spring jpa 无法删除对象Removing a detached instance

Question

本人使用spring + jpa（hibernate实现）+ tomcat开发个项目，并实现webservice远程调用，使用原生jpa，而不是JpaTemplate，在删除对象时出错，错误信息如下，希望高手给予解答！非常感激！程序代码
@PersistenceContext EntityManager em;
public void bankDel(int userid,Object obj) throws Exception{
            em.remove(obj);
        }尝试过网上有人说的改成em.remove(em.merge(obj)),但是不行，提示什么remove的是一个null！错误信息
严重: Removing a detached instance DAO.bank.BankAccountDAO#5
java.lang.IllegalArgumentException: Removing a detached instance DAO.bank.BankAccountDAO#5
        at org.hibernate.ejb.event.EJB3DeleteEventListener.performDetachedEntityDeletionCheck(EJB3DeleteEventListener.java:45)
        at org.hibernate.event.def.DefaultDeleteEventListener.onDelete(DefaultDeleteEventListener.java:86)
        at org.hibernate.event.def.DefaultDeleteEventListener.onDelete(DefaultDeleteEventListener.java:52)
        at org.hibernate.impl.SessionImpl.fireDelete(SessionImpl.java:766)
        at org.hibernate.impl.SessionImpl.delete(SessionImpl.java:744)
        at org.hibernate.ejb.AbstractEntityManagerImpl.remove(AbstractEntityManagerImpl.java:253)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:198)
        at $Proxy84.remove(Unknown Source)
        at service.bank.BankOperation.bankDel(BankOperation.java:45)
        at service.bank.BankOperation$$FastClassByCGLIB$$3c2a612.invoke(<generated>)
        at net.sf.cglib.proxy.MethodProxy.invoke(MethodProxy.java:149)
        at org.springframework.aop.framework.Cglib2AopProxy$CglibMethodInvocation.invokeJoinpoint(Cglib2AopProxy.java:700)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:149)
        at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:138)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
        at org.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedingJoinPoint.java:77)
        at interceptor.Interceptor.doBasicProfiling(Interceptor.java:43)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethodWithGivenArgs(AbstractAspectJAdvice.java:627)
        at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethod(AbstractAspectJAdvice.java:616)
        at org.springframework.aop.aspectj.AspectJAroundAdvice.invoke(AspectJAroundAdvice.java:64)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
        at org.springframework.aop.aspectj.AspectJAfterAdvice.invoke(AspectJAfterAdvice.java:42)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
        at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:106)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
        at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:89)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
        at org.springframework.aop.framework.Cglib2AopProxy$DynamicAdvisedInterceptor.intercept(Cglib2AopProxy.java:635)
        at service.bank.BankOperation$$EnhancerByCGLIB$$5b072988.bankDel(<generated>)
        at webservice.bank.BankWebService.accountDestroy(BankWebService.java:229)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at com.sun.xml.ws.api.server.InstanceResolver$1.invoke(InstanceResolver.java:246)
        at com.sun.xml.ws.server.InvokerTube$2.invoke(InvokerTube.java:146)
        at com.sun.xml.ws.server.sei.EndpointMethodHandler.invoke(EndpointMethodHandler.java:257)
        at com.sun.xml.ws.server.sei.SEIInvokerTube.processRequest(SEIInvokerTube.java:93)
        at com.sun.xml.ws.api.pipe.Fiber.__doRun(Fiber.java:598)
        at com.sun.xml.ws.api.pipe.Fiber._doRun(Fiber.java:557)
        at com.sun.xml.ws.api.pipe.Fiber.doRun(Fiber.java:542)
        at com.sun.xml.ws.api.pipe.Fiber.runSync(Fiber.java:439)
        at com.sun.xml.ws.server.WSEndpointImpl$2.process(WSEndpointImpl.java:243)
        at com.sun.xml.ws.transport.http.HttpAdapter$HttpToolkit.handle(HttpAdapter.java:444)
        at com.sun.xml.ws.transport.http.HttpAdapter.handle(HttpAdapter.java:244)
        at com.sun.xml.ws.transport.http.servlet.ServletAdapter.handle(ServletAdapter.java:135)
        at com.sun.xml.ws.transport.http.servlet.WSServletDelegate.doGet(WSServletDelegate.java:129)
        at com.sun.xml.ws.transport.http.servlet.WSServletDelegate.doPost(WSServletDelegate.java:160)
        at com.sun.xml.ws.transport.http.servlet.WSServlet.doPost(WSServlet.java:75)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        at org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:390)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286)
        at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:845)
        at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
        at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
        at java.lang.Thread.run(Thread.java:619)

Answer 1

em.remove(obj); 
obj对象是从数据库中取出的嘛？

Answer 2

调试Obj有值obj是从EntityManager取出的，传到了外面的函数，然后又调用这个类的函数来删除！

Answer 3

spring的事务都配好了吗？正常时不能出现这样的问题，要不就是你获得的那个obj对象，和删除obj对象方法，在不同的session控制范围之内要不不可能报 Removing a “detached” instance 这个异常

Answer 4

刚才没看清楚你使用了webserviceIllegalArgumentException ：
  if not an entity or if a detached entity obj已经不能被识别了，需要从数据库查一次。

Answer 5

em.remove(em.getReference(Class clazz, id));

Answer 6

用 JPA 查出来的对象传递到方法之外去的话，这个对象成为游离状态em.remove 应该是受脱管的对象不知道为什么你使用 merge 还是行。还是不行的话，你只能使用 JPQL 语句的 DELETE FROM 进行删除，反正 entity 中有 id 值的。

Answer 7

我把函数参数由Object换成具体的我自己定义的BankAccountDAO后，错误变成下面的了：Exception in thread "AWT-EventQueue-0" javax.xml.ws.soap.SOAPFaultException: service.bank.BankOperation.bankDel(ILjava/lang/Object;)V
        at com.sun.xml.internal.ws.fault.SOAP11Fault.getProtocolException(SOAP11Fault.java:178)
        at com.sun.xml.internal.ws.fault.SOAPFaultBuilder.createException(SOAPFaultBuilder.java:119)
        at com.sun.xml.internal.ws.client.sei.SyncMethodHandler.invoke(SyncMethodHandler.java:108)
        at com.sun.xml.internal.ws.client.sei.SyncMethodHandler.invoke(SyncMethodHandler.java:78)
        at com.sun.xml.internal.ws.client.sei.SEIStub.invoke(SEIStub.java:107)
        at $Proxy33.accountDestroy(Unknown Source)
        at bankgui.internalframe.BankJInternalFrame.jButton10ActionPerformed(BankJInternalFrame.java:2114)
        at bankgui.internalframe.BankJInternalFrame.access$1600(BankJInternalFrame.java:28)
        at bankgui.internalframe.BankJInternalFrame$19.actionPerformed(BankJInternalFrame.java:1254)
        at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995)
        at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2318)
        at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
        at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
        at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:236)
        at java.awt.Component.processMouseEvent(Component.java:6263)
        at javax.swing.JComponent.processMouseEvent(JComponent.java:3267)
        at java.awt.Component.processEvent(Component.java:6028)
        at java.awt.Container.processEvent(Container.java:2041)
        at java.awt.Component.dispatchEventImpl(Component.java:4630)
        at java.awt.Container.dispatchEventImpl(Container.java:2099)
        at java.awt.Component.dispatchEvent(Component.java:4460)
        at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4574)
        at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4238)
        at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4168)
        at java.awt.Container.dispatchEventImpl(Container.java:2085)
        at java.awt.Window.dispatchEventImpl(Window.java:2475)
        at java.awt.Component.dispatchEvent(Component.java:4460)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)
Caused by: java.lang.NoSuchMethodError: service.bank.BankOperation.bankDel(ILjava/lang/Object;)V
        at webservice.bank.BankWebService.accountDestroy(BankWebService.java:229)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at com.sun.xml.ws.api.server.InstanceResolver$1.invoke(InstanceResolver.java:246)
        at com.sun.xml.ws.server.InvokerTube$2.invoke(InvokerTube.java:146)
        at com.sun.xml.ws.server.sei.EndpointMethodHandler.invoke(EndpointMethodHandler.java:257)
        at com.sun.xml.ws.server.sei.SEIInvokerTube.processRequest(SEIInvokerTube.java:93)
        at com.sun.xml.ws.api.pipe.Fiber.__doRun(Fiber.java:598)
        at com.sun.xml.ws.api.pipe.Fiber._doRun(Fiber.java:557)
        at com.sun.xml.ws.api.pipe.Fiber.doRun(Fiber.java:542)
        at com.sun.xml.ws.api.pipe.Fiber.runSync(Fiber.java:439)
        at com.sun.xml.ws.server.WSEndpointImpl$2.process(WSEndpointImpl.java:243)
        at com.sun.xml.ws.transport.http.HttpAdapter$HttpToolkit.handle(HttpAdapter.java:444)
        at com.sun.xml.ws.transport.http.HttpAdapter.handle(HttpAdapter.java:244)
        at com.sun.xml.ws.transport.http.servlet.ServletAdapter.handle(ServletAdapter.java:135)
        at com.sun.xml.ws.transport.http.servlet.WSServletDelegate.doGet(WSServletDelegate.java:129)
        at com.sun.xml.ws.transport.http.servlet.WSServletDelegate.doPost(WSServletDelegate.java:160)
        at com.sun.xml.ws.transport.http.servlet.WSServlet.doPost(WSServlet.java:75)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        at org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:390)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286)
        at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:845)
        at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
        at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
        at java.lang.Thread.run(Thread.java:619)