[hibernate-issues] [Hibernate-JIRA] Commented: (HHH-3719) Javassist fails to instrument valid classes in certain cases

Javassist fails to instrument valid classes in certain cases ------------------------------------------------------------ Key: HHH-3719 URL: http://opensource.atlassian.com/projects/hibernate/browse/HHH-3719 Project: Hibernate Core Issue Type: Bug Components: core Affects Versions: 3.3.1 Environment: Javassist 3.4.GA (also tested with 3.9.GA) Reporter: Paul Pogonyshev Priority: Minor In certain cases Javassist fails with the following message: "duplicate method: getId in org.hibernate.proxy.HibernateProxy_$$_javassist_0". I was able to trace the problem down to the following simple case. public interface Identifiable <Type> { Type getId (); } public interface Entity extends Identifiable <Long> { Long getId (); } public class EntityImpl implements Entity { private Long id; public Long getId () { return id; } void setId (Long id) { this.id = id; } } <?xml version="1.0"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> <hibernate-mapping> <class name="EntityImpl" proxy="Entity"> <id name="id"/> </class> </hibernate-mapping> Note that at least generics in definition of Identifiable interface and specifying proxy interface in the mapping seems important. Easy workaround seems to just not explicitly redefine getId() in Entity interface, i.e. just keep the one (same one) gotten from Identifiable. However, _finding_ this workaround was by no means easy. As I know, Java compiler removes generics information from compiled code, so the two methods might indeed appear different (i.e. as Objecte getId() and Long getId() correspondingly). Maybe Javassist could just disable duplicate method checks in generated classes for the cases when _both_ methods come from the wrapped class? I'm not sure this is the right tracker, but I couldn't find one for Javassist.