Philip McWilliams created DROOLS-778: ---------------------------------------- Summary: Deserialization error: java.io.InvalidClassException: org.drools.base.evaluators.StrEvaluatorDefinition$StrEvaluator; no valid constructor Key: DROOLS-778 URL: https://issues.jboss.org/browse/DROOLS-778 Project: Drools Issue Type: Bug Components: core engine Affects Versions: 5.5.0.Final Environment: Windows 7; Java 6; Drools 5.5.0.Final (incl. drools-core, drools-compiler, drools-spring and drools-camel) Reporter: Philip McWilliams Assignee: Mario Fusco I am seeking to compile rules at build-time and then save (serialize) the output to disk. At deployment, I then wish to build a knowledge base from the deserialized knowledge packages (rather than by re-compiling the source rules files). In general this works ... unless I use the "str" operator in an LHS. This operator is implemented by the *org.drools.base.evaluators.StrEvaluatorDefinition$StrEvaluator* class and this class does not appear to deserialize properly. A round trip exercise on my local machine always fails with this error: {code} java.io.InvalidClassException: org.drools.base.evaluators.StrEvaluatorDefinition$StrEvaluator; org.drools.base.evaluators.StrEvaluatorDefinition$StrEvaluator; no valid constructor {code} My serialization/deserialization code is standard ... to serialize: {code} private void saveOutput(KnowledgeBuilder kbuilder) throws IOException { Collection<KnowledgePackage> kpkgs = kbuilder.getKnowledgePackages(); String outputFilename = outputFile == null ? "" : outputFile.trim(); if (outputFilename.isEmpty()) { outputFilename = project.getBasedir() + "target/classes/drools.drlx"; } ObjectOutputStream out = null; try { getLog().info("Saving compiled Drools output to " + outputFilename); out = new ObjectOutputStream(new FileOutputStream(outputFilename)); out.writeObject(kpkgs); } finally { if (out != null) { out.close(); } } } {code} ... to deserialize: {code} private Collection<KnowledgePackage> deserializeKnowledgePackages(Resource[] knowledgePackageObjects) throws IOException, ClassNotFoundException { Collection<KnowledgePackage> knowledgePackages = new ArrayList<KnowledgePackage>(); for (Resource knowledgePackageObject : knowledgePackageObjects) { LOG.info("Deserializing pre-compiled package " + knowledgePackageObject.getFilename()); ObjectInputStream in = null; try { in = new ObjectInputStream(knowledgePackageObject.getInputStream()); // The input stream might contain an individual package or a collection. knowledgePackages.addAll((Collection<KnowledgePackage>) in.readObject()); } finally { if (in != null) { in.close(); } } } return knowledgePackages; } {code} My workaround is to avoid using the "str" operator. *Apologies*: I have *not* checked version 6.2.0.Final because I have not yet worked out what versions of the Drools Spring and Camel modules to use (for 5.5.0.Final they were all versioned identically). -- This message was sent by Atlassian JIRA (v6.3.15#6346)