如果您对MySQLNonTransientConnectionException：连接关闭后不允许进行任何操作感兴趣，那么本文将是一篇不错的选择，我们将为您详在本文中，您将会了解到关于MySQLNon

如果您对MySQLNonTransientConnectionException：连接关闭后不允许进行任何操作感兴趣，那么本文将是一篇不错的选择，我们将为您详在本文中，您将会了解到关于MySQLNonTransientConnectionException：连接关闭后不允许进行任何操作的详细内容，我们还将为您解答mysql 关闭连接的相关问题，并且为您提供关于.jdbc4.MySQLNonTransientConnectionException: No operations allowed after connection closed.、.MySQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 5 times. Giving up.、Azure MySQL服务器-MySQLNonTransientConnectionException：数据包混乱、CannotCreateTransactionException: Could not open JDBC Connection GetConnectionTimeoutException的有价值信息。

本文目录一览：

• MySQLNonTransientConnectionException：连接关闭后不允许进行任何操作（mysql 关闭连接）
• .jdbc4.MySQLNonTransientConnectionException: No operations allowed after connection closed.
• .MySQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 5 times. Giving up.
• Azure MySQL服务器-MySQLNonTransientConnectionException：数据包混乱
• CannotCreateTransactionException: Could not open JDBC Connection GetConnectionTimeoutException

MySQLNonTransientConnectionException：连接关闭后不允许进行任何操作（mysql 关闭连接）

我构建了一个Web应用程序，并在本地完美部署。我将其部署在远程服务器上并开始获取：except

> 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)>root cause>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)>root cause>com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: No operations allowed after connection closed.Connection was implicitly closed due to underlying exception/error:** BEGIN NESTED EXCEPTION **     >com.mysql.jdbc.exceptions.jdbc4.CommunicationsException MESSAGE: Communications link failure>Last packet sent to the server was 43 ms ago.>STACKTRACE:>com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure>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 **>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)

我已经使用hibernate和struts来构建Web应用程序并将该Web应用程序部署在Linux服务器中。它的登录功能在一段时间内运行良好，但是登录后无法正常工作，并且在Tomcat日志文件中显示了Exception。

答案1

小编典典

根据错误堆栈跟踪，将丢失与MySQL服务器的连接。

>root cause>com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException:  No operations allowed after connection closed.  Connection was implicitly closed due to underlying exception/error:** BEGIN NESTED EXCEPTION **     >com.mysql.jdbc.exceptions.jdbc4.CommunicationsException MESSAGE: Communications link failure>Last packet sent to the server was 43 ms ago.>STACKTRACE:>com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

很清楚，根本原因是Communications link failure。

尝试ping您的数据库服务器，看看是否能够连接。 否则解决网络问题，然后连接。没有其他选择。

您可以减轻ping数据库服务器的负担，以检查连接可用性。

.jdbc4.MySQLNonTransientConnectionException: No operations allowed after connection closed.

com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: No operations allowed after connection closed.
    at sun.reflect.GeneratedConstructorAccessor65.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
    at com.mysql.jdbc.Util.getInstance(Util.java:386)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1015)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:989)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:975)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:920)
    at com.mysql.jdbc.ConnectionImpl.throwConnectionClosedException(ConnectionImpl.java:1311)
    at com.mysql.jdbc.ConnectionImpl.checkClosed(ConnectionImpl.java:1303)
    at com.mysql.jdbc.ConnectionImpl.createStatement(ConnectionImpl.java:2683)
    at com.mysql.jdbc.ConnectionImpl.createStatement(ConnectionImpl.java:2665)
    at security.view.util.SqlUtils.insert(SqlUtils.java:315)
    at security.view.util.SqlUtils.processKill(SqlUtils.java:109)
    at security.view.util.SqlUtils.sql(SqlUtils.java:148)
    at security.view.util.SqlUtils.sqlJsonObj(SqlUtils.java:418)
    at security.view.util.SqlUtils.processKill(SqlUtils.java:97)
    at security.view.util.SqlUtils.sql(SqlUtils.java:148)
 

.MySQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 5 times. Giving up.

com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 5 times. Giving up.
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:408)
	at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
	at com.mysql.jdbc.Util.getInstance(Util.java:386)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1015)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:989)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:975)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:920)
	at com.mysql.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:2385)
	at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2306)
	at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:834)
	at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
	at sun.reflect.GeneratedConstructorAccessor4.newInstance(Unknown Source)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:408)
	at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
	at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:416)
	at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:346)
	at com.mysql.jdbc.jdbc2.optional.MysqlDataSource.getConnection(MysqlDataSource.java:443)
	at com.mysql.jdbc.jdbc2.optional.MysqlDataSource.getConnection(MysqlDataSource.java:141)
	at com.mysql.jdbc.jdbc2.optional.MysqlDataSource.getConnection(MysqlDataSource.java:111)
	at cn.qjj.mysql.MySQLPool.getNewConnection(MySQLPool.java:72)
	at cn.qjj.mysql.MySQLPool.init(MySQLPool.java:63)
	at cn.qjj.mysql.MySQLPool.<init>(MySQLPool.java:32)
	at cn.qjj.mysql.MySQLPool.getInstance(MySQLPool.java:39)
	at cn.qjj.mysql.SqlUtils.<clinit>(SqlUtils.java:33)
	at cn.qjj.solr.MsgUtil.main(MsgUtil.java:31)
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Data source rejected establishment of connection,  message from server: "Too many connections"
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:408)
	at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
	at com.mysql.jdbc.Util.getInstance(Util.java:386)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1015)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:989)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:975)
	at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1112)
	at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2483)
	at com.mysql.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:2324)
	... 18 more
java.lang.NullPointerException
	at java.util.concurrent.ConcurrentHashMap.putVal(ConcurrentHashMap.java:1011)
	at java.util.concurrent.ConcurrentHashMap.put(ConcurrentHashMap.java:1006)
	at cn.qjj.mysql.MySQLPool.init(MySQLPool.java:63)
	at cn.qjj.mysql.MySQLPool.<init>(MySQLPool.java:32)
	at cn.qjj.mysql.MySQLPool.getInstance(MySQLPool.java:39)
	at cn.qjj.mysql.SqlUtils.<clinit>(SqlUtils.java:33)
	at cn.qjj.solr.MsgUtil.main(MsgUtil.java:31)

Azure MySQL服务器-MySQLNonTransientConnectionException：数据包混乱

我不知道您的问题是否已经解决。

我在将 Java 应用程序连接到 Azure MySQL 服务器时遇到了同样的问题。应用程序连接到本地 MySQL 服务器，但未连接到 Azure MySQL。在我的例子中，本地 MySQL 版本是 5.6，但 Azure MySQL 版本设置为 8.0。我认为这就是问题的原因。

我为我的应用程序配置了“mysql-connector-java-5.0.8.jar”，它抛出“MySQLNonTransientConnectionException：数据包乱序”错误。

我将 jar 更新为“mysql-connector-java-8.0.25.jar”并解决了问题。请检查您的 Azure MySQL 版本并尝试上述解决方案，看看是否能解决问题。

CannotCreateTransactionException: Could not open JDBC Connection GetConnectionTimeoutException

最近在 开发环境的 1核 2G内存的 云服务器上面 出现了 错误 **GetConnectionTimeoutException **

CannotCreateTransactionException: Could not open JDBC Connection for transaction; nested exception is com.alibaba.druid.pool.GetConnectionTimeoutException: wait millis 30001,
...

刚开始的时候没有这个问题，有时候运行使用的时候 偶尔会出现，但是过了一段时间，这个问题 又会 自动修复，。。。

有点奇怪。使用的 数据源是 druid

  初始化大小，最小，最大
    initialSize: 5
    minIdle: 1
    maxActive: 10

以上就是 开始的配置，因为数据库是 另一个云服务器，如果偶尔出现就是 网络的问题。可是本地 运行代码和 Navicat 连接云数据库都没有问题
。。。而且问题经常出现影响到 开发使用。

解决

参考博客

将连接超时时间 设置大一些？

默认连接是设置超时 60S 的，我觉得没必要再设置大了。而且本地连接 远程 的数据库都是 没有问题，连接都是很快的。
不是 连接时间的问题

会不会是 连接数设置太大了？

改为：

 initialSize: 1
    minIdle: 1
    maxActive: 3

结果还是出现了 。。。同样的问题，而且一开机 项目启动访问就出现了，问题更严重了
查询数据库 连接线程情况：

SELECT *
FROM information_schema.processlist    
WHERE  `user`=''root'' and `HOST` like ''%175.24.232.217%'';

结果发现了 3个连接 都是 Sleep 状态。。。出现了 连接泄露

为什么连接都 sleep ?

估计是 本来连接获取数据库资源就慢，然后浏览器又断开连接了。
或者很多web 请求要请求资料。但是 这些请求又迟迟获取不到数据库连接，因此出现了连接获取超时。
而且因为我这个是 单核服务器，处理本来就慢，不能并发处理。同时 IO耗时最多。因此我分析加多 最大连接数即可

设置 最大连接数为 20

 initialSize: 5
    minIdle: 1
    maxActive: 20

问题解决.

反思为什么 单核服务器要加大最大连接数，而且 多核服务器不用

之前项目放在公司内网多核服务器里面，并没有出现这个问题。
而且我也看过一些资料，连接数不少越大越好的。而且 默认 官方的最大连接数就是 10
参考 设置数据库连接池
即 单机的确实要加多 一些连接数的，而多核的反而减低连接数能够达到更大的性能
几年前一个项目，服务器2核的，设置了100连接数，开始没问题，运行不久就DAO处理非常慢，这就是连接数太多了，加大了上下文切换

关于MySQLNonTransientConnectionException：连接关闭后不允许进行任何操作和mysql 关闭连接的介绍现已完结，谢谢您的耐心阅读，如果想了解更多关于.jdbc4.MySQLNonTransientConnectionException: No operations allowed after connection closed.、.MySQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 5 times. Giving up.、Azure MySQL服务器-MySQLNonTransientConnectionException：数据包混乱、CannotCreateTransactionException: Could not open JDBC Connection GetConnectionTimeoutException的相关知识，请在本站寻找。

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• ConnectionException
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