NullPointerException after signal token in Process State wit

[kirq4e]

Hi guys,

Recently me and my colleague started learning jBPM for our new project. I have started creating some processes to learn its capabilities.
We have developed a simple Parent-Children scenario.

The parent process is:

<?xml version="1.0" encoding="UTF-8"?>
<process-definition xmlns="" name="ParentProcess">
 <start-state name="start">
 <transition to="SetInputVariable" name="toSetInputVariable"></transition>
 </start-state>

 <process-state name="InvokeChildProcess">
 <sub-process name="ChildProcess" binding="late"></sub-process>
 <variable access="read" name="parentKey"></variable>
 <variable access="read,write" name="lastVisitedProcess"></variable>
 <transition to="PrintVariables" name="toPrintVariables"></transition>
 </process-state>

 <node name="SetInputVariable">
 <action class="com.sirma.ecs2.test.subprocess.actions.SetInputVariables"></action>
 <transition to="InvokeChildProcess" name="toInvokeChildProcess"></transition>
 </node>

 <node name="PrintVariables">
 <action class="com.sirma.ecs2.test.subprocess.actions.PrintVariables"></action>
 <transition to="end" name="toEnd"></transition>
 </node>
 <end-state name="end"></end-state>
</process-definition>

The child process is:

<?xml version="1.0" encoding="UTF-8"?>
<process-definition xmlns="" name="ChildProcess">
 <start-state name="start">
 <transition to="Reset Variables" name="toResetVariables"></transition>
 </start-state>

 <node name="Reset Variables">
 <action name="Reset Variables" class="com.sirma.ecs2.test.subprocess.actions.ResetVariables"></action>
 <transition to="WaitSignal" name="toWaitSignal"></transition>
 </node>

 <state name="WaitSignal">
 <transition to="end" name="toEnd">
 <action class="com.sirma.ecs2.test.subprocess.actions.ExitWait"></action>
 </transition>
 </state>
 <end-state name="end"></end-state>
</process-definition>

I start a Parent process and signal it the Token stops at the child`s State node: WaitSignal.
The Root token of the parent node is in InvokeChildProcess. The ActionHandlers are very simple just print a message and work with some variables.

If i try to signal the Parent process`s root node i got a NullPointerException:

Caused by: java.lang.NullPointerException
 at org.jbpm.graph.node.ProcessState.leave(ProcessState.java:186)
 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
 at java.lang.reflect.Method.invoke(Method.java:585)
 at org.hibernate.proxy.pojo.javassist.JavassistLazyInitializer.invoke(JavassistLazyInitializer.java:173)
 at org.jbpm.graph.def.Node_$$_javassist_49.leave(Node_$$_javassist_49.java)
 at org.jbpm.graph.exe.Token.signal(Token.java:192)
 at org.jbpm.graph.exe.Token.signal(Token.java:140)
 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
 at java.lang.reflect.Method.invoke(Method.java:585)
 at org.hibernate.proxy.pojo.javassist.JavassistLazyInitializer.invoke(JavassistLazyInitializer.java:173)
 at org.jbpm.graph.exe.Token_$$_javassist_64.signal(Token_$$_javassist_64.java)
 at com.kpenev.test.TestBean.signalToken(Unknown Source)

Probably the right token that i have to signal is the token of the subprocess, but i don`t think that such an exception should occur.

The code that i execute is:

JbpmContext jbpmContext = JbpmConfiguration.getInstance()
 .createJbpmContext();
 try {
 ProcessInstance instance = jbpmContext.getGraphSession()
 .loadProcessInstance(instanceID);
 instance.getRootToken().signal();
 } finally {
 jbpmContext.close();
 }

The code that really works is:

JbpmContext jbpmContext = JbpmConfiguration.getInstance()
 .createJbpmContext();
 try {
 ProcessInstance instance = jbpmContext.getGraphSession()
 .loadProcessInstance(instanceID);
 instance.getRootToken().getSubProcessInstance().getRootToken()
 .signal();
 } finally {
 jbpmContext.close();
 }

I`m using jbpm-3.3.0.GA version and jboss-4.2.3.GA.

I debuged it and the subProcessInstance variable at ExecutionContext isn`t set.

Hope there is a solution for this, because in the near future i have to develop a very complex processes including subprocesses.

[kukeltje]

Probably the right token that i have to signal is the token of the subprocess, but i don`t think that such an exception should occur.

You are probably right that a nullpointer exception is what should happen

Hope there is a solution for this, because in the near future i have to develop a very complex processes including subprocesses.

Solution to 'this'? The nullpointer? I think the only change in jBPM would be that you get another exception, something like 'cannot signal this token since it has active subprocesses'. So the real solution is to signal the correct token as you already have show to work. Or do I miss something?

[kirq4e]

I don`t know what is the right solution. :)

I just find it and decided that it will be good to notify you for this problem. Probably the right will be to throw an exception. It`s not right to occur NullPointerException. I leave it to you guys, but I hope that there will be info for the fix.

[kukeltje]

Ok ,,thanks.. and I made a typo... It should have said 'is *not* what should happen, so we agree ;-)