In my project,i use the code below to configure the persistence:
try {
PoolingDataSource ds = new PoolingDataSource();
ds.setUniqueName("jdbc/testDS");
ds.setClassName("com.mysql.jdbc.jdbc2.optional.MysqlXADataSource");
ds.setMaxPoolSize(3);
ds.setAllowLocalTransactions(true);
ds.getDriverProperties().put("user", "root");
ds.getDriverProperties().put("password", "root");
ds.getDriverProperties().put("URL", "jdbc:mysql://localhost:3306/jbpm5");
ds.init();
// load up the knowledge base
KnowledgeBase kbase = readKnowledgeBase();
// start a new process instance
EntityManagerFactory emf = Persistence
.createEntityManagerFactory("org.jbpm.persistence.jpa");
Environment env = KnowledgeBaseFactory.newEnvironment();
env.set(EnvironmentName.ENTITY_MANAGER_FACTORY,
emf);
env.set(EnvironmentName.TRANSACTION_MANAGER,
TransactionManagerServices.getTransactionManager());
// create a new knowledge session that uses JPA to store the runtime
// state
StatefulKnowledgeSession ksession=null;
ksession= JPAKnowledgeService.newStatefulKnowledgeSession(
kbase,
null,
env);
JPAWorkingMemoryDbLogger logger = new JPAWorkingMemoryDbLogger(ksession);
ksession.getWorkItemManager().registerWorkItemHandler("Human Task", new WSHumanTaskHandler());
// start a new process instance
Map<String, Object> params = new HashMap<String, Object>();
params.put("employee", "krisv");
ksession.startProcess("com.sample.evaluation",params);
logger.dispose();
} catch (Throwable t) {
t.printStackTrace();
}
However,when i start a new processinstance(I have three task in my process) and try to complete the first task,exception happens just like this:
Registered human task listener
[2011:06:167 10:06:520:debug] Message receieved on client : AddTaskResponse
[2011:06:167 10:06:520:debug] Arguments : [1]
[2011:06:167 10:06:324:debug] Message receieved on client : EventTriggerResponse
[2011:06:167 10:06:324:debug] Arguments : [org.jbpm.task.event.EventPayload@b98a06]
Task completed 1
[2011:06:167 10:06:609:debug] Message receieved on client : GetTaskResponse
[2011:06:167 10:06:609:debug] Arguments : [org.jbpm.task.Task@2a7159ce]
[2011:06:167 10:06:610:exception] Uncaught exception on client
java.lang.IllegalArgumentException: attempt to create merge event with null entity
at org.hibernate.event.MergeEvent.<init>(MergeEvent.java:60)
at org.hibernate.event.MergeEvent.<init>(MergeEvent.java:43)
at org.hibernate.impl.SessionImpl.merge(SessionImpl.java:688)
at org.hibernate.impl.SessionImpl.merge(SessionImpl.java:692)
at org.hibernate.ejb.AbstractEntityManagerImpl.merge(AbstractEntityManagerImpl.java:235)
at org.drools.persistence.jpa.JpaPersistenceContext.merge(JpaPersistenceContext.java:49)
at org.drools.persistence.jpa.processinstance.JPAWorkItemManager.abortWorkItem(JPAWorkItemManager.java:136)
at org.jbpm.process.workitem.wsht.WSHumanTaskHandler$GetCompletedTaskResponseHandler.execute(WSHumanTaskHandler.java:249)
at org.jbpm.task.service.TaskClientHandler.messageReceived(TaskClientHandler.java:81)
at org.jbpm.task.service.mina.MinaTaskClientHandler.messageReceived(MinaTaskClientHandler.java:47)
at org.apache.mina.core.filterchain.DefaultIoFilterChain$TailFilter.messageReceived(DefaultIoFilterChain.java:713)
at org.apache.mina.core.filterchain.DefaultIoFilterChain.callNextMessageReceived(DefaultIoFilterChain.java:434)
at org.apache.mina.core.filterchain.DefaultIoFilterChain.access$1200(DefaultIoFilterChain.java:46)
at org.apache.mina.core.filterchain.DefaultIoFilterChain$EntryImpl$1.messageReceived(DefaultIoFilterChain.java:793)
at org.apache.mina.filter.codec.ProtocolCodecFilter$ProtocolDecoderOutputImpl.flush(ProtocolCodecFilter.java:375)
at org.apache.mina.filter.codec.ProtocolCodecFilter.messageReceived(ProtocolCodecFilter.java:229)
at org.apache.mina.core.filterchain.DefaultIoFilterChain.callNextMessageReceived(DefaultIoFilterChain.java:434)
at org.apache.mina.core.filterchain.DefaultIoFilterChain.access$1200(DefaultIoFilterChain.java:46)
at org.apache.mina.core.filterchain.DefaultIoFilterChain$EntryImpl$1.messageReceived(DefaultIoFilterChain.java:793)
at org.apache.mina.core.filterchain.IoFilterAdapter.messageReceived(IoFilterAdapter.java:119)
at org.apache.mina.core.filterchain.DefaultIoFilterChain.callNextMessageReceived(DefaultIoFilterChain.java:434)
at org.apache.mina.core.filterchain.DefaultIoFilterChain.fireMessageReceived(DefaultIoFilterChain.java:426)
at org.apache.mina.core.polling.AbstractPollingIoProcessor.read(AbstractPollingIoProcessor.java:638)
at org.apache.mina.core.polling.AbstractPollingIoProcessor.process(AbstractPollingIoProcessor.java:598)
at org.apache.mina.core.polling.AbstractPollingIoProcessor.process(AbstractPollingIoProcessor.java:587)
at org.apache.mina.core.polling.AbstractPollingIoProcessor.access$400(AbstractPollingIoProcessor.java:61)
at org.apache.mina.core.polling.AbstractPollingIoProcessor$Processor.run(AbstractPollingIoProcessor.java:969)
at org.apache.mina.util.NamePreservingRunnable.run(NamePreservingRunnable.java:64)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:619)
After the exception,the task stored in the database has a "completed" status,Can somebody help me to solve the problem?