setting classloader in CGLIB class generators --------------------------------------------- Key: HHH-1131 URL: http://opensource.atlassian.com/projects/hibernate/browse/HHH-1131 Project: Hibernate3 Issue Type: Improvement Components: core Affects Versions: 3.0.5 Environment: Hibernate 3.0.5, Oracle 10 Reporter: Moshe Ben Shoham In my application I am loading plug-ins mapping documents and persistent classes from jars using some UrlClassLoaders (one per plugin). I then set the threadContextClassLoader to be the CompositeClassLoader that holds all those UrlClassLoaders. Everything works fine until I add a proxy to one of the mapping document (I simplified the names a little): <hibernate-mapping> <subclass name="myplugin.MyExtension" discriminator-value="3" proxy="myplugin.IMyExtension" extends="core.MyBasicClass" > <join table="MY_EXTENSION"> <key column="ENTITY_ID"/> <property name="extraNumData" column="EXTRA_NUM_DATA" type="long"/> <property name="extraStrData" column="EXTRA_STR_DATA" type="string"/> </join> </subclass > </hibernate-mapping> See below the exception I get. Hibernate uses net.sf.cglib.proxy.Enhancer as the class generator in CGLIBLazyInitializer.getProxyFactory(). Now, it seeme like CGLIB allows customizing the ClassLoader used by its class generators using the method net.sf.cglib.core.AbstractClassGenerator.setClassLoader() (Enhancer extends AbstractClassGenerator). But, it doesn't seem like it is possible to use it in Hibernate, because this is how the Enhancer is used in CGLIBLazyInitializer.getProxyFactory() : return (Factory) Enhancer.create( (interfaces.length==1) ? persistentClass : null, interfaces, NULL_METHOD_INTERCEPTOR ); If I replace it with the following code, it works: Enhancer e = new Enhancer(); e.setSuperclass((interfaces.length==1) ? persistentClass : null); e.setInterfaces(interfaces); e.setCallback(NULL_METHOD_INTERCEPTOR); e.setClassLoader(Thread.currentThread().getContextClassLoader()); // this is the addition! return (Factory)e.create(); Is there any other way I can do it (I know I can implement my own persister, but it seems like there's too much code that needs to be overridden...)? Is there any planned enhancement regarding this issue? Full stack trace of any exception that occurs: CGLIB Enhancement failed: com.octavian.fas.domain.business.BusinessTransaction net.sf.cglib.core.CodeGenerationException: java.lang.reflect.InvocationTargetException-->null at net.sf.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:236) at net.sf.cglib.proxy.Enhancer.createHelper(Enhancer.java:373) at net.sf.cglib.proxy.Enhancer.create(Enhancer.java:281) at net.sf.cglib.proxy.Enhancer.create(Enhancer.java:640) at org.hibernate.proxy.CGLIBLazyInitializer.getProxyFactory(CGLIBLazyInitializer.java:94) at org.hibernate.proxy.CGLIBProxyFactory.postInstantiate(CGLIBProxyFactory.java:42) at org.hibernate.tuple.PojoTuplizer.buildProxyFactory(PojoTuplizer.java:144) at org.hibernate.tuple.AbstractTuplizer.<init>(AbstractTuplizer.java:83) at org.hibernate.tuple.PojoTuplizer.<init>(PojoTuplizer.java:54) at org.hibernate.tuple.TuplizerLookup.create(TuplizerLookup.java:47) at org.hibernate.tuple.EntityMetamodel.<init>(EntityMetamodel.java:218) at org.hibernate.persister.entity.BasicEntityPersister.<init>(BasicEntityPersister.java:400) at org.hibernate.persister.entity.SingleTableEntityPersister.<init>(SingleTableEntityPersister.java:104) at org.hibernate.persister.PersisterFactory.createClassPersister(PersisterFactory.java:55) at org.hibernate.impl.SessionFactoryImpl.<init>(SessionFactoryImpl.java:211) at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1005) at org.springframework.orm.hibernate3.LocalSessionFactoryBean.newSessionFactory(LocalSessionFactoryBean.java:777) at org.springframework.orm.hibernate3.LocalSessionFactoryBean.afterPropertiesSet(LocalSessionFactoryBean.java:703) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1058) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:363) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:226) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:147) at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:269) at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:318) at com.octavian.sma.analytical.batch.SpringHelper.init(SpringHelper.java:77) at com.octavian.sma.analytical.batch.SpringHelper.<init>(SpringHelper.java:38) at com.octavian.sma.analytical.batch.dailynongrouping.DailyNonGroupingAnalyticalBatch.initSpringHelper(DailyNonGroupingAnalyticalBatch.java:44) at com.octavian.sma.analytical.batch.AnalyticalBatch.run(AnalyticalBatch.java:58) at com.octavian.sma.analytical.batch.dailynongrouping.DailyNonGroupingAnalyticalBatch.main(DailyNonGroupingAnalyticalBatch.java:29) Caused by: java.lang.reflect.InvocationTargetException at sun.reflect.GeneratedMethodAccessor3.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:585) at net.sf.cglib.core.ReflectUtils.defineClass(ReflectUtils.java:373) at net.sf.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:218) ... 28 more Caused by: java.lang.NoClassDefFoundError: myplugin/IMyBusinessTransactionExtension at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(ClassLoader.java:620) ... 33 more