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)

at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)

at org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:256)

at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)

at com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:167)

at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)

at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)

at com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:265)

at org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:76)

at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)

at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)

at com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:138)

at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)

at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:229)

at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)

at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)

at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:229)

at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)

at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)

at com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:191)

at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)

at org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:73)

at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)

at org.apache.struts2.interceptor.DateTextFieldInterceptor.intercept(DateTextFieldInterceptor.java:125)

at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)

at org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:91)

at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)

at org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:253)

at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)

at com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:100)

at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)

at com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:141)

at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)

at com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:145)

at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)

at com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:171)

at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)

at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)

at com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:139)

at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)

at org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)

at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)

at com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:193)

at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)

at com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:189)

at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)

at org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:54)

at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:564)

at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:81)

at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:99)

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:127)

at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)

at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)

at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)

at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:879)

at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:610)

at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1777)

at java.lang.Thread.run(Thread.java:745)