[hibernate-issues] [Hibernate-JIRA] Commented: (HHH-2598) Mapping a collection of entities from two different classes with the same collection name results in duplicate backref property exception if collection keys are not null

Mapping a collection of entities from two different classes with the same collection name results in duplicate backref property exception if collection keys are not null ------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Key: HHH-2598 URL: http://opensource.atlassian.com/projects/hibernate/browse/HHH-2598 Project: Hibernate3 Issue Type: Bug Components: core Affects Versions: 3.2.1, 3.2.2, 3.2.3 Environment: Proven on Hibernate 3.2.2 and 3.2.3, PostgreSQL 8.2.3, WindowsXP, Java 1.5 Reporter: Guido Scalise Attachments: backref.patch, Hibernate-bug.zip Mapping a child entity collection from two different parent entities results in duplicate backref property exception when configuring the session factory if the collection keys are marked not null and the collection names are the same in both parents. Log is: (cfg.Environment 509 ) Hibernate 3.2.3 (cfg.Environment 542 ) hibernate.properties not found (cfg.Environment 676 ) Bytecode provider name : cglib (cfg.Environment 593 ) using JDK 1.4 java.sql.Timestamp handling (cfg.Configuration 1426) configuring from resource: /hibernate.cfg.xml (cfg.Configuration 1403) Configuration resource: /hibernate.cfg.xml (cfg.Configuration 553 ) Reading mappings from resource : com/bbsw/tests/ParentA.hbm.xml (cfg.HbmBinder 300 ) Mapping class: com.bbsw.tests.ParentA -> PARENT_A (cfg.Configuration 553 ) Reading mappings from resource : com/bbsw/tests/ParentB.hbm.xml (cfg.HbmBinder 300 ) Mapping class: com.bbsw.tests.ParentB -> PARENT_B (cfg.Configuration 553 ) Reading mappings from resource : com/bbsw/tests/Child.hbm.xml (cfg.HbmBinder 300 ) Mapping class: com.bbsw.tests.Child -> CHILD (cfg.Configuration 1541) Configured SessionFactory: null (cfg.HbmBinder 2375) Mapping collection: com.bbsw.tests.ParentA.children -> CHILD (cfg.HbmBinder 2375) Mapping collection: com.bbsw.tests.ParentB.children -> CHILD Exception in thread "main" org.hibernate.MappingException: Duplicate property mapping of _childrenBackref found in com.bbsw.tests.Child at org.hibernate.mapping.PersistentClass.checkPropertyDuplication(PersistentClass.java:459) at org.hibernate.mapping.PersistentClass.validate(PersistentClass.java:449) at org.hibernate.mapping.RootClass.validate(RootClass.java:192) at org.hibernate.cfg.Configuration.validate(Configuration.java:1102) at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1287) at HBTest.main(HBTest.java:17) The problem seems to be originated during the second Collection binding pass in org.hibernate.cfg.HbmBinder, as the Backrefs and IndexBackrefs names are created like this: (Excerpts from HbmBinder.java r10921 2006-12-05 14:39:12Z steve.ebersole(a)jboss.com, contained in the Hibernate 3.2.3.ga source) line 2242: IndexBackref ib = new IndexBackref(); line 2243: ib.setName( '_' + node.attributeValue( "name" ) + "IndexBackref" ); and line 2478: Backref prop = new Backref(); line 2479: prop.setName( '_' + node.attributeValue( "name" ) + "Backref" ); in both cases the node name value is the collection name. So for every collection that points to a child, Hibernate creates a backref property without considering the posibility of more than one entity declaring the same collection name. I've patched the code to add the collection owner's entity name to the property name, and it worked without problems. I'm attaching: * ParentA, ParentB and Child classes * Mappings for ParentA, ParentB and Child * hbm.xml file * Main test case. (HBTest.java) * Proposed patch in unified diff format.