2 Replies Latest reply on Feb 13, 2014 11:15 AM by titupetrea

Problem compiling package, no valid constructor

jmiguel77 Nov 5, 2012 5:42 PM

I am trying to compile a package, the validation passes but the compilation gives me this error:

java.io.InvalidClassException: org.drools.base.field.ClassFieldImpl; org.drools.base.field.ClassFieldImpl; no valid constructor

I am attaching the source drl file and java classes

Thanks

1. Re: Problem compiling package, no valid constructor

titupetrea Feb 12, 2014 5:27 AM (in response to jmiguel77)

Hello,

I have the same problem with drools 5.6.0.FINAL

This is the code
public class KnowledgeBaseSerializationTest
{

    @Test
    public void test() throws IOException, ClassNotFoundException
    {
        KnowledgeBuilder kb = KnowledgeBuilderFactory.newKnowledgeBuilder();
        kb.add(ResourceFactory.newClassPathResource("drools/ActorEvent.drl"), ResourceType.DRL);
        kb.add(ResourceFactory.newClassPathResource("drools/Authorization.drl"), ResourceType.DRL);
        kb.add(ResourceFactory.newClassPathResource("drools/ConnectionAuthorizationReq.drl"), ResourceType.DRL);
        kb.add(ResourceFactory.newClassPathResource("drools/StatusUpdateEvt.drl"), ResourceType.DRL);
        kb.add(ResourceFactory.newClassPathResource("drools/Repository.drl"), ResourceType.DRL);
        if (kb.hasErrors())
        {
            for (KnowledgeBuilderError err : kb.getErrors())
            {
                System.out.println(err.getLines() + " " + err.getMessage());
            }
            throw new IllegalStateException("DRL errors");
        }

        KnowledgeBase wroteKnowledgeBase = KnowledgeBaseFactory.newKnowledgeBase();
        wroteKnowledgeBase.addKnowledgePackages(kb.getKnowledgePackages());
        File file = new File("target/serializedKnowledgeBase");

        // serialize KnowledgeBase
        try (ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(file)))
        {
            oos.writeObject(wroteKnowledgeBase);
            oos.flush();
        }

        // deserialize KnowledgeBase
        ObjectInputStream ois = new ObjectInputStream(new FileInputStream(file));
        KnowledgeBase readKnowledgeBase = (KnowledgeBase) ois.readObject();
    }
}

and the stacktrace:

java.io.InvalidClassException: org.drools.base.field.ClassFieldImpl; no valid constructor
    at java.io.ObjectStreamClass$ExceptionInfo.newInvalidClassException(ObjectStreamClass.java:147)
    at java.io.ObjectStreamClass.checkDeserialize(ObjectStreamClass.java:755)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1751)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1347)
    at java.io.ObjectInputStream.readObject(ObjectInputStream.java:369)
    at org.drools.rule.constraint.MvelConstraint.readExternal(MvelConstraint.java:479)
    at java.io.ObjectInputStream.readExternalData(ObjectInputStream.java:1810)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1769)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1347)
    at java.io.ObjectInputStream.readObject(ObjectInputStream.java:369)
    at java.util.ArrayList.readObject(ArrayList.java:733)
    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:601)
    at java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:1004)
    at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1866)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1771)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1347)
    at java.io.ObjectInputStream.readObject(ObjectInputStream.java:369)
    at org.drools.rule.Pattern.readExternal(Pattern.java:125)
    at java.io.ObjectInputStream.readExternalData(ObjectInputStream.java:1810)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1769)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1347)
    at java.io.ObjectInputStream.readObject(ObjectInputStream.java:369)
    at java.util.ArrayList.readObject(ArrayList.java:733)
    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:601)
    at java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:1004)
    at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1866)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1771)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1347)
    at java.io.ObjectInputStream.readObject(ObjectInputStream.java:369)
    at org.drools.rule.GroupElement.readExternal(GroupElement.java:63)
    at java.io.ObjectInputStream.readExternalData(ObjectInputStream.java:1810)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1769)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1347)
    at java.io.ObjectInputStream.readObject(ObjectInputStream.java:369)
    at org.drools.rule.Rule.readExternal(Rule.java:186)
    at java.io.ObjectInputStream.readExternalData(ObjectInputStream.java:1810)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1769)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1347)
    at java.io.ObjectInputStream.readObject(ObjectInputStream.java:369)
    at org.drools.rule.JavaDialectRuntimeData.readExternal(JavaDialectRuntimeData.java:196)
    at java.io.ObjectInputStream.readExternalData(ObjectInputStream.java:1810)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1769)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1347)
    at java.io.ObjectInputStream.readObject(ObjectInputStream.java:369)
    at java.util.HashMap.readObject(HashMap.java:1043)
    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:601)
    at java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:1004)
    at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1866)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1771)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1347)
    at java.io.ObjectInputStream.readObject(ObjectInputStream.java:369)
    at org.drools.rule.DialectRuntimeRegistry.readExternal(DialectRuntimeRegistry.java:58)
    at java.io.ObjectInputStream.readExternalData(ObjectInputStream.java:1810)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1769)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1347)
    at java.io.ObjectInputStream.readObject(ObjectInputStream.java:369)
    at org.drools.rule.Package.readExternal(Package.java:212)
    at java.io.ObjectInputStream.readExternalData(ObjectInputStream.java:1810)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1769)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1347)
    at java.io.ObjectInputStream.readObject(ObjectInputStream.java:369)
    at java.util.HashMap.readObject(HashMap.java:1043)
    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:601)
    at java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:1004)
    at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1866)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1771)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1347)
    at java.io.ObjectInputStream.readObject(ObjectInputStream.java:369)
    at org.drools.common.AbstractRuleBase.readExternal(AbstractRuleBase.java:304)
    at org.drools.reteoo.ReteooRuleBase.readExternal(ReteooRuleBase.java:226)
    at org.drools.impl.KnowledgeBaseImpl.readExternal(KnowledgeBaseImpl.java:121)
    at java.io.ObjectInputStream.readExternalData(ObjectInputStream.java:1810)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1769)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1347)
    at java.io.ObjectInputStream.readObject(ObjectInputStream.java:369)
    at com.keba.kemove.cpm.drools.KnowledgeBaseSerializationTest.test(KnowledgeBaseSerializationTest.java:56)

The exception is thrown at deserialization
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2. Re: Problem compiling package, no valid constructor

titupetrea Feb 13, 2014 11:15 AM (in response to jmiguel77)

The problem is my case was that I had a condition like this:
$processEntry: ProcessEntry
    (
        rcvdMessage.extensionClass == Messages.StatusUpdateEvt.class &&
        ((StatusUpdateEvt)rcvdMessage.expectExtension(Messages.StatusUpdateEvt.class)).status.wallboxPlugStatus.vehiclePlugged == true
    )

extensionClass on attribute rcvdMessage is of type Class and when I serialized the KnowledgeBase, drools used the class org.drools.base.field.ClassFieldImpl.
The solution was to write a method to test if extensionClass equals a Class (passed the class compared to as an argument):

$processEntry: ProcessEntry
    (
        rcvdMessage.isExtensionClass(Messages.StatusUpdateEvt.class) &&
        ((StatusUpdateEvt)rcvdMessage.expectExtension(Messages.StatusUpdateEvt.class)).status.wallboxPlugStatus.vehiclePlugged == true
    )

public boolean isExtensionClass(Class cls)
{
     return cls.equals(extensionClass);
}
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