出现异常了

源自：5-4 添加事务管理-Spring整合Hibernate

出现异常了

ERROR org.apache.struts2.dispatcher.DefaultDispatcherErrorHandler:42 - Exception occurred during processing request: attempt to create saveOrUpdate event with null entity

java.lang.IllegalArgumentException: attempt to create saveOrUpdate event with null entity

at org.hibernate.event.SaveOrUpdateEvent.<init>(SaveOrUpdateEvent.java:63)

at org.hibernate.event.SaveOrUpdateEvent.<init>(SaveOrUpdateEvent.java:46)

at org.hibernate.impl.SessionImpl.save(SessionImpl.java:551)

at org.hibernate.impl.SessionImpl.save(SessionImpl.java:547)

at org.springframework.orm.hibernate3.HibernateTemplate$12.doInHibernate(HibernateTemplate.java:722)

at org.springframework.orm.hibernate3.HibernateTemplate$12.doInHibernate(HibernateTemplate.java:718)

at org.springframework.orm.hibernate3.HibernateTemplate.doExecute(HibernateTemplate.java:411)

at org.springframework.orm.hibernate3.HibernateTemplate.executeWithNativeSession(HibernateTemplate.java:379)

at org.springframework.orm.hibernate3.HibernateTemplate.save(HibernateTemplate.java:718)

at cn.muke.ssh.dao.ProductDao.save(ProductDao.java:15)

at cn.muke.ssh.service.ProductService.save(ProductService.java:24)

at cn.muke.ssh.service.ProductService$$FastClassByCGLIB$$6511f0ce.invoke(<generated>)

at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)

at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:698)

at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)

at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:110)

at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)

at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:631)

at cn.muke.ssh.service.ProductService$$EnhancerByCGLIB$$2edd71e9.save(<generated>)

at cn.muke.ssh.action.ProductAction.save(ProductAction.java:27)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

at java.lang.reflect.Method.invoke(Method.java:483)

at ognl.OgnlRuntime.invokeMethod(OgnlRuntime.java:870)

at ognl.OgnlRuntime.callAppropriateMethod(OgnlRuntime.java:1293)

at ognl.ObjectMethodAccessor.callMethod(ObjectMethodAccessor.java:68)

at com.opensymphony.xwork2.ognl.accessor.XWorkMethodAccessor.callMethodWithDebugInfo(XWorkMethodAccessor.java:117)

at com.opensymphony.xwork2.ognl.accessor.XWorkMethodAccessor.callMethod(XWorkMethodAccessor.java:108)

at ognl.OgnlRuntime.callMethod(OgnlRuntime.java:1369)

at ognl.ASTMethod.getValueBody(ASTMethod.java:90)

at ognl.SimpleNode.evaluateGetValueBody(SimpleNode.java:212)

at ognl.SimpleNode.getValue(SimpleNode.java:258)

at ognl.Ognl.getValue(Ognl.java:494)

at ognl.Ognl.getValue(Ognl.java:458)

at com.opensymphony.xwork2.ognl.OgnlUtil$2.execute(OgnlUtil.java:309)

at com.opensymphony.xwork2.ognl.OgnlUtil.compileAndExecute(OgnlUtil.java:340)

at com.opensymphony.xwork2.ognl.OgnlUtil.getValue(OgnlUtil.java:307)

at com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:423)

at com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:287)

at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:250)

at org.apache.struts2.interceptor.DeprecationInterceptor.intercept(DeprecationInterceptor.java:41)