问题描述
问题是这样我在做一个登录功能，用的是jap的EntityManager对象查询。查询语句：{Useruser=(User)em.createQuery("selectenfrom"+getEntityName(this.entityClass)+"asenwhereusName=:nameandusPsword=:pwd").setParameter("name",name).setParameter("pwd",pwd).getSingleResult();}问题出现了：当我输入正确用户名和密码时没有报错，但是我输入不正确用户名和密码时就会报出错误。就是想知道用EntityManager对象查询时，是不是当没有查询返回结果就会报错，该如何解决这个问题？错误信息：javax.persistence.NoResultException:Noentityfoundforqueryatorg.hibernate.ejb.QueryImpl.getSingleResult(QueryImpl.java:280)atcom.zuo.dao.impl.UserDaoImpl.userLogin(UserDaoImpl.java:40)atsun.reflect.NativeMethodAccessorImpl.invoke0(NativeMethod)atsun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)atsun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)atjava.lang.reflect.Method.invoke(Method.java:597)atorg.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:309)atorg.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:196)at$Proxy21.userLogin(UnknownSource)atcom.zuo.service.impl.UserServiceImpl.userLogin(UserServiceImpl.java:31)atsun.reflect.NativeMethodAccessorImpl.invoke0(NativeMethod)atsun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)atsun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)atjava.lang.reflect.Method.invoke(Method.java:597)atorg.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:309)atorg.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183)atorg.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)atorg.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:110)atorg.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)atorg.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:202)at$Proxy24.userLogin(UnknownSource)atcom.zuo.action.UserAction.login(UserAction.java:34)atsun.reflect.NativeMethodAccessorImpl.invoke0(NativeMethod)atsun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)atsun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)atjava.lang.reflect.Method.invoke(Method.java:597)atcom.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:446)atcom.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:285)atcom.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)atorg.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:256)atcom.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)atcom.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:176)atcom.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)atcom.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)atcom.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:265)atorg.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68)atcom.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)atcom.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)atcom.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:138)atcom.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)atcom.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:238)atcom.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)atcom.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)atcom.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:238)atcom.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)atcom.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)atcom.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:191)atcom.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)atorg.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:73)atcom.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)atorg.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:91)atcom.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)atorg.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:252)atcom.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)atcom.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:100)atcom.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)atcom.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:141)atcom.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)atcom.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:145)atcom.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)atcom.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:171)atcom.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)atcom.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)atcom.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:176)atcom.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)atorg.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)atcom.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)atcom.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:193)atcom.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)atcom.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:187)atcom.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)atorg.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:54)atorg.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:544)atorg.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)atorg.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:91)atorg.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)atorg.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)atorg.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)atorg.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)atorg.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)atorg.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)atorg.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)atorg.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286)atorg.apache.coyote.http11.Http11Processor.process(Http11Processor.java:845)atorg.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)atorg.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)atjava.lang.Thread.run(Thread.java:619)
解决方案
解决方案二：
写错了不是jap时jpa
解决方案三：
在getSingleResult的源码里有这样一句：@throwsEntityNotFoundExceptionifthereisnoresult所以,你得处理异常.
解决方案四：
还是写个sql语句吧,简单多了...