title: MySQLNonTransientConnectionException: No operations allowed after connection closed.Connection
body: <p>I built an web application and deployed locally working perfect.  I deployed it on a remote server and started getting the :
  exception </p>
  
  <pre><code>&gt; javax.servlet.ServletException: could not execute query 
  org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:518) 
  org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:421) 
  
  
  &gt;root cause 
  
  &gt;org.hibernate.exception.JDBCConnectionException: could not execute query 
  org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:74) 
  org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43) 
  org.hibernate.loader.Loader.doList(Loader.java:2223) 
  org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2104) 
  org.hibernate.loader.Loader.list(Loader.java:2099) 
  org.hibernate.loader.criteria.CriteriaLoader.list(CriteriaLoader.java:94) 
  org.hibernate.impl.SessionImpl.list(SessionImpl.java:1569) 
  org.hibernate.impl.CriteriaImpl.list(CriteriaImpl.java:283) 
  data.dao.UserDAO.findByUsername(UserDAO.java:42) 
  action.registration.LoginAction.execute(LoginAction.java:24) 
  sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
  sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) 
  sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) 
  java.lang.reflect.Method.invoke(Method.java:597) 
  com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:399) 
  com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:262) 
  com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:224) 
  com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:213) 
  com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:86) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:150) 
  org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:48) 
  com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:86) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:123) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  com.opensymphony.xwork2.interceptor.ParametersInterceptor.intercept(ParametersInterceptor.java:161) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:105) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:83) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:207) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:74) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:127) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  org.apache.struts2.interceptor.ProfilingActivationInterceptor.intercept(ProfilingActivationInterceptor.java:107) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:206) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:115) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:143) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  com.opensymphony.xwork2.interceptor.PrepareInterceptor.intercept(PrepareInterceptor.java:115) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:170) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:123) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:176) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:50) 
  org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:507) 
  org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:421) 
  
  &gt;root cause 
  
  &gt;com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: No operations allowed after connection closed.Connection was implicitly closed due to underlying exception/error: 
  
  
  ** BEGIN NESTED EXCEPTION ** 
      &gt;com.mysql.jdbc.exceptions.jdbc4.CommunicationsException 
  MESSAGE: Communications link failure 
  
  &gt;Last packet sent to the server was 43 ms ago. 
  
  &gt;STACKTRACE: 
  
  &gt;com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure 
  
  &gt;Last packet sent to the server was 43 ms ago. 
  at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) 
  at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39) 
  at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27) 
  at java.lang.reflect.Constructor.newInstance(Constructor.java:513) 
  at com.mysql.jdbc.Util.handleNewInstance(Util.java:406) 
  at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1074) 
  at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2985) 
  at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2871) 
  at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3414) 
  at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1936) 
  at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2060) 
  at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2542) 
  at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1734) 
  at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:1885) 
  at org.hibernate.jdbc.AbstractBatcher.getResultSet(AbstractBatcher.java:186) 
  at org.hibernate.loader.Loader.getResultSet(Loader.java:1787) 
  at org.hibernate.loader.Loader.doQuery(Loader.java:674) 
  at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:236) 
  at org.hibernate.loader.Loader.loadEntity(Loader.java:1860) 
  at org.hibernate.loader.entity.AbstractEntityLoader.load(AbstractEntityLoader.java:48) 
  at org.hibernate.loader.entity.AbstractEntityLoader.load(AbstractEntityLoader.java:42) 
  at org.hibernate.persister.entity.AbstractEntityPersister.load(AbstractEntityPersister.java:3042) 
  at org.hibernate.event.def.DefaultLoadEventListener.loadFromDatasource(DefaultLoadEventListener.java:395) 
  at org.hibernate.event.def.DefaultLoadEventListener.doLoad(DefaultLoadEventListener.java:375) 
  at org.hibernate.event.def.DefaultLoadEventListener.load(DefaultLoadEventListener.java:139) 
  at org.hibernate.event.def.DefaultLoadEventListener.proxyOrLoad(DefaultLoadEventListener.java:195) 
  at org.hibernate.event.def.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:103) 
  at org.hibernate.impl.SessionImpl.fireLoad(SessionImpl.java:878) 
  at org.hibernate.impl.SessionImpl.get(SessionImpl.java:815) 
  at org.hibernate.impl.SessionImpl.get(SessionImpl.java:808) 
  at data.base._BaseRootDAO.get(_BaseRootDAO.java:228) 
  at data.base._BaseRootDAO.get(_BaseRootDAO.java:217) 
  at data.base.BaseUserDAO.get(BaseUserDAO.java:49) 
  at util.UserUtil.getUser(UserUtil.java:22) 
  at action.market.ArmsDealerAction.display(ArmsDealerAction.java:62) 
  at action.market.ArmsDealerAction.displayUser(ArmsDealerAction.java:54) 
  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.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:399) 
  at com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:262) 
  at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:224) 
  at com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:213) 
  at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:86) 
  at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  at com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  at com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:150) 
  at org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:48) 
  at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:86) 
  at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  at com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  at com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:123) 
  at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  at com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  at com.opensymphony.xwork2.interceptor.ParametersInterceptor.intercept(ParametersInterceptor.java:161) 
  at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  at com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  at com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:105) 
  at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  at com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  at org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:83) 
  at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  at com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  at org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:207) 
  at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  at com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  at com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:74) 
  at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  at com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  at com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:127) 
  at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  at com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  at org.apache.struts2.interceptor.ProfilingActivationInterceptor.intercept(ProfilingActivationInterceptor.java:107) 
  at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  at 
  at com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  at com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:123) 
  at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  at com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  at com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:176) 
  at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188) 
  at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213) 
  at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:174) 
  at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127) 
  at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117) 
  at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:108) 
  at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:151) 
  at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:874) 
  at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:665) 
  at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:528) 
  at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:81) 
  at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:689) 
  at java.lang.Thread.run(Thread.java:619) 
  Caused by: java.io.EOFException: Can not read response from server. Expected to read 4 bytes, read 0 bytes before connection was unexpectedly lost. 
  at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:2431) 
  at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2882) 
  ... 141 more 
  
  
  ** END NESTED EXCEPTION ** 
  
  
  &gt;sun.reflect.GeneratedConstructorAccessor72.newInstance(Unknown Source) 
  sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27) 
  java.lang.reflect.Constructor.newInstance(Constructor.java:513) 
  com.mysql.jdbc.Util.handleNewInstance(Util.java:406) 
  com.mysql.jdbc.Util.getInstance(Util.java:381) 
  com.mysql.jdbc.SQLError.createSQLException(SQLError.java:984) 
  com.mysql.jdbc.SQLError.createSQLException(SQLError.java:956) 
  com.mysql.jdbc.SQLError.createSQLException(SQLError.java:926) 
  com.mysql.jdbc.ConnectionImpl.checkClosed(ConnectionImpl.java:1098) 
  com.mysql.jdbc.ConnectionImpl.prepareStatement(ConnectionImpl.java:4076) 
  com.mysql.jdbc.ConnectionImpl.prepareStatement(ConnectionImpl.java:4042) 
  org.hibernate.jdbc.AbstractBatcher.getPreparedStatement(AbstractBatcher.java:505) 
  org.hibernate.jdbc.AbstractBatcher.getPreparedStatement(AbstractBatcher.java:423) 
  org.hibernate.jdbc.AbstractBatcher.prepareQueryStatement(AbstractBatcher.java:139) 
  org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1547) 
  org.hibernate.loader.Loader.doQuery(Loader.java:673) 
  org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:236) 
  org.hibernate.loader.Loader.doList(Loader.java:2220) 
  org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2104) 
  org.hibernate.loader.Loader.list(Loader.java:2099) 
  org.hibernate.loader.criteria.CriteriaLoader.list(CriteriaLoader.java:94) 
  org.hibernate.impl.SessionImpl.list(SessionImpl.java:1569) 
  org.hibernate.impl.CriteriaImpl.list(CriteriaImpl.java:283) 
  data.dao.UserDAO.findByUsername(UserDAO.java:42) 
  action.registration.LoginAction.execute(LoginAction.java:24) 
  sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
  sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) 
  sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) 
  java.lang.reflect.Method.invoke(Method.java:597) 
  com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:399) 
  com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:262) 
  com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:224) 
  com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:213) 
  com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:86) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:150) 
  org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:48) 
  com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:86) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:123) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  com.opensymphony.xwork2.interceptor.ParametersInterceptor.intercept(ParametersInterceptor.java:161) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:105) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:83) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:207) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:74) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219) 
  com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218) 
  com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455) 
  com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216) 
  com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:127) 
  </code></pre>
  
  <p>I have used hibernate and struts to build web application and deploy the web application in Linux server.Its login functionality working well for some time, But after that login not working and showing above Exception in Tomcat Log File.</p>