[rules-users] KnowledgeAgent exception

[Claus Straube]

Hi all,

I'm trying to use the resource scanner in my application (drools 5.1.1, 
also tried in 5.2.0-SNAPSHOT):

--snip--
         //resource scanner
         KnowledgeAgent kagent = 
KnowledgeAgentFactory.newKnowledgeAgent( "MyAgent" );
         kagent.applyChangeSet( 
ResourceFactory.newByteArrayResource(this.getChangeConfiguration()) );
         KnowledgeBase kbase = kagent.getKnowledgeBase();

         this.ksession = kbase.newStatefulKnowledgeSession();
--snip--

and getting always a 'KnowledgeAgent exception while trying to 
deserialize KnowledgeDefinitionsPackage' (see stacktrace below). Of 
course I've googled for the problem and found that it was in 5.0.1 a 
incompatibility problem between drools expert and guvner. But I'm not 
using guvnor at all. I want to place some *.drl files in a directory and 
run an agent that automatically updates my knowledge base. The agent 
finds the directory and the files, but has problems to deserialize them. 
If I'm loading them directly into the knowledge base they will work fine.

Any hints to find a solution are welcome.

Best regards - Claus


-----
java.lang.RuntimeException: KnowledgeAgent exception while trying to 
deserialize KnowledgeDefinitionsPackage
     at 
org.drools.agent.impl.KnowledgeAgentImpl.createPackageFromResource(KnowledgeAgentImpl.java:732)
     at 
org.drools.agent.impl.KnowledgeAgentImpl.addResourcesToKnowledgeBase(KnowledgeAgentImpl.java:965)
     at 
org.drools.agent.impl.KnowledgeAgentImpl.rebuildResources(KnowledgeAgentImpl.java:774)
     at 
org.drools.agent.impl.KnowledgeAgentImpl.buildKnowledgeBase(KnowledgeAgentImpl.java:646)
     at 
org.drools.agent.impl.KnowledgeAgentImpl.applyChangeSet(KnowledgeAgentImpl.java:190)
     at 
org.drools.agent.impl.KnowledgeAgentImpl.applyChangeSet(KnowledgeAgentImpl.java:172)
     at 
com.catify.core.process.routers.DecisionRouter.<init>(DecisionRouter.java:32)
     at 
com.catify.core.rest.TestDecisionRouter.testRouting(TestDecisionRouter.java:27)
     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
     at 
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
     at 
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
     at java.lang.reflect.Method.invoke(Method.java:616)
     at junit.framework.TestCase.runTest(TestCase.java:168)
     at junit.framework.TestCase.runBare(TestCase.java:134)
     at org.apache.camel.test.TestSupport.runBare(TestSupport.java:65)
     at junit.framework.TestResult$1.protect(TestResult.java:110)
     at junit.framework.TestResult.runProtected(TestResult.java:128)
     at junit.framework.TestResult.run(TestResult.java:113)
     at junit.framework.TestCase.run(TestCase.java:124)
     at junit.framework.TestSuite.runTest(TestSuite.java:232)
     at junit.framework.TestSuite.run(TestSuite.java:227)
     at 
org.junit.internal.runners.JUnit38ClassRunner.run(JUnit38ClassRunner.java:83)
     at 
org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:46)
     at 
org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
     at 
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
     at 
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
     at 
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
     at 
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Caused by: java.io.StreamCorruptedException: invalid stream header: 7061636B
     at 
java.io.ObjectInputStream.readStreamHeader(ObjectInputStream.java:800)
     at java.io.ObjectInputStream.<init>(ObjectInputStream.java:297)
     at 
org.drools.common.DroolsObjectInputStream.<init>(DroolsObjectInputStream.java:71)
     at 
org.drools.core.util.DroolsStreamUtils.streamIn(DroolsStreamUtils.java:205)
     at 
org.drools.core.util.DroolsStreamUtils.streamIn(DroolsStreamUtils.java:174)
     at 
org.drools.agent.impl.KnowledgeAgentImpl.createPackageFromResource(KnowledgeAgentImpl.java:721)
     ... 27 more