com.microsoft.sqlserver.jdbc.SQLServerException: 该连接已关闭。 at com.microsoft.sqlserver.jdbc.SQLServerException.makeFromDriverError(SQLServerException.java:130) at com.microsoft.sqlserver.jdbc.SQLServerConnection.checkClosed(SQLServerConnection.java:294) at com.microsoft.sqlserver.jdbc.SQLServerConnection.prepareStatement(SQLServerConnection.java:1980) at com.microsoft.sqlserver.jdbc.SQLServerConnection.prepareStatement(SQLServerConnection.java:1702) at org.hibernate.jdbc.AbstractBatcher.getPreparedStatement(AbstractBatcher.java:497) at org.hibernate.jdbc.AbstractBatcher.getPreparedStatement(AbstractBatcher.java:415) at org.hibernate.jdbc.AbstractBatcher.prepareQueryStatement(AbstractBatcher.java:139) at org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1538) at org.hibernate.loader.Loader.doQuery(Loader.java:661) at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:224) at org.hibernate.loader.Loader.doList(Loader.java:2211) at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2095) at org.hibernate.loader.Loader.list(Loader.java:2090) at org.hibernate.loader.custom.CustomLoader.list(CustomLoader.java:289) at org.hibernate.impl.SessionImpl.listCustomQuery(SessionImpl.java:1695) at org.hibernate.impl.AbstractSessionImpl.list(AbstractSessionImpl.java:142) at org.hibernate.impl.SQLQueryImpl.list(SQLQueryImpl.java:150) at com.standsoft.service.PeisPatientService.GetPatientExamDepart(PeisPatientService.java:484) at com.standsoft.btree.Depart.exesql(Depart.java:26) at com.standsoft.controller.MainController.target(MainController.java:137) at sun.reflect.GeneratedMethodAccessor57.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:601) at org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:215) at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132) at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:749) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:689) at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:83) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:938) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:870) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961) at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:852) at javax.servlet.http.HttpServlet.service(HttpServlet.java:624) at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837) at javax.servlet.http.HttpServlet.service(HttpServlet.java:731) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103) at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:436) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1078) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:625) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1757) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1716) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:722)
问题原因：
该异常说明程序与数据库连接断开
为了排查问题，我们做如下几个假设
1，程序bug
2，部署程序的服务器（网络或其它）问题
3，部署数据库服务器（网络或其它）问题
问题探讨
a分析程序，并无明显bug
b模拟部署服务器故障，断开网络，出现上述异常。断开本地数据库服务，出现上述异常
c模拟部署数据库的服务器故障，断开数据库服务，出现上述异常。
在经过b和c故障后，a仍不能获取连接。分析发现，session和sessionfactory不为空，因此也没走到rebuildSessionFactory重连数据库。获取session代码如下
/** * Returns the ThreadLocal Session instance. Lazy initialize the * <code>SessionFactory</code> if needed. * * @return Session * @throws HibernateException */ public static Session getSession() throws HibernateException { Session session = threadLocal.get(); if (session == null || !session.isOpen()) { if (sessionFactory == null) { rebuildSessionFactory(); } session = (sessionFactory != null) ? sessionFactory.openSession() : null; threadLocal.set(session); } return session; } /** * Rebuild hibernate session factory * */ public static void rebuildSessionFactory() { System.out.println("-------------------------------rebuildSessionFactory----------------------------------"); try { configuration.configure(configFile); sessionFactory = configuration.buildSessionFactory(); } catch (Exception e) { System.err.println("%%%% Error Creating SessionFactory %%%%"); e.printStackTrace(); } }
既然数据库连接问题，给hibernate加上了连接池
hibernate配置文件部分代码如下
<session-factory>
<property name="dialect">com.standsoft.dialect.DialectForInkfish</property>
<property name="connection.url">jdbc:sqlserver://localhost:1433;DatabaseName=yanan</property>
<property name="connection.username">sa</property>
<property name="connection.password">yanan</property>
<property name="connection.driver_class">com.microsoft.sqlserver.jdbc.SQLServerDriver</property>
<property name="myeclipse.connection.profile">sql2008-4</property>
<property name="show_sql">true</property>
<property name="format_sql">true</property>
<property name="hibernate.connection.provider_class">org.hibernate.connection.C3P0ConnectionProvider</property>
<property name="hibernate.c3p0.min_size">1</property>
<property name="hibernate.c3p0.max_size">200</property>
<!-- Seconds a Connection can remain pooled but unused before being discarded. Zero means idle connections never expire. [See "Basic Pool Configuration"] -->
<property name="hibernate.c3p0.time_out">5</property>
<!-- The size of c3p0's global PreparedStatement cache. -->
<property name="hibernate.c3p0.max_statements">200</property>
</session-factory>
至此，在模拟bc故障并恢复后程序也恢复了正常。
网上看到有说hibernate用不用连接池没多大区别的。你们不知道别误人子弟哈。还有说connection不能静态的，若读者按照我的方法不行，可试试这个
网上还要配置c3p0错误的，大家注意。我的是按照官网配置的
附：相关jar包下载。csdn等网站下载要注册还要积分，我这里免费分享给大家，好用就给个赞吧