tomcat+hibernate如何自动重连mysql

Question

我的程序部署在tomcat中，用的连接池是c3po。tomcat运行，mysql也正常运行的情况下，一切正常，我的程序读写数据库都ok。
为了做异常测试，我把msyql服务关闭掉，然后运行程序读写数据库，自然出了连接异常，可是我重新启动了mysql服务（tomcat没有重启，不允许重启），运行程序读写的时候，仍然是报连接错误，错误日志如下。我希望的情况是重启mysql后，程序能自动重连接的，不知道怎么配置了，附上我的hibernate配置（里面包括了c3p0连接池的配置），大家帮忙看看是不是哪配置错了。
** BEGIN NESTED EXCEPTION ** com.mysql.jdbc.CommunicationsException
MESSAGE: Communications link failure due to underlying exception: ** BEGIN NESTED EXCEPTION ** java.io.EOFException
MESSAGE: Can not read response from server. Expected to read 4 bytes, read 0 bytes before connection was unexpectedly lost.STACKTRACE: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:1997)
        at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2411)
        at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2916)
        at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1631)
        at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1723)
        at com.mysql.jdbc.Connection.execSQL(Connection.java:3256)
        at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1313)
        at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:1448)
        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.doList(Loader.java:2220)
        at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2104)
        at org.hibernate.loader.Loader.list(Loader.java:2099)
        at org.hibernate.loader.criteria.CriteriaLoader.list(CriteriaLoader.java:94)
        at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1569)
        at org.hibernate.impl.CriteriaImpl.list(CriteriaImpl.java:283)
        at org.hibernate.impl.CriteriaImpl.uniqueResult(CriteriaImpl.java:305)
        at com.alcatel.toneSynch.servlet.CreateAnnouncementServlet.existFile

Answer 1

(CreateAnnouncementServlet.java:229)
        at com.alcatel.toneSynch.servlet.CreateAnnouncementServlet.doPost(CreateAnnouncementServlet.java:100)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:710)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
        at com.alcatel.toneSynch.utils.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:21)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:215)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:210)
        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:870)
        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:685)
        at java.lang.Thread.run(Thread.java:595)
** END NESTED EXCEPTION **Last packet sent to the server was 2 ms ago.STACKTRACE:com.mysql.jdbc.CommunicationsException: Communications link failure due to underlying exception: ** BEGIN NESTED EXCEPTION ** 

Answer 2

java.io.EOFException
MESSAGE: Can not read response from server. Expected to read 4 bytes, read 0 bytes before connection was unexpectedly lost.STACKTRACE: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:1997)
        at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2411)
        at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2916)
        at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1631)
        at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1723)
        at com.mysql.jdbc.Connection.execSQL(Connection.java:3256)
        at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1313)
        at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:1448)
        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.doList(Loader.java:2220)
        at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2104)
        at org.hibernate.loader.Loader.list(Loader.java:2099)
        at org.hibernate.loader.criteria.CriteriaLoader.list(CriteriaLoader.java:94)
        at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1569)
        at org.hibernate.impl.CriteriaImpl.list(CriteriaImpl.java:283)
        at org.hibernate.impl.CriteriaImpl.uniqueResult(CriteriaImpl.java:305)
        at com.alcatel.toneSynch.servlet.CreateAnnouncementServlet.existFile(CreateAnnouncementServlet.java:229)
        at com.alcatel.toneSynch.servlet.CreateAnnouncementServlet.doPost(CreateAnnouncementServlet.java:100)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:710)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
        at com.alcatel.toneSynch.utils.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:21)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:215)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:210)
        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:870)
        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:685)
        at java.lang.Thread.run(Thread.java:595)
** END NESTED EXCEPTION **

Answer 3

Last packet sent to the server was 2 ms ago.
        at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2622)
        at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2916)
        at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1631)
        at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1723)
        at com.mysql.jdbc.Connection.execSQL(Connection.java:3256)
        at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1313)
        at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:1448)
        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.doList(Loader.java:2220)
        at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2104)
        at org.hibernate.loader.Loader.list(Loader.java:2099)
        at org.hibernate.loader.criteria.CriteriaLoader.list(CriteriaLoader.java:94)
        at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1569)
        at org.hibernate.impl.CriteriaImpl.list(CriteriaImpl.java:283)
        at org.hibernate.impl.CriteriaImpl.uniqueResult(CriteriaImpl.java:305)
        at com.alcatel.toneSynch.servlet.CreateAnnouncementServlet.existFile(CreateAnnouncementServlet.java:229)
        at com.alcatel.toneSynch.servlet.CreateAnnouncementServlet.doPost(CreateAnnouncementServlet.java:100)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:710)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
        at com.alcatel.toneSynch.utils.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:21)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:215)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:210)
        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:870)
        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:685)
        at java.lang.Thread.run(Thread.java:595)
** END NESTED EXCEPTION **
        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:888)
        at com.mysql.jdbc.Connection.checkClosed(Connection.java:1930)
        at com.mysql.jdbc.Connection.prepareStatement(Connection.java:4721)
        at com.mysql.jdbc.Connection.prepareStatement(Connection.java:4687)
        at org.hibernate.jdbc.AbstractBatcher.getPreparedStatement(AbstractBatcher.java:505)
        at org.hibernate.jdbc.AbstractBatcher.prepareStatement(AbstractBatcher.java:94)
        at org.hibernate.jdbc.AbstractBatcher.prepareStatement(AbstractBatcher.java:87)
        at org.hibernate.jdbc.AbstractBatcher.prepareBatchStatement(AbstractBatcher.java:222)
        at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2224)
        ... 29 more
-------------------------

Answer 4

我用C3P0也遇到了你的这个问题，我在C3P0遇到的你这个问题，我弄了很久，都没有解决。为什么会出现这个问题，原来是Mysql服务器默认的“wait_timeout”是8小时，也就是说一个connection空闲超过8个小时，Mysql将自动断开该connection。像这样子就只能重启tomcat才能再次连接上去。后来改用proxool，就解决这个问题。
建议楼主改用proxool，用了后会觉得还不错。

Answer 5

嗯，我一直用proxool，没出现这种问题。