JBossDeveloper

I am getting following exception when I am using ProcessInstance.signal()..
can anyone get me out from this problem......


org.jbpm.graph.def.DelegationException
at org.jbpm.graph.def.GraphElement.raiseException(GraphElement.java:367)
at org.jbpm.graph.def.GraphElement.raiseException(GraphElement.java:358)
at org.jbpm.graph.def.Node.execute(Node.java:343)
at org.jbpm.graph.def.Node.enter(Node.java:318)
at org.jbpm.graph.def.Transition.take(Transition.java:151)
at org.jbpm.graph.def.Node.leave(Node.java:393)
at org.jbpm.graph.node.StartState.leave(StartState.java:70)
at org.jbpm.graph.exe.Token.signal(Token.java:194)
at org.jbpm.graph.exe.Token.signal(Token.java:139)
at org.jbpm.graph.exe.ProcessInstance.signal(ProcessInstance.java:251)
at my.com.Test.EmailTest.testSendMail(EmailTest.java:51)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at junit.framework.TestCase.runTest(TestCase.java:154)
at junit.framework.TestCase.runBare(TestCase.java:127)
at junit.framework.TestResult$1.protect(TestResult.java:106)
at junit.framework.TestResult.runProtected(TestResult.java:124)
at junit.framework.TestResult.run(TestResult.java:109)
at junit.framework.TestCase.run(TestCase.java:118)
at junit.framework.TestSuite.runTest(TestSuite.java:208)
at junit.framework.TestSuite.run(TestSuite.java:203)
at org.eclipse.jdt.internal.junit.runner.junit3.JUnit3TestReference.run(JUnit3TestReference.java:130)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:460)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:673)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:386)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:196)
Caused by: java.lang.NullPointerException
at org.jbpm.graph.def.Action.execute(Action.java:122)
at org.jbpm.graph.def.Node.execute(Node.java:338)
... 26 more

totally unrelated... use a new topic for this. oh and the exception you get in most cases means jbpm cannot find the delegation class.