[seam-commits] Seam SVN: r7263 - trunk/doc/reference/en.

Author: jbalunas(a)redhat.com Date: 2008-01-28 16:26:54 -0500 (Mon, 28 Jan 2008) New Revision: 7263 Removed: trunk/doc/reference/en/master.xml Log: added websphere chapter Deleted: trunk/doc/reference/en/master.xml =================================================================== --- trunk/doc/reference/en/master.xml 2008-01-28 21:02:44 UTC (rev 7262) +++ trunk/doc/reference/en/master.xml 2008-01-28 21:26:54 UTC (rev 7263) @@ -1,375 +0,0 @@ -<?xml version='1.0' encoding="iso-8859-1"?> -<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.3CR3//EN" - "../support/docbook-dtd/docbookx.dtd" -[ -<!ENTITY tutorial SYSTEM "modules/tutorial.xml"> -<!ENTITY gettingstarted SYSTEM "modules/gettingstarted.xml"> -<!ENTITY concepts SYSTEM "modules/concepts.xml"> -<!ENTITY xml SYSTEM "modules/xml.xml"> -<!ENTITY events SYSTEM "modules/events.xml"> -<!ENTITY conversations SYSTEM "modules/conversations.xml"> -<!ENTITY jbpm SYSTEM "modules/jbpm.xml"> -<!ENTITY persistence SYSTEM "modules/persistence.xml"> -<!ENTITY validation SYSTEM "modules/validation.xml"> -<!ENTITY groovy SYSTEM "modules/groovy.xml"> -<!ENTITY framework SYSTEM "modules/framework.xml"> -<!ENTITY drools SYSTEM "modules/drools.xml"> -<!ENTITY security SYSTEM "modules/security.xml"> -<!ENTITY i18n SYSTEM "modules/i18n.xml"> -<!ENTITY text SYSTEM "modules/text.xml"> -<!ENTITY itext SYSTEM "modules/itext.xml"> -<!ENTITY mail SYSTEM "modules/mail.xml"> -<!ENTITY jms SYSTEM "modules/jms.xml"> -<!ENTITY cache SYSTEM "modules/cache.xml"> -<!ENTITY webservices SYSTEM "modules/webservices.xml"> -<!ENTITY remoting SYSTEM "modules/remoting.xml"> -<!ENTITY gwt SYSTEM "modules/gwt.xml"> -<!ENTITY spring SYSTEM "modules/spring.xml"> -<!ENTITY hsearch SYSTEM "modules/hsearch.xml"> -<!ENTITY configuration SYSTEM "modules/configuration.xml"> -<!ENTITY annotations SYSTEM "modules/annotations.xml"> -<!ENTITY components SYSTEM "modules/components.xml"> -<!ENTITY controls SYSTEM "modules/controls.xml"> -<!ENTITY elenhancements SYSTEM "modules/elenhancements.xml"> -<!ENTITY testing SYSTEM "modules/testing.xml"> -<!ENTITY tools SYSTEM "modules/tools.xml"> -<!ENTITY oc4j SYSTEM "modules/oc4j.xml"> -<!ENTITY weblogic SYSTEM "modules/weblogic.xml"> -<!ENTITY dependencies SYSTEM "modules/dependencies.xml"> -]> - -<book lang="en"> - <bookinfo> - <title>Seam - Contextual Components</title> - <subtitle>A Framework for Enterprise Java</subtitle> - <releaseinfo>@version@</releaseinfo> - </bookinfo> - - <toc/> - - <preface> - <title>Introduction to JBoss Seam</title> - - <para> - Seam is an application framework for Enterprise Java. It is inspired by the following principles: - </para> - - <variablelist> - - <varlistentry> - <term><emphasis>One kind of "stuff"</emphasis></term> - <listitem> - <para> - Seam defines a uniform component model for all business logic in your application. - A Seam component may be stateful, with the state associated with any one of several - well-defined contexts, including the long-running, persistent, <emphasis>business process - context</emphasis> and the <emphasis>conversation context</emphasis>, which is - preserved across multiple web requests in a user interaction. - </para> - <para> - There is no distinction between presentation tier components and business logic - components in Seam. You can layer your application according to whatever architecture - you devise, rather than being forced to shoehorn your application logic into an - unnatural layering scheme forced upon you by whatever combination of stovepipe - frameworks you're using today. - </para> - <para> - Unlike plain Java EE or J2EE components, Seam components may <emphasis>simultaneously</emphasis> - access state associated with the web request and state held in transactional resources (without - the need to propagate web request state manually via method parameters). You might object - that the application layering imposed upon you by the old J2EE platform was a Good Thing. - Well, nothing stops you creating an equivalent layered architecture using Seam&#8212;the difference - is that <emphasis>you</emphasis> get to architect your own application and decide what the - layers are and how they work together. - </para> - </listitem> - </varlistentry> - - <varlistentry> - <term><emphasis>Integrate JSF with EJB 3.0</emphasis></term> - <listitem> - <para> - JSF and EJB 3.0 are two of the best new features of Java EE 5. EJB3 is a brand new - component model for server side business and persistence logic. Meanwhile, JSF is a - great component model for the presentation tier. Unfortunately, neither component - model is able to solve all problems in computing by itself. Indeed, JSF and EJB3 - work best used together. But the Java EE 5 specification provides no standard way - to integrate the two component models. Fortunately, the creators of both models - foresaw this situation and provided standard extension points to allow extension - and integration with other frameworks. - </para> - <para> - Seam unifies the component models of JSF and EJB3, eliminating glue code, and letting - the developer think about the business problem. - </para> - <para> - It is possible to write Seam applications where "everything" is an EJB. This may come - as a surprise if you're used to thinking of EJBs as coarse-grained, so-called - "heavyweight" objects. However, version 3.0 has completely changed the nature of EJB - from the point of view of the developer. An EJB is a fine-grained object&#8212;nothing - more complex than an annotated JavaBean. Seam even encourages you to use session beans - as JSF action listeners! - </para> - <para> - On the other hand, if you prefer not to adopt EJB 3.0 at this time, you don't have to. - Virtually any Java class may be a Seam component, and Seam provides all the functionality - that you expect from a "lightweight" container, and more, for any component, EJB or - otherwise. - </para> - </listitem> - </varlistentry> - - <varlistentry> - <term><emphasis>Integrated AJAX</emphasis></term> - <listitem> - <para> - Seam supports the best open source JSF-based AJAX solutions: JBoss RichFaces and - ICEfaces. These solutions let you add AJAX capability to your user interface without - the need to write any JavaScript code. - </para> - <para> - Alternatively, Seam provides a built-in JavaScript remoting layer that lets you call - components asynchronously from client-side JavaScript without the need for an intermediate - action layer. You can even subscribe to server-side JMS topics and receive messages via AJAX - push. - </para> - <para> - Neither of these approaches would work well, were it not for Seam's built-in concurrency - and state management, which ensures that many concurrent fine-grained, asynchronous AJAX - requests are handled safely and efficiently on the server side. - </para> - </listitem> - </varlistentry> - - <varlistentry> - <term><emphasis>Business process as a first class construct</emphasis></term> - <listitem> - <para> - Optionally, Seam provides transparent business process management via jBPM. You won't - believe how easy it is to implement complex workflows, collaboration and and task management - using jBPM and Seam. - </para> - <para> - Seam even allows you to define presentation tier pageflow using the same language (jPDL) - that jBPM uses for business process definition. - </para> - <para> - JSF provides an incredibly rich event model for the presentation tier. Seam enhances this - model by exposing jBPM's business process related events via exactly the same event handling - mechanism, providing a uniform event model for Seam's uniform component model. - </para> - </listitem> - </varlistentry> - - <varlistentry> - <term><emphasis>Declarative state management</emphasis></term> - <listitem> - <para> - We're all used to the concept of declarative transaction management and declarative - security from the early days of EJB. EJB 3.0 even introduces declarative persistence context - management. These are three examples of a broader problem of managing state that is - associated with a particular <emphasis>context</emphasis>, while ensuring that all needed - cleanup occurs when the context ends. Seam takes the concept of declarative state - management much further and applies it to <emphasis>application state</emphasis>. - Traditionally, J2EE applications implement state management manually, by getting - and setting servlet session and request attributes. This approach to state management is the - source of many bugs and memory leaks when applications fail to clean up session attributes, - or when session data associated with different workflows collides in a multi-window - application. Seam has the potential to almost entirely eliminate this class of bugs. - </para> - <para> - Declarative application state management is made possible by the richness of the - <emphasis>context model</emphasis> defined by Seam. Seam extends the context model defined - by the servlet spec&#8212;request, session, application&#8212;with two new - contexts&#8212;conversation and business process&#8212;that are more meaningful from the - point of view of the business logic. - </para> - <para> - You'll be amazed at how many things become easier once you start using conversations. - Have you ever suffered pain dealing with lazy association fetching in an ORM solution - like Hibernate or JPA? Seam's conversation-scoped persistence contexts mean you'll - rarely have to see a <literal>LazyInitializationException</literal>. Have you ever - had problems with the refresh button? The back button? With duplicate form submission? - With propagating messages across a post-then-redirect? Seam's conversation management - solves these problems without you even needing to really think about them. They're all - symptoms of the broken state management architecture that has been prevalent since the - earliest days of the web. - </para> - </listitem> - </varlistentry> - - <varlistentry> - <term><emphasis>Bijection</emphasis></term> - <listitem> - <para> - The notion of <emphasis>Inversion of Control</emphasis> or <emphasis>dependency injection</emphasis> - exists in both JSF and EJB3, as well as in numerous so-called "lightweight containers". Most of - these containers emphasize injection of components that implement <emphasis>stateless services</emphasis>. - Even when injection of stateful components is supported (such as in JSF), it is virtually useless - for handling application state because the scope of the stateful component cannot be defined with - sufficient flexibility, and because components belonging to wider scopes may not be injected into - components belonging to narrower scopes. - </para> - <para> - <emphasis>Bijection</emphasis> differs from IoC in that it is <emphasis>dynamic</emphasis>, - <emphasis>contextual</emphasis>, and <emphasis>bidirectional</emphasis>. - You can think of it as a mechanism for aliasing contextual variables (names in the various contexts - bound to the current thread) to attributes of the component. Bijection allows auto-assembly of stateful - components by the container. It even allows a component to safely and easily manipulate the - value of a context variable, just by assigning it to an attribute of the component. - </para> - </listitem> - </varlistentry> - - <varlistentry> - <term><emphasis>Workspace management and multi-window browsing</emphasis></term> - <listitem> - <para> - Seam applications let the user freely switch between multiple browser tabs, each associated with a - different, safely isolated, conversation. Applications may even take advantage of <emphasis>workspace - management</emphasis>, allowing the user to switch between conversations (workspaces) in a single - browser tab. Seam provides not only correct multi-window operation, but also multi-window-like - operation in a single window! - </para> - </listitem> - </varlistentry> - - <varlistentry> - <term><emphasis>Prefer annotations to XML</emphasis></term> - <listitem> - <para> - Traditionally, the Java community has been in a state of deep confusion about precisely - what kinds of meta-information counts as configuration. J2EE and popular "lightweight" - containers have provided XML-based deployment descriptors both for things which are - truly configurable between different deployments of the system, and for any other kinds - or declaration which can not easily be expressed in Java. Java 5 annotations changed - all this. - </para> - <para> - EJB 3.0 embraces annotations and "configuration by exception" as the easiest way to provide - information to the container in a declarative form. Unfortunately, JSF is still heavily - dependent on verbose XML configuration files. Seam extends the annotations provided by - EJB 3.0 with a set of annotations for declarative state management and declarative - context demarcation. This lets you eliminate the noisy JSF managed bean declarations - and reduce the required XML to just that information which truly belongs in XML - (the JSF navigation rules). - </para> - </listitem> - </varlistentry> - - <varlistentry> - <term><emphasis>Integration testing is easy</emphasis></term> - <listitem> - <para> - Seam components, being plain Java classes, are by nature unit testable. But for complex applications, - unit testing alone is insufficient. Integration testing has traditionally been a messy and - difficult task for Java web applications. Therefore, Seam provides for testability of Seam - applications as a core feature of the framework. You can easily write JUnit or TestNG tests - that reproduce a whole interaction with a user, exercising all components of the system - apart from the view (the JSP or Facelets page). You can run these tests directly inside your - IDE, where Seam will automatically deploy EJB components using JBoss Embedded. - </para> - </listitem> - </varlistentry> - - <varlistentry> - <term><emphasis>The specs ain't perfect</emphasis></term> - <listitem> - <para> - We think the latest incarnation of Java EE is great. But we know it's never going to be - perfect. Where there are holes in the specifications (for example, limitations in the - JSF lifecycle for GET requests), Seam fixes them. And the authors of Seam are working - with the JCP expert groups to make sure those fixes make their way back into the next - revision of the standards. - </para> - </listitem> - </varlistentry> - - <varlistentry> - <term><emphasis>There's more to a web application than serving HTML pages</emphasis></term> - <listitem> - <para> - Today's web frameworks think too small. They let you get user input off a form and - into your Java objects. And then they leave you hanging. A truly complete web application - framework should address problems like persistence, concurrency, asynchronicity, state - management, security, email, messaging, PDF and chart generation, workflow, wikitext - rendering, webservices, caching and more. Once you scratch the surface of Seam, you'll - be amazed at how many problems become simpler... - </para> - <para> - Seam integrates JPA and Hibernate3 for persistence, the EJB Timer Service and Quartz - for lightweight asychronicity, jBPM for workflow, JBoss Rules for business rules, Meldware - Mail for email, Hibernate Search and Lucene for full text search, JMS for messaging and JBoss - Cache for page fragment caching. Seam layers an innovative rule-based security framework over - JAAS and JBoss Rules. There's even JSF tag libraries for rendering PDF, outgoing email, charts - and wikitext. Seam components may be called synchronously as a Web Service, asynchronously - from client-side JavaScript or Google Web Toolkit or, of course, directly from JSF. - </para> - </listitem> - </varlistentry> - - <varlistentry> - <term><emphasis>Get started now!</emphasis></term> - <listitem> - <para> - Seam works in any Java EE application server, and even works in Tomcat. If your environment - supports EJB 3.0, great! If it doesn't, no problem, you can use Seam's built-in transaction - management with JPA or Hibernate3 for persistence. Or, you can deploy JBoss Embedded in - Tomcat, and get full support for EJB 3.0. - </para> - </listitem> - </varlistentry> - </variablelist> - - <mediaobject> - <imageobject role="fo"> - <imagedata fileref="images/architecture.png" align="center"/> - </imageobject> - <imageobject role="html"> - <imagedata fileref="../shared/images/architecture.png" align="center"/> - </imageobject> - </mediaobject> - - <para> - It turns out that the combination of Seam, JSF and EJB3 is <emphasis>the</emphasis> simplest way - to write a complex web application in Java. You won't believe how little code is required! - </para> - - </preface> - - &tutorial; - &gettingstarted; - &concepts; - &xml; - &events; - &conversations; - &jbpm; - &persistence; - &validation; - &groovy; - &framework; - &drools; - &security; - &i18n; - &text; - &itext; - &mail; - &jms; - &cache; - &webservices; - &remoting; - &gwt; - &spring; - &hsearch; - &configuration; - &oc4j; - &weblogic; - &annotations; - &components; - &controls; - &elenhancements; - &testing; - &tools; - &dependencies; -</book> -