2 Replies Latest reply on Sep 18, 2008 1:38 PM by Shigeru Chiba

    NullPointerException in RuntimeSupport.DefaultMethodHandler.

    Patrick Taylor Newbie

      I'm using javassist-3.8.1.GA with hibernate-core-3.3.0.SP1. I have a javassist problem that appears to occur when two different threads are doing a JavassistLazyInitializer.getProxy() on the exact same entity class + id but in two different sessions. One of the threads ends up in RuntimeSupport.DefaultMethodHandler.invoke() with the "proceed" argument set to null, which results in a NullPointerException. According to the javadoc for MethodHandler.invoke(), the proceed argument "is null if the overridden mehtod is abstract or declared in the interface", so I'm not sure why DefaultMethodHandler.invoke() doesn't check for null. But my guess is that there's some sort of race condition causing this.

      Here's one thing that might provide a clue: JavassistLazyInitializer.getProxy() is calling Class.newInstance() to create a new instance of my entity class (Carrier). The failure happens when a final field is being initialized during construction of that instance. The final field is declared in an abstract parent class (AbstractCodeParentEntity), and is initialized by calling an inherited method (createStringFieldValue). In other words, my Carrier entity inherits this field:

      private final FieldValue code = createStringFieldValue("code");

      This failure always occurs when createStringFieldValue is executing, so perhaps that provides a clue as to why the "proceed" argument ends up being null.

      Please let me know what other information I can provide to help diagnose the problem and whether you can suggest any workarounds.

      Below I've included the stack of the two threads that were simultaneously suspended by a setting a conditional breakpoint in Eclipse when proceed == null. The first is the thread that hit the breakpoint.


      Thread [btpool0-0] (Suspended (breakpoint at line 37 in RuntimeSupport$DefaultMethodHandler))
      RuntimeSupport$DefaultMethodHandler.invoke(Object, Method, Method, Object[]) line: 37
      Carrier_$$_javassist_70.createStringFieldValue(String) line: not available
      Carrier_$$_javassist_70(AbstractCodeParentEntity).() line: 17
      Carrier_$$_javassist_70(Organization).() line: 54
      Carrier_$$_javassist_70(Carrier).() line: 17
      Carrier_$$_javassist_70.() line: not available
      NativeConstructorAccessorImpl.newInstance0(Constructor, Object[]) line: not available [native method]
      NativeConstructorAccessorImpl.newInstance(Object[]) line: 39
      DelegatingConstructorAccessorImpl.newInstance(Object[]) line: 27
      Constructor.newInstance(Object...) line: 513
      Class.newInstance0() line: 355
      Class.newInstance() line: 308
      JavassistLazyInitializer.getProxy(Class, String, Class, Class[], Method, Method, AbstractComponentType, Serializable, SessionImplementor) line: 139
      JavassistProxyFactory.getProxy(Serializable, SessionImplementor) line: 72
      PojoEntityTuplizer(AbstractEntityTuplizer).createProxy(Serializable, SessionImplementor) line: 402
      JoinedSubclassEntityPersister(AbstractEntityPersister).createProxy(Serializable, SessionImplementor) line: 3483
      DefaultLoadEventListener.createProxyIfNecessary(LoadEvent, EntityPersister, EntityKey, LoadEventListener$LoadType, PersistenceContext) line: 298
      DefaultLoadEventListener.proxyOrLoad(LoadEvent, EntityPersister, EntityKey, LoadEventListener$LoadType) line: 219
      DefaultLoadEventListener.onLoad(LoadEvent, LoadEventListener$LoadType) line: 126
      SessionImpl.fireLoad(LoadEvent, LoadEventListener$LoadType) line: 905
      SessionImpl.internalLoad(String, Serializable, boolean, boolean) line: 873
      ManyToOneType(EntityType).resolveIdentifier(Serializable, SessionImplementor) line: 590
      ManyToOneType(EntityType).resolve(Object, SessionImplementor, Object) line: 412
      TwoPhaseLoad.initializeEntity(Object, boolean, SessionImplementor, PreLoadEvent, PostLoadEvent) line: 139
      EntityLoader(Loader).initializeEntitiesAndCollections(List, Object, SessionImplementor, boolean) line: 877
      EntityLoader(Loader).doQuery(SessionImplementor, QueryParameters, boolean) line: 752
      EntityLoader(Loader).doQueryAndInitializeNonLazyCollections(SessionImplementor, QueryParameters, boolean) line: 259
      EntityLoader(Loader).loadEntity(SessionImplementor, Object, Type, Object, String, Serializable, EntityPersister) line: 1881
      EntityLoader(AbstractEntityLoader).load(SessionImplementor, Object, Object, Serializable) line: 71
      EntityLoader(AbstractEntityLoader).load(Serializable, Object, SessionImplementor) line: 65
      SingleTableEntityPersister(AbstractEntityPersister).load(Serializable, Object, LockMode, SessionImplementor) line: 3072
      DefaultLoadEventListener.loadFromDatasource(LoadEvent, EntityPersister, EntityKey, LoadEventListener$LoadType) line: 434
      DefaultLoadEventListener.doLoad(LoadEvent, EntityPersister, EntityKey, LoadEventListener$LoadType) line: 415
      DefaultLoadEventListener.load(LoadEvent, EntityPersister, EntityKey, LoadEventListener$LoadType) line: 165
      DefaultLoadEventListener.proxyOrLoad(LoadEvent, EntityPersister, EntityKey, LoadEventListener$LoadType) line: 223
      DefaultLoadEventListener.onLoad(LoadEvent, LoadEventListener$LoadType) line: 126
      SessionImpl.fireLoad(LoadEvent, LoadEventListener$LoadType) line: 905
      SessionImpl.get(String, Serializable) line: 842
      SessionImpl.get(Class, Serializable) line: 835
      FullTextSessionImpl.get(Class, Serializable) line: 335
      HivemindFullTextSessionWrapper.get(Class, Serializable) line: 302
      $FullTextSession_11c689001bf.get(Class, Serializable) line: not available
      $FullTextSession_11c689001c0.get(Class, Serializable) line: not available
      BusinessServiceImpl.getById(Long, Class) line: 257
      $BusinessService_11c6890013b.getById(Long, Class) line: not available
      $BusinessService_11c6890013a.getById(Long, Class) line: not available
      EligibilityListenerImpl(AbstractMessageListener).receiveMessage(Reader) line: 134
      $EligibilityListener_11c68900134.receiveMessage(Reader) line: not available
      $EligibilityListener_11c68900133.receiveMessage(Reader) line: not available
      MessageListenerServlet.handlePost(HttpServletRequest, HttpServletResponse) line: 90
      MessageListenerServlet(AbstractHttpServlet).doPost(HttpServletRequest, HttpServletResponse) line: 99
      MessageListenerServlet(HttpServlet).service(HttpServletRequest, HttpServletResponse) line: 727
      MessageListenerServlet(HttpServlet).service(ServletRequest, ServletResponse) line: 820
      ServletHolder.handle(ServletRequest, ServletResponse) line: 487
      ServletHandler$CachedChain.doFilter(ServletRequest, ServletResponse) line: 1097
      HiveMindFilter(HiveMindFilter).doFilter(ServletRequest, ServletResponse, FilterChain) line: 172
      ServletHandler$CachedChain.doFilter(ServletRequest, ServletResponse) line: 1088
      ServletHandler.handle(String, HttpServletRequest, HttpServletResponse, int) line: 360
      SecurityHandler.handle(String, HttpServletRequest, HttpServletResponse, int) line: 216
      SessionHandler.handle(String, HttpServletRequest, HttpServletResponse, int) line: 181
      WebAppContext(ContextHandler).handle(String, HttpServletRequest, HttpServletResponse, int) line: 729
      WebAppContext.handle(String, HttpServletRequest, HttpServletResponse, int) line: 405
      Server(HandlerWrapper).handle(String, HttpServletRequest, HttpServletResponse, int) line: 152
      Server.handle(HttpConnection) line: 324
      HttpConnection.handleRequest() line: 505
      HttpConnection$RequestHandler.content(Buffer) line: 843
      HttpParser.parseNext() line: 647
      HttpParser.parseAvailable() line: 211
      HttpConnection.handle() line: 380
      SelectChannelConnector$ConnectorEndPoint(SelectChannelEndPoint).run() line: 395
      QueuedThreadPool$PoolThread.run() line: 488

      Thread [btpool0-2] (Suspended)
      Class.getDeclaredMethods0(boolean) line: not available [native method]
      Class.privateGetDeclaredMethods(boolean) line: 2427
      Class.getDeclaredMethods() line: 1791
      SecurityActions.getDeclaredMethods(Class) line: 29
      RuntimeSupport.findMethod2(Class, String, String) line: 106
      RuntimeSupport.findMethod(Object, String, String) line: 48
      Carrier_$$_javassist_70.createStringFieldValue(String) line: not available
      Carrier_$$_javassist_70(AbstractCodeParentEntity).() line: 17

      Carrier_$$_javassist_70(Organization).() line: 54
      Carrier_$$_javassist_70(Carrier).() line: 17
      Carrier_$$_javassist_70.() line: not available
      NativeConstructorAccessorImpl.newInstance0(Constructor, Object[]) line: not available [native method]
      NativeConstructorAccessorImpl.newInstance(Object[]) line: 39
      DelegatingConstructorAccessorImpl.newInstance(Object[]) line: 27
      Constructor.newInstance(Object...) line: 513
      Class.newInstance0() line: 355
      Class.newInstance() line: 308
      JavassistLazyInitializer.getProxy(Class, String, Class, Class[], Method, Method, AbstractComponentType, Serializable, SessionImplementor) line: 139
      JavassistProxyFactory.getProxy(Serializable, SessionImplementor) line: 72
      PojoEntityTuplizer(AbstractEntityTuplizer).createProxy(Serializable, SessionImplementor) line: 402
      JoinedSubclassEntityPersister(AbstractEntityPersister).createProxy(Serializable, SessionImplementor) line: 3483
      DefaultLoadEventListener.createProxyIfNecessary(LoadEvent, EntityPersister, EntityKey, LoadEventListener$LoadType, PersistenceContext) line: 298
      DefaultLoadEventListener.proxyOrLoad(LoadEvent, EntityPersister, EntityKey, LoadEventListener$LoadType) line: 219
      DefaultLoadEventListener.onLoad(LoadEvent, LoadEventListener$LoadType) line: 126
      SessionImpl.fireLoad(LoadEvent, LoadEventListener$LoadType) line: 905
      SessionImpl.internalLoad(String, Serializable, boolean, boolean) line: 873
      ManyToOneType(EntityType).resolveIdentifier(Serializable, SessionImplementor) line: 590
      ManyToOneType(EntityType).resolve(Object, SessionImplementor, Object) line: 412
      TwoPhaseLoad.initializeEntity(Object, boolean, SessionImplementor, PreLoadEvent, PostLoadEvent) line: 139
      EntityLoader(Loader).initializeEntitiesAndCollections(List, Object, SessionImplementor, boolean) line: 877
      EntityLoader(Loader).doQuery(SessionImplementor, QueryParameters, boolean) line: 752
      EntityLoader(Loader).doQueryAndInitializeNonLazyCollections(SessionImplementor, QueryParameters, boolean) line: 259
      EntityLoader(Loader).loadEntity(SessionImplementor, Object, Type, Object, String, Serializable, EntityPersister) line: 1881
      EntityLoader(AbstractEntityLoader).load(SessionImplementor, Object, Object, Serializable) line: 71
      EntityLoader(AbstractEntityLoader).load(Serializable, Object, SessionImplementor) line: 65
      SingleTableEntityPersister(AbstractEntityPersister).load(Serializable, Object, LockMode, SessionImplementor) line: 3072
      DefaultLoadEventListener.loadFromDatasource(LoadEvent, EntityPersister, EntityKey, LoadEventListener$LoadType) line: 434
      DefaultLoadEventListener.doLoad(LoadEvent, EntityPersister, EntityKey, LoadEventListener$LoadType) line: 415
      DefaultLoadEventListener.load(LoadEvent, EntityPersister, EntityKey, LoadEventListener$LoadType) line: 165
      DefaultLoadEventListener.proxyOrLoad(LoadEvent, EntityPersister, EntityKey, LoadEventListener$LoadType) line: 223
      DefaultLoadEventListener.onLoad(LoadEvent, LoadEventListener$LoadType) line: 126
      SessionImpl.fireLoad(LoadEvent, LoadEventListener$LoadType) line: 905
      SessionImpl.get(String, Serializable) line: 842
      SessionImpl.get(Class, Serializable) line: 835
      FullTextSessionImpl.get(Class, Serializable) line: 335
      HivemindFullTextSessionWrapper.get(Class, Serializable) line: 302
      $FullTextSession_11c689001bf.get(Class, Serializable) line: not available
      $FullTextSession_11c689001c0.get(Class, Serializable) line: not available
      BusinessServiceImpl.getById(Long, Class) line: 257
      $BusinessService_11c6890013b.getById(Long, Class) line: not available
      $BusinessService_11c6890013a.getById(Long, Class) line: not available
      EligibilityListenerImpl(AbstractMessageListener).receiveMessage(Reader) line: 134
      $EligibilityListener_11c68900134.receiveMessage(Reader) line: not available
      $EligibilityListener_11c68900133.receiveMessage(Reader) line: not available
      MessageListenerServlet.handlePost(HttpServletRequest, HttpServletResponse) line: 90
      MessageListenerServlet(AbstractHttpServlet).doPost(HttpServletRequest, HttpServletResponse) line: 99
      MessageListenerServlet(HttpServlet).service(HttpServletRequest, HttpServletResponse) line: 727
      MessageListenerServlet(HttpServlet).service(ServletRequest, ServletResponse) line: 820
      ServletHolder.handle(ServletRequest, ServletResponse) line: 487
      ServletHandler$CachedChain.doFilter(ServletRequest, ServletResponse) line: 1097
      HiveMindFilter(HiveMindFilter).doFilter(ServletRequest, ServletResponse, FilterChain) line: 172
      ServletHandler$CachedChain.doFilter(ServletRequest, ServletResponse) line: 1088
      ServletHandler.handle(String, HttpServletRequest, HttpServletResponse, int) line: 360
      SecurityHandler.handle(String, HttpServletRequest, HttpServletResponse, int) line: 216
      SessionHandler.handle(String, HttpServletRequest, HttpServletResponse, int) line: 181
      WebAppContext(ContextHandler).handle(String, HttpServletRequest, HttpServletResponse, int) line: 729
      WebAppContext.handle(String, HttpServletRequest, HttpServletResponse, int) line: 405
      Server(HandlerWrapper).handle(String, HttpServletRequest, HttpServletResponse, int) line: 152
      Server.handle(HttpConnection) line: 324
      HttpConnection.handleRequest() line: 505
      HttpConnection$RequestHandler.content(Buffer) line: 843
      HttpParser.parseNext() line: 647
      HttpParser.parseAvailable() line: 211
      HttpConnection.handle() line: 380
      SelectChannelConnector$ConnectorEndPoint(SelectChannelEndPoint).run() line: 395
      QueuedThreadPool$PoolThread.run() line: 488