ArrayIndexOOB exception: org.hibernate.event.def.DefaultFlushEntityEventListener:checkNaturalId(), line 79 ---------------------------------------------------------------------------------------------------------- Key: HHH-1488 URL: http://opensource.atlassian.com/projects/hibernate/browse/HHH-1488 Project: Hibernate3 Issue Type: Bug Components: core Affects Versions: 3.1.2 Environment: Windows, Sun 1.5 JDK, Hibernate 3.1.2, Oracle 9i Reporter: Dave Nebinger The checkNaturalId() method has a bug. Basically it's using "loaded[prop]" in the isEqual() method call but it should be using "loaded[i]". The value for prop is the index into the array of properties for the entity where the natural key is. The value for i is the index in the loaded[] array that is being checked. In my case I've got a single natural key so loaded[0] equals the natural key value, but it is located at position 1 in the properties[15] array. The full line, "if ( !types[prop].isEqual( current[prop], loaded[prop], entityMode ) ) {" throws ArrayIndexOOB exception since prop is 1 but only loaded[0] (i) is valid. The fix is quite simple, just change the line to read: "if ( !types[prop].isEqual( current[prop], loaded[i], entityMode ) ) {"