[jboss-jira] [JBoss JIRA] Closed: (JBRULES-2267) NullPointerException would be thrown during rule execution

NullPointerException would be thrown during rule execution ---------------------------------------------------------- Key: JBRULES-2267 URL: https://jira.jboss.org/jira/browse/JBRULES-2267 Project: Drools Issue Type: Bug Security Level: Public(Everyone can see) Components: All Affects Versions: 5.0.1.FINAL Environment: Drools version: 5.0.1 JDK version: 1.5.0_6 Reporter: Freddy Andersen Assignee: Edson Tirelli Fix For: 5.1.0.M2 Attachments: ClassFieldAccessorStore.java, HelloWorld-1.drl, Message.java, Message.java, SerializedPackageMergeTest.java, SerializedPackageMergeTest.java NullPointerException would be thrown during rule execution when the following conditions were met: 1. The org.drools.rule.Package instances should be serialized/de-serialized before being added to the RuleBase. 2. The de-serialized package instances should be added to a RuleBase - all the packages have the same package name. 3. At least one of the rules in the packages (not in the first package to be added to the RulBase; it would work fine while in the first package) should contain an IN, or NOT IN operator. Our investigation revealed the followings: * One of the object field, ClassFieldReader. reader which is defined as transient, was let null when the package's were added to the RuleBase. * It became null because the parent package has been serialized/de-serialized. * It was not properly re-wired during the package merging when adding the package(s) to the RuleBase. * It only happens to the conditions/fields when IN or NOT IN was used. In other words, when a MultiRestrictionFieldConstraint was used. * The correct ReadAccessor was correctly set to instances of MultiRestrictionFieldConstraint in ClassFieldAccessorStore.merge, and the instance of ReadAccessor was propagated throw restrictions, such as OrCompositeRestriction during rule execution. The issue is that the leaf restrictions, such as LiteralRestriction, would only use their own ReadAccessor, not the one passed in, when evaluating isAllowed. Since it's own ReadAccessor was not properly re-set, meaning the field reader is null in this case, a NullPointerException would occur.