Class could not be found by the process classloader

[fidalma]

Hi all,
I'm doing several tests with JBpm and in this moment I'm trying
to execute a script command by an ActionHandler class implementation,
but I have a problem and in order to explain it correctly I attach my code.

-------------------------------------- PROCESS DEFINITION --------------------------------------

<?xml version="1.0" encoding="UTF-8"?>
<process-definition xmlns="urn:jbpm.org:jpdl-3.1" name="Initiator">
 <swimlane name="initiator" />
 <start-state name="start new process">
 <task swimlane="process initiator" />
 <transition name="tr1" to="decision">
 <action name="action"
 class="com.sample.action.SampleActionHendler">
 <message>Executing SampleActionHendler!</message>
 </action>
 </transition>
 </start-state>
 <decision name="decision">
 <handler
 class="com.sample.decision.SampleDecisionHendler">
 </handler>
 <transition name="tr2" to="action"></transition>
 <transition name="tr3" to="end1"></transition>
 </decision>
 <state name="action">
 <transition name="tr4" to="end1"></transition>
 </state>
 <end-state name="end1"></end-state>
</process-definition>


---------------------------------------- MY ACTION HANDLER --------------------------------------


package com.sample.action;

import org.jbpm.graph.def.ActionHandler;
import org.jbpm.graph.exe.ExecutionContext;

public class SampleActionHandler implements ActionHandler
{
 private static final long serialVersionUID = 1L;
 public void execute(ExecutionContext context) throws Exception
 {
 Runtime rt = null;
 Process process = null;

 context.getContextInstance().createVariable("greeting", "Greeting from SampleActionHandler");
 try
 {
 rt = Runtime.getRuntime();
 process = rt.exec("C:\\Applications~1\\ECLIPSE~1\\Start.bat");
 context.getContextInstance().createVariable("status", new Integer(process.waitFor()));
 }
 catch (Exception e)
 {
 System.out.println(e);
 context.getContextInstance().createVariable("budget", new Integer(1));
 }
 }
}


------------------------------------- MY DECISION HANDLER --------------------------------------


package com.sample.decision;

import org.jbpm.graph.exe.ExecutionContext;
import org.jbpm.graph.node.DecisionHandler;

public class SampleDecisionHandler implements DecisionHandler
{
 private static final long serialVersionUID = 1L;
 public String decide(ExecutionContext context) throws Exception
 {
 int budget = ((Number)context.getContextInstance().getVariable("status")).intValue();
 if (budget == 0) return "tr2";
 else if (budget == 1) return "tr3";
 else return "tr3";
 }
}


---------------------------------------- MY TEST CASE ----------------------------------------


package com.sample.test;

import com.sample.action.SampleActionHandler;
import org.jbpm.graph.def.ProcessDefinition;
import org.jbpm.graph.exe.ProcessInstance;
import junit.framework.TestCase;

public class InitiatorTest extends TestCase
{
 public void testProcess() throws Exception
 {
 ProcessDefinition definition = ProcessDefinition.parseXmlResource("Initiator.par/processdefinition.xml");
 assertNotNull("Definition should not be null", definition);

 ProcessInstance instance = new ProcessInstance(definition);
 assertEquals("Instance is in start state", instance.getRootToken().getNode().getName(),"start new process");
 instance.signal();

 if(((Number)instance.getContextInstance().getVariable("status")).intValue() == 0)
 {
 assertEquals(definition.getNode("action"), instance.getRootToken().getNode());
 instance.signal();
 }

 assertEquals("Instance is in end state", instance.getRootToken().getNode().getName(),"end1");
 }
}


---------------------------------- MY EXCEPTION EXECUTING MY TEST CASE ----------------------------------

If I run as JUnit Test my Test Case clss I have theese exceptions:

15:39:09,863 [main] INFO JbpmConfiguration : using jbpm configuration resource 'jbpm.cfg.xml'
15:39:10,269 [main] DEBUG JbpmConfiguration : creating jbpm configuration from input stream
15:39:10,644 [main] DEBUG JpdlParser$JpdlEntityResolver : resolving schema reference publicId(null) systemId(http://jbpm.org/jpdl-3.1.xsd)
15:39:10,644 [main] DEBUG JpdlParser$JpdlEntityResolver : providing input source to local 'jpdl-3.1.xsd' resource
15:39:10,801 [main] WARN JpdlXmlReader : process xml warning: swimlane 'initiator' does not have an assignment
15:39:10,847 [main] DEBUG NodeTypes : node 'page' will not be available. class 'org.jboss.seam.jbpm.Page' couldn't be loaded
15:39:10,910 [main] WARN JpdlXmlReader : process xml warning: task references unknown swimlane 'process initiator':<task xmlns="urn:jbpm.org:jpdl-3.1" swimlane="process initiator" blocking="false" signalling="true" priority="normal"/>
15:39:10,941 [main] WARN JpdlXmlReader : process xml warning: swimlane 'initiator' does not have an assignment
15:39:10,972 [main] DEBUG GraphElement : event 'process-start' on 'ProcessDefinition(Initiator)' for 'Token(/)'
15:39:10,972 [main] DEBUG GraphElement : event 'before-signal' on 'StartState(start new process)' for 'Token(/)'
15:39:10,972 [main] DEBUG GraphElement : event 'node-leave' on 'StartState(start new process)' for 'Token(/)'
15:39:10,972 [main] DEBUG GraphElement : event 'transition' on 'Transition(tr1)' for 'Token(/)'
15:39:10,972 [main] DEBUG GraphElement : executing action 'action[action]'
15:39:10,988 [main] ERROR Delegation : couldn't load delegation class 'com.sample.action.SampleActionHendler'
java.lang.ClassNotFoundException: class 'com.sample.action.SampleActionHendler' could not be found by the process classloader
 at org.jbpm.instantiation.ProcessClassLoader.findClass(ProcessClassLoader.java:60)
 at java.lang.ClassLoader.loadClass(ClassLoader.java:289)
 at java.lang.ClassLoader.loadClass(ClassLoader.java:235)
 at org.jbpm.instantiation.Delegation.instantiate(Delegation.java:140)
 at org.jbpm.instantiation.Delegation.getInstance(Delegation.java:125)
 at org.jbpm.graph.def.Action.execute(Action.java:122)
 at org.jbpm.graph.def.GraphElement.executeAction(GraphElement.java:235)
 at org.jbpm.graph.def.GraphElement.executeActions(GraphElement.java:212)
 at org.jbpm.graph.def.GraphElement.fireAndPropagateEvent(GraphElement.java:182)
 at org.jbpm.graph.def.GraphElement.fireEvent(GraphElement.java:166)
 at org.jbpm.graph.def.Transition.take(Transition.java:106)
 at org.jbpm.graph.def.Node.leave(Node.java:382)
 at org.jbpm.graph.node.StartState.leave(StartState.java:70)
 at org.jbpm.graph.exe.Token.signal(Token.java:174)
 at org.jbpm.graph.exe.Token.signal(Token.java:123)
 at org.jbpm.graph.exe.ProcessInstance.signal(ProcessInstance.java:217)
 at com.sample.test.InitiatorTest.testProcess(InitiatorTest.java:19)
 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:324)
 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 org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:478)
 at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:344)
 at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:196)
15:39:10,988 [main] ERROR Delegation : couldn't instantiate delegation class 'com.sample.action.SampleActionHendler'
java.lang.NullPointerException
 at org.jbpm.instantiation.FieldInstantiator.newInstance(FieldInstantiator.java:89)
 at org.jbpm.instantiation.FieldInstantiator.instantiate(FieldInstantiator.java:48)
 at org.jbpm.instantiation.Delegation.instantiate(Delegation.java:163)
 at org.jbpm.instantiation.Delegation.getInstance(Delegation.java:125)
 at org.jbpm.graph.def.Action.execute(Action.java:122)
 at org.jbpm.graph.def.GraphElement.executeAction(GraphElement.java:235)
 at org.jbpm.graph.def.GraphElement.executeActions(GraphElement.java:212)
 at org.jbpm.graph.def.GraphElement.fireAndPropagateEvent(GraphElement.java:182)
 at org.jbpm.graph.def.GraphElement.fireEvent(GraphElement.java:166)
 at org.jbpm.graph.def.Transition.take(Transition.java:106)
 at org.jbpm.graph.def.Node.leave(Node.java:382)
 at org.jbpm.graph.node.StartState.leave(StartState.java:70)
 at org.jbpm.graph.exe.Token.signal(Token.java:174)
 at org.jbpm.graph.exe.Token.signal(Token.java:123)
 at org.jbpm.graph.exe.ProcessInstance.signal(ProcessInstance.java:217)
 at com.sample.test.InitiatorTest.testProcess(InitiatorTest.java:19)
 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:324)
 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 org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:478)
 at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:344)
 at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:196)
15:39:11,004 [main] ERROR GraphElement : action threw exception: null
java.lang.NullPointerException
 at org.jbpm.graph.def.Action.execute(Action.java:123)
 at org.jbpm.graph.def.GraphElement.executeAction(GraphElement.java:235)
 at org.jbpm.graph.def.GraphElement.executeActions(GraphElement.java:212)
 at org.jbpm.graph.def.GraphElement.fireAndPropagateEvent(GraphElement.java:182)
 at org.jbpm.graph.def.GraphElement.fireEvent(GraphElement.java:166)
 at org.jbpm.graph.def.Transition.take(Transition.java:106)
 at org.jbpm.graph.def.Node.leave(Node.java:382)
 at org.jbpm.graph.node.StartState.leave(StartState.java:70)
 at org.jbpm.graph.exe.Token.signal(Token.java:174)
 at org.jbpm.graph.exe.Token.signal(Token.java:123)
 at org.jbpm.graph.exe.ProcessInstance.signal(ProcessInstance.java:217)
 at com.sample.test.InitiatorTest.testProcess(InitiatorTest.java:19)
 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:324)
 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 org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:478)
 at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:344)
 at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:196)


-------------------------------------------------------------------------------------------------

I don't understand why I'm having this error...
Could someone help me please?!
Thank you very much in advance.

Fidalma
Italy

[aguizar]

Your action handler class does not seem to be on the classpath. Are you using the GPD? If so, did you modify the build path of the Eclipse project?

[fidalma]

Hi Alex,
yes I'm using the Eclipse GPD, but when I build my project I don't have errors in compilation so I thought my classpath was ok. How do I have to modify the build path of Eclipse Project ?
Thank you very much !!

Bye,
Fidalma

[koen.aers]

Fidalma,

It is a typo in your processdefinition file. You typed 'SampleActionHendler' instead of 'SampleActionHandler'.

Regards,
Koen

[fidalma]

Noooo I can't believe it !!
I'm really blind and so sorry ... :-((
thanky very much !!

Bye,
Fidalma

[fidalma]

Hi all,
I am always in trouble... sigh...
I have solved the previous stupid problem, but now I have another one.
This is the situation:

-------------------------------------- PROCESS DEFINITION --------------------------------------

<?xml version="1.0" encoding="UTF-8"?>
<process-definition xmlns="urn:jbpm.org:jpdl-3.1" name="Initiator">
 <swimlane name="initiator" />
 <start-state name="start new process">
 <task swimlane="process initiator" />
 <transition name="tr1" to="decision">
 <action name="action" class="com.sample.action.SampleActionHandler">
 </action>
 </transition>
 </start-state>
 <decision name="decision">
 <handler class="com.sample.decision.SampleDecisionHandler"></handler>
 <transition name="tr2" to="action"></transition>
 <transition name="tr3" to="end1"></transition>
 </decision>
 <state name="action">
 <transition name="tr4" to="end1"></transition>
 </state>
 <end-state name="end1"></end-state>
</process-definition>
---------------------------------------- MY ACTION HANDLER --------------------------------------


package com.sample.action;

import org.jbpm.graph.def.ActionHandler;
import org.jbpm.graph.exe.ExecutionContext;

public class SampleActionHandler implements ActionHandler
{
 private static final long serialVersionUID = 1L;
 public void execute(ExecutionContext context) throws Exception
 {
 Runtime rt = null;
 Process process = null;

 context.getContextInstance().createVariable("greeting", "Greeting from SampleActionHandler");
 try
 {
 rt = Runtime.getRuntime();
 process = rt.exec("C:\\Applications~1\\ECLIPSE~1\\Start.bat");
 context.getContextInstance().createVariable("status", new Integer(process.waitFor()));
 }
 catch (Exception e)
 {
 System.out.println(e);
 context.getContextInstance().createVariable("budget", new Integer(1));
 }
 }
}


------------------------------------- MY DECISION HANDLER --------------------------------------


package com.sample.decision;

import org.jbpm.graph.exe.ExecutionContext;
import org.jbpm.graph.node.DecisionHandler;

public class SampleDecisionHandler implements DecisionHandler
{
 private static final long serialVersionUID = 1L;
 public String decide(ExecutionContext context) throws Exception
 {
 int budget = ((Number)context.getContextInstance().getVariable("status")).intValue();
 if (budget == 0) return "tr2";
 else if (budget == 1) return "tr3";
 else return "tr3";
 }
}


---------------------------------------- MY NEW CLASS ----------------------------------------


package com.sample.util;

import org.jbpm.graph.def.ProcessDefinition;
import org.jbpm.graph.exe.ProcessInstance;

public class StartProcess
{
 private String path = "";

 /** Creates a new instance of StartProcess */
 private StartProcess()
 {
 path = "C:\\Applications and Projects\\ECLIPSE Workspace\\Process Initiator\\src\\" +
 "process\\Initiator.par\\processdefinition.xml";
 }


 /** */
 public void init()
 {
 try
 {
 ProcessDefinition def = ProcessDefinition.parseXmlResource(path);
 System.out.println("STEP 1 - Istanziata la classe ProcessDefinition");

 ProcessInstance instance = new ProcessInstance(def);
 System.out.println("STEP 2 - Istanziata la classe ProcessInstance");

 instance.signal();
 System.out.println("STEP 3 - Effettuato il primo signal");
 }
 catch(Exception e)
 {
 System.err.println(e.getMessage());
 //e.printStackTrace();
 }
 }


 /** */
 public static void main(String[] args)
 {
 try
 {
 StartProcess sp = new StartProcess();
 System.out.println("STEP 0 - Istanziata la classe StartProcess");
 System.out.println(sp.path);
 sp.init();
 }
 catch(Exception exc)
 {
 System.err.println(exc.getMessage());
 exc.printStackTrace();
 }
 }
}

[fidalma]

Hi all,
I am always in trouble... sigh...
I have solved the previous stupid problem, but now I have another one.
This is the situation:

-------------------------------------- PROCESS DEFINITION --------------------------------------

<?xml version="1.0" encoding="UTF-8"?>
<process-definition xmlns="urn:jbpm.org:jpdl-3.1" name="Initiator">
 <swimlane name="initiator" />
 <start-state name="start new process">
 <task swimlane="process initiator" />
 <transition name="tr1" to="decision">
 <action name="action" class="com.sample.action.SampleActionHandler">
 </action>
 </transition>
 </start-state>
 <decision name="decision">
 <handler class="com.sample.decision.SampleDecisionHandler"></handler>
 <transition name="tr2" to="action"></transition>
 <transition name="tr3" to="end1"></transition>
 </decision>
 <state name="action">
 <transition name="tr4" to="end1"></transition>
 </state>
 <end-state name="end1"></end-state>
</process-definition>


---------------------------------------- MY ACTION HANDLER --------------------------------------


package com.sample.action;

import org.jbpm.graph.def.ActionHandler;
import org.jbpm.graph.exe.ExecutionContext;

public class SampleActionHandler implements ActionHandler
{
 private static final long serialVersionUID = 1L;
 public void execute(ExecutionContext context) throws Exception
 {
 Runtime rt = null;
 Process process = null;

 context.getContextInstance().createVariable("greeting", "Greeting from SampleActionHandler");
 try
 {
 rt = Runtime.getRuntime();
 process = rt.exec("C:\\Applications~1\\ECLIPSE~1\\Start.bat");
 context.getContextInstance().createVariable("status", new Integer(process.waitFor()));
 }
 catch (Exception e)
 {
 System.out.println(e);
 context.getContextInstance().createVariable("budget", new Integer(1));
 }
 }
}


------------------------------------- MY DECISION HANDLER --------------------------------------


package com.sample.decision;

import org.jbpm.graph.exe.ExecutionContext;
import org.jbpm.graph.node.DecisionHandler;

public class SampleDecisionHandler implements DecisionHandler
{
 private static final long serialVersionUID = 1L;
 public String decide(ExecutionContext context) throws Exception
 {
 int budget = ((Number)context.getContextInstance().getVariable("status")).intValue();
 if (budget == 0) return "tr2";
 else if (budget == 1) return "tr3";
 else return "tr3";
 }
}


---------------------------------------- MY NEW CLASS ----------------------------------------


package com.sample.util;

import org.jbpm.graph.def.ProcessDefinition;
import org.jbpm.graph.exe.ProcessInstance;

public class StartProcess
{
 private String path = "";

 /** Creates a new instance of StartProcess */
 private StartProcess()
 {
 path = "C:\\Applications and Projects\\ECLIPSE Workspace\\Process Initiator\\src\\" +
 "process\\Initiator.par\\processdefinition.xml";
 }


 public void init()
 {
 try
 {
 ProcessDefinition def = ProcessDefinition.parseXmlResource(path);
 System.out.println("STEP 1 - Istanziata la classe ProcessDefinition");

 ProcessInstance instance = new ProcessInstance(def);
 System.out.println("STEP 2 - Istanziata la classe ProcessInstance");

 instance.signal();
 System.out.println("STEP 3 - Effettuato il primo signal");
 }
 catch(Exception e)
 {
 System.err.println(e.getMessage());
 //e.printStackTrace();
 }
 }


 public static void main(String[] args)
 {
 try
 {
 StartProcess sp = new StartProcess();
 System.out.println("STEP 0 - Istanziata la classe StartProcess");
 System.out.println(sp.path);
 sp.init();
 }
 catch(Exception exc)
 {
 System.err.println(exc.getMessage());
 exc.printStackTrace();
 }
 }
}

When I try to execute my class "StartProcess" then I have the error "Couldn't parse process definition...". This is the output:

[java] STEP 0 - Istanziata la classe StartProcess
[java] C:\Applications and Projects\ECLIPSE Workspace\Process Initiator\src\process\Initiator.par\processdefinition.xml
[java] 11:46:44,190 [main] INFO JbpmConfiguration : using jbpm configuration resource 'jbpm.cfg.xml'
[java] 11:46:44,737 [main] DEBUG JbpmConfiguration : creating jbpm configuration from input stream
[java] 11:46:44,831 [main] ERROR JpdlXmlReader : couldn't parse process definition
[java] org.dom4j.DocumentException: null Nested exception: null
[java] at org.dom4j.io.SAXReader.read(SAXReader.java:484)
[java] at org.jbpm.jpdl.xml.JpdlParser.parse(JpdlParser.java:57)
[java] at org.jbpm.jpdl.xml.JpdlXmlReader.readProcessDefinition(JpdlXmlReader.java:138)
[java] at org.jbpm.graph.def.ProcessDefinition.parseXmlInputStream(ProcessDefinition.java:172)
[java] at org.jbpm.graph.def.ProcessDefinition.parseXmlResource(ProcessDefinition.java:153)
[java] at com.sample.util.StartProcess.init(StartProcess.java:22)
[java] at com.sample.util.StartProcess.main(StartProcess.java:47)
[java] Nested exception:
[java] [[ERROR] couldn't parse process definition]
[java] java.net.MalformedURLException
[java] at java.net.URL.(URL.java:571)
[java] at java.net.URL.(URL.java:434)
[java] at java.net.URL.(URL.java:383)
[java] at org.apache.xerces.impl.XMLEntityManager.setupCurrentEntity(Unknown Source)
[java] at org.apache.xerces.impl.XMLVersionDetector.determineDocVersion(Unknown Source)
[java] at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
[java] at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
[java] at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
[java] at org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source)
[java] at org.apache.xerces.jaxp.SAXParserImpl$JAXPSAXParser.parse(Unknown Source)
[java] at org.dom4j.io.SAXReader.read(SAXReader.java:465)
[java] at org.jbpm.jpdl.xml.JpdlParser.parse(JpdlParser.java:57)
[java] at org.jbpm.jpdl.xml.JpdlXmlReader.readProcessDefinition(JpdlXmlReader.java:138)
[java] at org.jbpm.graph.def.ProcessDefinition.parseXmlInputStream(ProcessDefinition.java:172)
[java] at org.jbpm.graph.def.ProcessDefinition.parseXmlResource(ProcessDefinition.java:153)
[java] at com.sample.util.StartProcess.init(StartProcess.java:22)
[java] at com.sample.util.StartProcess.main(StartProcess.java:47)


Could someone explain to me why I'm having this error and what do I have to do to solve it ?

Thank you very much in advance !!

Regards,
Fidalma
Italy


P.S. probably you will find two posts because I clicked "Submit" button twice instead of "Preview" button ... sorry...

[koen.aers]

Fidalma,

It says the URL is not found. You should put the processdefinition you want to read on the classpath if you want to use the ProcessDefinition.parseXmlResource() method.

Regards,
Koen