On 03.04.2010 00:40, Amit Kumar wrote: Hi, from what we figured out at work, they're just plain serialized knowledge packages (or rather, collections thereof). IIRC, this is also described somewhere in the docs. So all you need to do is: - create the knowledge packages in-memory using the normal KnowledgeBuilder api calls (loads of documentation available for this) - use java object serialization to write a Collection<KnowledgePackage> into a file. Upon loading these packages, make sure all the classes used/imported in the *.drl files are available on the classpath, otherwise you probably won't be able to deserialize the packages. Kind regards Ansgar

Did you actually get this to work? I have tried both ways to create a .PKG mentioned here and still haven't got it to work. FILE CREATION CODE (Commented out portions are for direct serialization): public static void createPKG(Collection<KnowledgePackage> kpkgs, File file) throws IOException, FileNotFoundException { FileOutputStream fos = null; ObjectOutputStream out = null; fos = new FileOutputStream(file); out = new ObjectOutputStream(fos); try { //out.writeObject(kpkgs); DroolsStreamUtils.streamOut(fos, kpkgs); } catch (IOException e) { String error ="Could not serialize object!"; logger.error(error); throw new DroolsPKGCreatorException(error,e); } finally { try { //out.close(); fos.close(); } catch (IOException e) { logger.error("Could not close stream during serialization!",e); } } } KBASE CREATION FROM PKG KnowledgeAgent kagent = KnowledgeAgentFactory.newKnowledgeAgent( "MyKnowledgeAgent" ); kagent.applyChangeSet(ResourceFactory.newClassPathResource(/* file created from above method */)); KnowledgeBase kbase = kagent.getKnowledgeBase(); Am I doing something wrong? Thanks for the help! -- View this message in context: http://drools-java-rules-engine.46999.n3.nabble.com/creating-pkg-from-drl... Sent from the Drools - User mailing list archive at Nabble.com.

I've tried to clean up my testing to be sure and created a few different scenarios. All of them end with the same result: java.lang.ClassCastException: [B at org.drools.rule.Package.readExternal(Package.java:197) at org.drools.definitions.impl.KnowledgePackageImp.readExternal(KnowledgePackageImp.java:99) at java.io.ObjectInputStream.readExternalData(ObjectInputStream.java:1756) at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1717) at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1305) at java.io.ObjectInputStream.readObject(ObjectInputStream.java:348) at java.util.ArrayList.readObject(ArrayList.java:591) 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 java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:946) at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1812) at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1719) at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1305) at java.io.ObjectInputStream.readObject(ObjectInputStream.java:348) at org.drools.core.util.DroolsStreamUtils.streamIn(DroolsStreamUtils.java:189) at org.drools.core.util.DroolsStreamUtils.streamIn(DroolsStreamUtils.java:173) at org.drools.compiler.PackageBuilder.addKnowledgeResource(PackageBuilder.java:488) at org.drools.builder.impl.KnowledgeBuilderImpl.add(KnowledgeBuilderImpl.java:28) I am serializing Collection<KnowledgePackage> to a file (.pkg). I get the same error whether I: - Create a KAgent from a changeset pointing to the .pkg - Add a changset resource pointing to the .pkg to a KBuilder - Add the pkg directly to the KBuilder I have verified that if I manually deserialize the object from the file, it successfully deserializes to the Collection<KnowledgePackage>. -- View this message in context: http://drools-java-rules-engine.46999.n3.nabble.com/creating-pkg-from-drl... Sent from the Drools - User mailing list archive at Nabble.com.

Try to add all the packages to a kbuilder and then serialize the resulting packages. You will need to create a PKG per logical package though. If your DSLR and DSL files are in the same logical package, the kbuilder will only contain one package that you have to serialize. Best, XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX Esteban Aliverti - Developer @ http://www.plugtree.com - Blog @ http://ilesteban.wordpress.com On Thu, Aug 5, 2010 at 12:08 PM, jrob <josh.roberts(a)cerner.com&gt; wrote:

Ok, did that and it still only works when serializing using DroolsStreamUtils.streamOut and using a KnowledgeAgent to construct the KnowledgeBase from the serialized package, but it does work with multiple resources in the same logical package when serializing. Still fails when trying to use KnowledgeBuilder. -- View this message in context: http://drools-java-rules-engine.46999.n3.nabble.com/creating-pkg-from-drl... Sent from the Drools - User mailing list archive at Nabble.com.