我正在尝试使用Hibernate和Spring来创建一个Web应用程序。在尝试创建登录表单时，我搜索一个帐户并尝试通过调用
在AccountDAOImpl中创建它
Account account = accountDAO.findAccount(username);
我在第一行收到错误：
return (Account)criteria.uniqueResult();
错误为org.hibernate.InstantiationException: No default constructor for entity
实体表具有指定的无参数构造函数
public Account(){}
还有另一个带参数的构造函数，但即使我将其注释掉，错误仍然会发生。
我完全迷失在这里，错误信息是明确的，但即使我做了应该解决的问题，它仍然会发生。有谁知道可能是什么原因？
整个痕迹：
org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter.doFilter An internal error occurred while trying to authenticate the user.
org.springframework.security.authentication.InternalAuthenticationServiceException: No default constructor for entity: : com.mycompany.entity.Account
at org.springframework.security.authentication.dao.DaoAuthenticationProvider.retrieveUser(DaoAuthenticationProvider.java:126)
at org.springframework.security.authentication.dao.AbstractUserDetailsAuthenticationProvider.authenticate(AbstractUserDetailsAuthenticationProvider.java:143)
at org.springframework.security.authentication.ProviderManager.authenticate(ProviderManager.java:167)
at org.springframework.security.authentication.ProviderManager.authenticate(ProviderManager.java:192)
at org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter.attemptAuthentication(UsernamePasswordAuthenticationFilter.java:93)
at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:217)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:120)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:64)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:91)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:53)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:213)
at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:176)
at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:346)
at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:262)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:478)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:80)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:624)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:341)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:783)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:798)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1441)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
Caused by: org.hibernate.InstantiationException: No default constructor for entity: : com.mycompany.entity.Account
at org.hibernate.tuple.PojoInstantiator.instantiate(PojoInstantiator.java:81)
at org.hibernate.tuple.PojoInstantiator.instantiate(PojoInstantiator.java:101)
at org.hibernate.tuple.entity.AbstractEntityTuplizer.instantiate(AbstractEntityTuplizer.java:635)
at org.hibernate.persister.entity.AbstractEntityPersister.instantiate(AbstractEntityPersister.java:4648)
at org.hibernate.internal.SessionImpl.instantiate(SessionImpl.java:1483)
at org.hibernate.internal.SessionImpl.instantiate(SessionImpl.java:1467)
at org.hibernate.loader.Loader.instanceNotYetLoaded(Loader.java:1645)
at org.hibernate.loader.Loader.getRow(Loader.java:1543)
at org.hibernate.loader.Loader.getRowFromResultSet(Loader.java:727)
at org.hibernate.loader.Loader.processResultSet(Loader.java:972)
at org.hibernate.loader.Loader.doQuery(Loader.java:930)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:336)
at org.hibernate.loader.Loader.doList(Loader.java:2610)
at org.hibernate.loader.Loader.doList(Loader.java:2593)
at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2422)
at org.hibernate.loader.Loader.list(Loader.java:2417)
at org.hibernate.loader.criteria.CriteriaLoader.list(CriteriaLoader.java:109)
at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1787)
at org.hibernate.internal.CriteriaImpl.list(CriteriaImpl.java:363)
at org.hibernate.internal.CriteriaImpl.uniqueResult(CriteriaImpl.java:385)
at com.mycompany.dao.impl.AccountDAOImpl.findAccount(AccountDAOImpl.java:24)
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:497)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:302)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99)
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:281)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:208)
at com.sun.proxy.$Proxy91.findAccount(Unknown Source)
at com.mycompany.authentication.MyDBAuthenticationService.loadUserByUsername(MyDBAuthenticationService.java:25)
at org.springframework.security.authentication.dao.DaoAuthenticationProvider.retrieveUser(DaoAuthenticationProvider.java:114)
... 39 more
答案 0 :(得分：1)
我离开了问题并离开了几个小时。当我回来再次尝试时，一切都按预期工作。我仍然不确定这里的核心问题是什么，但是我认为旧的'你试过把它关掉然后重新开启'有时甚至适用于编程。