.0" encoding="UTF-8"?> -<jbpm-configuration xmlns="http://jbpm.org/xsd/cfg"> +<jbpm-configuration> <import resource="jbpm.default.cfg.xml" /> <import resource="jbpm.tx.hibernate.cfg.xml" /> <import resource="jbpm.jpdl.cfg.xml" /> <import resource="jbpm.identity.cfg.xml" /> + <!-- Job executor is excluded for running the example test cases. + To enable timers and messages in production use, this should be included. + import resource="jbpm.jobexecutor.cfg.xml" / --> + <process-engine-context> <mail-template name="MemoTemplate"> Modified: jbpm4/trunk/modules/jpdl/src/main/resources/jbpm.jpdl.cfg.xml =================================================================== --- jbpm4/trunk/modules/jpdl/src/main/resources/jbpm.jpdl.cfg.xml 2009-05-06 12:55:13 UTC (rev 4748) +++ jbpm4/trunk/modules/jpdl/src/main/resources/jbpm.jpdl.cfg.xml 2009-05-06 14:03:44 UTC (rev 4749) @@ -1,6 +1,6 @@ <?xml version="1.0" encoding="UTF-8"?> -<jbpm-configuration xmlns="http://jbpm.org/xsd/cfg"> +<jbpm-configuration> <process-engine-context> Modified: jbpm4/trunk/modules/jpdl/src/test/resources/jbpm.cfg.xml =================================================================== --- jbpm4/trunk/modules/jpdl/src/test/resources/jbpm.cfg.xml 2009-05-06 12:55:13 UTC (rev 4748) +++ jbpm4/trunk/modules/jpdl/src/test/resources/jbpm.cfg.xml 2009-05-06 14:03:44 UTC (rev 4749) @@ -1,6 +1,6 @@ <?xml version="1.0" encoding="UTF-8"?> -<jbpm-configuration xmlns="http://jbpm.org/xsd/cfg"> +<jbpm-configuration> <import resource="jbpm.default.cfg.xml" /> <import resource="jbpm.tx.hibernate.cfg.xml" /> Modified: jbpm4/trunk/modules/pvm/src/main/java/org/jbpm/pvm/internal/env/JbpmConfigurationParser.java =================================================================== --- jbpm4/trunk/modules/pvm/src/main/java/org/jbpm/pvm/internal/env/JbpmConfigurationParser.java 2009-05-06 12:55:13 UTC (rev 4748) +++ jbpm4/trunk/modules/pvm/src/main/java/org/jbpm/pvm/internal/env/JbpmConfigurationParser.java 2009-05-06 14:03:44 UTC (rev 4749) @@ -21,7 +21,6 @@ */ package org.jbpm.pvm.internal.env; -import org.jbpm.api.JbpmException; import org.jbpm.pvm.internal.cfg.JbpmConfiguration; import org.jbpm.pvm.internal.util.XmlUtil; import org.jbpm.pvm.internal.wire.WireDefinition; Modified: jbpm4/trunk/modules/pvm/src/main/java/org/jbpm/pvm/internal/wire/binding/VersionTimestampPolicy.java =================================================================== --- jbpm4/trunk/modules/pvm/src/main/java/org/jbpm/pvm/internal/wire/binding/VersionTimestampPolicy.java 2009-05-06 12:55:13 UTC (rev 4748) +++ jbpm4/trunk/modules/pvm/src/main/java/org/jbpm/pvm/internal/wire/binding/VersionTimestampPolicy.java 2009-05-06 14:03:44 UTC (rev 4749) @@ -22,18 +22,10 @@ package org.jbpm.pvm.internal.wire.binding; import java.io.Serializable; -import java.util.List; -import org.jbpm.api.ProcessDefinition; -import org.jbpm.api.ProcessDefinitionQuery; -import org.jbpm.api.ProcessService; -import org.jbpm.api.client.ClientProcessDefinition; import org.jbpm.api.env.Environment; import org.jbpm.internal.log.Log; import org.jbpm.pvm.internal.repository.DeploymentImpl; -import org.jbpm.pvm.internal.util.XmlUtil; -import org.w3c.dom.Document; -import org.w3c.dom.Element; /** * @author Heiko.Braun <heiko.braun(a)jboss.com&gt; Modified: jbpm4/trunk/modules/pvm/src/main/resources/jbpm.default.cfg.xml =================================================================== --- jbpm4/trunk/modules/pvm/src/main/resources/jbpm.default.cfg.xml 2009-05-06 12:55:13 UTC (rev 4748) +++ jbpm4/trunk/modules/pvm/src/main/resources/jbpm.default.cfg.xml 2009-05-06 14:03:44 UTC (rev 4749) @@ -1,6 +1,6 @@ <?xml version="1.0" encoding="UTF-8"?> -<jbpm-configuration xmlns="http://jbpm.org/xsd/cfg"> +<jbpm-configuration> <process-engine-context> Modified: jbpm4/trunk/modules/pvm/src/main/resources/jbpm.identity.cfg.xml =================================================================== --- jbpm4/trunk/modules/pvm/src/main/resources/jbpm.identity.cfg.xml 2009-05-06 12:55:13 UTC (rev 4748) +++ jbpm4/trunk/modules/pvm/src/main/resources/jbpm.identity.cfg.xml 2009-05-06 14:03:44 UTC (rev 4749) @@ -1,6 +1,6 @@ <?xml version="1.0" encoding="UTF-8"?> -<jbpm-configuration xmlns="http://jbpm.org/xsd/cfg"> +<jbpm-configuration> <transaction-context> <identity-session /> Modified: jbpm4/trunk/modules/pvm/src/main/resources/jbpm.jbossremote.cfg.xml =================================================================== --- jbpm4/trunk/modules/pvm/src/main/resources/jbpm.jbossremote.cfg.xml 2009-05-06 12:55:13 UTC (rev 4748) +++ jbpm4/trunk/modules/pvm/src/main/resources/jbpm.jbossremote.cfg.xml 2009-05-06 14:03:44 UTC (rev 4749) @@ -1,6 +1,6 @@ <?xml version="1.0" encoding="UTF-8"?> -<jbpm-configuration xmlns="http://jbpm.org/xsd/cfg"> +<jbpm-configuration> <process-engine-context> Modified: jbpm4/trunk/modules/pvm/src/main/resources/jbpm.jobexecutor.cfg.xml =================================================================== --- jbpm4/trunk/modules/pvm/src/main/resources/jbpm.jobexecutor.cfg.xml 2009-05-06 12:55:13 UTC (rev 4748) +++ jbpm4/trunk/modules/pvm/src/main/resources/jbpm.jobexecutor.cfg.xml 2009-05-06 14:03:44 UTC (rev 4749) @@ -1,6 +1,6 @@ <?xml version="1.0" encoding="UTF-8"?> -<jbpm-configuration xmlns="http://jbpm.org/xsd/cfg"> +<jbpm-configuration> <process-engine-context> Modified: jbpm4/trunk/modules/pvm/src/main/resources/jbpm.tx.hibernate.cfg.xml =================================================================== --- jbpm4/trunk/modules/pvm/src/main/resources/jbpm.tx.hibernate.cfg.xml 2009-05-06 12:55:13 UTC (rev 4748) +++ jbpm4/trunk/modules/pvm/src/main/resources/jbpm.tx.hibernate.cfg.xml 2009-05-06 14:03:44 UTC (rev 4749) @@ -1,6 +1,6 @@ <?xml version="1.0" encoding="UTF-8"?> -<jbpm-configuration xmlns="http://jbpm.org/xsd/cfg"> +<jbpm-configuration> <process-engine-context> <command-service> Modified: jbpm4/trunk/modules/pvm/src/main/resources/jbpm.tx.jta.cfg.xml =================================================================== --- jbpm4/trunk/modules/pvm/src/main/resources/jbpm.tx.jta.cfg.xml 2009-05-06 12:55:13 UTC (rev 4748) +++ jbpm4/trunk/modules/pvm/src/main/resources/jbpm.tx.jta.cfg.xml 2009-05-06 14:03:44 UTC (rev 4749) @@ -1,6 +1,6 @@ <?xml version="1.0" encoding="UTF-8"?> -<jbpm-configuration xmlns="http://jbpm.org/xsd/cfg"> +<jbpm-configuration> <process-engine-context> <command-service> Modified: jbpm4/trunk/modules/pvm/src/test/resources/jbpm.cfg.xml =================================================================== --- jbpm4/trunk/modules/pvm/src/test/resources/jbpm.cfg.xml 2009-05-06 12:55:13 UTC (rev 4748) +++ jbpm4/trunk/modules/pvm/src/test/resources/jbpm.cfg.xml 2009-05-06 14:03:44 UTC (rev 4749) @@ -1,6 +1,6 @@ <?xml version="1.0" encoding="UTF-8"?> -<jbpm-configuration xmlns="http://jbpm.org/xsd/cfg"> +<jbpm-configuration> <import resource="jbpm.default.cfg.xml" /> <import resource="jbpm.tx.hibernate.cfg.xml" /> Modified: jbpm4/trunk/modules/pvm/src/test/resources/org/jbpm/pvm/api/db/svc/environment.cfg.xml =================================================================== --- jbpm4/trunk/modules/pvm/src/test/resources/org/jbpm/pvm/api/db/svc/environment.cfg.xml 2009-05-06 12:55:13 UTC (rev 4748) +++ jbpm4/trunk/modules/pvm/src/test/resources/org/jbpm/pvm/api/db/svc/environment.cfg.xml 2009-05-06 14:03:44 UTC (rev 4749) @@ -1,6 +1,6 @@ <?xml version="1.0" encoding="UTF-8"?> -<jbpm-configuration xmlns="http://jbpm.org/xsd/cfg"> +<jbpm-configuration> <process-engine-context> Modified: jbpm4/trunk/modules/pvm/src/test/resources/org/jbpm/pvm/api/timer/environment.cfg.xml =================================================================== --- jbpm4/trunk/modules/pvm/src/test/resources/org/jbpm/pvm/api/timer/environment.cfg.xml 2009-05-06 12:55:13 UTC (rev 4748) +++ jbpm4/trunk/modules/pvm/src/test/resources/org/jbpm/pvm/api/timer/environment.cfg.xml 2009-05-06 14:03:44 UTC (rev 4749) @@ -1,6 +1,6 @@ <?xml version="1.0" encoding="UTF-8"?> -<jbpm-configuration xmlns="http://jbpm.org/xsd/cfg"> +<jbpm-configuration> <process-engine-context> Modified: jbpm4/trunk/modules/test-db/src/test/resources/jbpm.cfg.xml =================================================================== --- jbpm4/trunk/modules/test-db/src/test/resources/jbpm.cfg.xml 2009-05-06 12:55:13 UTC (rev 4748) +++ jbpm4/trunk/modules/test-db/src/test/resources/jbpm.cfg.xml 2009-05-06 14:03:44 UTC (rev 4749) @@ -1,6 +1,6 @@ <?xml version="1.0" encoding="UTF-8"?> -<jbpm-configuration xmlns="http://jbpm.org/xsd/cfg"> +<jbpm-configuration> <import resource="jbpm.default.cfg.xml" /> <import resource="jbpm.tx.hibernate.cfg.xml" /> Modified: jbpm4/trunk/modules/test-load/src/test/resources/jbpm.cfg.xml =================================================================== --- jbpm4/trunk/modules/test-load/src/test/resources/jbpm.cfg.xml 2009-05-06 12:55:13 UTC (rev 4748) +++ jbpm4/trunk/modules/test-load/src/test/resources/jbpm.cfg.xml 2009-05-06 14:03:44 UTC (rev 4749) @@ -1,6 +1,6 @@ <?xml version="1.0" encoding="UTF-8"?> -<jbpm-configuration xmlns="http://jbpm.org/xsd/cfg"> +<jbpm-configuration> <import resource="jbpm.default.cfg.xml" /> <import resource="jbpm.tx.hibernate.cfg.xml" /> Modified: jbpm4/trunk/qa/hudson-jbpm4-jboss.sh =================================================================== --- jbpm4/trunk/qa/hudson-jbpm4-jboss.sh 2009-05-06 12:55:13 UTC (rev 4748) +++ jbpm4/trunk/qa/hudson-jbpm4-jboss.sh 2009-05-06 14:03:44 UTC (rev 4749) @@ -2,6 +2,7 @@ # # runs the jboss integration test suite +MAVEN_OPTS="-Xms1024M -Xmx1024M" ANT_PROPERTIES="-Ddatabase=$DATABASE -Djboss.version=$JBOSS_VERSION -Djbpm.parent.dir=$WORKSPACE -Djboss.distro.dir=$SOURCE_REPO/jboss" echo ANT_PROPERTIES=${ANT_PROPERTIES}