Tomcat-MySQL-Hibernate-c3p0超时/管道断裂

我一直在努力使我的web应用程序停止抛出断管/超时异常。我读过很多文章（，，和其他）和，但都没有用

我的

WEB-INF/lib

文件夹中有

c3p0-0.9.1.2.jar、hibernate-c3p0-4.1.1.Final.jar、hibernate-core-4.1.1.Final.jar和所有必需的jar文件。我不认为版本有问题，但我想，我应该列出细节
ApacheTomcat/6.0.24
，
MySQL版本14.14发行版5.1.70
。所有这些都是在Ubuntu 10.04.4 LTS上运行的，
lucid

在8小时（db）不活动后，我的catalina日志中出现以下异常：

10:18:45,657 WARN SqlExceptionHelper:143 - SQL Error: 0, SQLState: 08S01
10:18:45,660 ERROR SqlExceptionHelper:144 - The last packet successfully received from the server was 69,956,254 milliseconds ago. The last packet sent successfully to the server was 69,956,255 milliseconds ago. is longer than the server configured value of 'wait_timeout'. You should consider either expiring and/or testing connection validity before use in your application, increasing the server configured values for client timeouts, or using the Connector/J connection property 'autoReconnect=true' to avoid this problem.
org.hibernate.exception.JDBCConnectionException: The last packet successfully received from the server was 69,956,254 milliseconds ago. The last packet sent successfully to the server was 69,956,255 milliseconds ago. is longer than the server configured value of 'wait_timeout'. You should consider either expiring and/or testing connection validity before use in your application, increasing the server configured values for client timeouts, or using the Connector/J connection property 'autoReconnect=true' to avoid this problem.
at org.hibernate.exception.internal.SQLStateConversionDelegate.convert(SQLStateConversionDelegate.java:131)
at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:49)
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:125)
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:110)
at org.hibernate.engine.jdbc.internal.proxy.AbstractStatementProxyHandler.continueInvocation(AbstractStatementProxyHandler.java:129)
at org.hibernate.engine.jdbc.internal.proxy.AbstractProxyHandler.invoke(AbstractProxyHandler.java:81)
at sun.proxy.$Proxy24.executeQuery(Unknown Source)
at org.hibernate.loader.Loader.getResultSet(Loader.java:1962)
at org.hibernate.loader.Loader.doQuery(Loader.java:829)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:289)
at org.hibernate.loader.Loader.doList(Loader.java:2447)
at org.hibernate.loader.Loader.doList(Loader.java:2433)
at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2263)
at org.hibernate.loader.Loader.list(Loader.java:2258)
at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:470)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:355)
at org.hibernate.engine.query.spi.HQLQueryPlan.performList(HQLQueryPlan.java:196)
at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1161)
at org.hibernate.internal.QueryImpl.list(QueryImpl.java:101)
at gr.adds.myapp.server.db.DB.getBFromUser(DB.java:49)
at gr.adds.myapp.server.BSImpl.getBusesInfo(BSImpl.java:57)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:569)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(RemoteServiceServlet.java:208)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(RemoteServiceServlet.java:248)
at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(AbstractRemoteServiceServlet.java:62)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.jk.server.JkCoyoteHandler.invoke(JkCoyoteHandler.java:190)
at org.apache.jk.common.HandlerRequest.invoke(HandlerRequest.java:291)
at org.apache.jk.common.ChannelSocket.invoke(ChannelSocket.java:769)
at org.apache.jk.common.ChannelSocket.processConnection(ChannelSocket.java:698)
at org.apache.jk.common.ChannelSocket$SocketConnection.runIt(ChannelSocket.java:891)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:690)
at java.lang.Thread.run(Thread.java:679)
Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: The last packet successfully received from the server was 69,956,254 milliseconds ago. The last packet sent successfully to the server was 69,956,255 milliseconds ago. is longer than the server configured value of 'wait_timeout'. You should consider either expiring and/or testing connection validity before use in your application, increasing the server configured values for client timeouts, or using the Connector/J connection property 'autoReconnect=true' to avoid this problem.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:532)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1116)
at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:3364)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1983)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2163)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2624)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2127)
at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:2293)
at com.mchange.v2.c3p0.impl.NewProxyPreparedStatement.executeQuery(NewProxyPreparedStatement.java:76)
at sun.reflect.GeneratedMethodAccessor37.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at org.hibernate.engine.jdbc.internal.proxy.AbstractStatementProxyHandler.continueInvocation(AbstractStatementProxyHandler.java:122)
... 41 more
Caused by: java.net.SocketException: Broken pipe
at java.net.SocketOutputStream.socketWrite0(Native Method)
at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:109)
at java.net.SocketOutputStream.write(SocketOutputStream.java:153)
at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:82)
at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:140)
at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:3345)
... 51 more

这是我的
hibernate.cfg.xml
：

<session-factory>
    <!-- Database connection settings -->
    <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
    <property name="connection.url">jdbc:mysql://localhost:3306/mydb?autoReconnect=true</property>
    <property name="connection.username">dbuser</property>
    <property name="connection.password">dbpass</property>
    <!-- SQL dialect -->
    <property name="dialect">org.hibernate.dialect.MySQLDialect</property>
    <!-- Enable Hibernate's automatic session context management -->
    <property name="current_session_context_class">thread</property>
    <!-- Disable the second-level cache -->
    <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>
    <!-- Echo all executed SQL to stdout -->
    <property name="show_sql">false</property>
    <!-- Drop and re-create the database schema on startup -->
    <property name="hibernate.hbm2ddl.auto">update</property>
    <property name="hibernate.connection.useUnicode">true</property>
    <property name="hibernate.connection.characterEncoding">UTF-8</property>
    <!-- hibernate.cfg.xml -->

    <property name="connection.autoReconnect">true</property>
    <property name="connection.autoReconnectForPools">true</property>
    <property name="connection.is-connection-validation-required">true</property>
    <property name="current_session_context_class">thread</property>
    <!-- <property name="max_fetch_depth">1</property> -->

    <property name="hibernate.connection.provider_class">org.hibernate.service.jdbc.connections.internal.C3P0ConnectionProvider</property>
<!--        <property name="hibernate.c3p0.initial_size">5</property>  -->
<!--        <property name="hibernate.c3p0.min_size">5</property> -->
<!--        <property name="hibernate.c3p0.max_size">50</property> -->
<!--        <property name="hibernate.c3p0.timeout">1800</property> -->
<!--        <property name="hibernate.c3p0.max_statements">250</property> -->

<!--        <property name="hibernate.c3p0.idle_test_period">60</property> -->
<!--        <property name="hibernate.c3p0.acquire_increment">5</property> -->
    <property name="hibernate.c3p0.numHelperThreads">3</property>
    <!-- no "connection.pool_size" entry! -->    
    <!-- JDBC connection pool (use the built-in) -->
    <!-- <property name="connection.pool_size">1</property> -->  
<!--        <property name="hibernate.transaction.auto_close_session">false</property> -->
    <property name="hibernate.c3p0.acquire_increment">3</property>
    <property name="hibernate.c3p0.idle_test_period">25200</property>
    <property name="hibernate.c3p0.timeout">1800</property>
    <property name="hibernate.c3p0.max_size">15</property>
    <property name="hibernate.c3p0.min_size">3</property>
    <property name="hibernate.c3p0.max_statements">250</property>

    <property name="hibernate.c3p0.preferredTestQuery">SELECT 1;</property>
    <property name="hibernate.c3p0.testConnectionOnCheckout">true</property>


    <!-- Mapping files -->
            ...
</session-factory>

c3p0.testConnectionOnCheckout=true
c3p0.preferredTestQuery=SELECT 1;
com.mchange.v2.c3p0.management.ManagementCoordinator=com.mchange.v2.c3p0.management.NullManagementCoordinator

我的tomcat
tomcat6/conf/server.xml文件包含：

<Connector port="8080" protocol="AJP/1.3" connectionTimeout="20000" URIEncoding="UTF-8" redirectPort="8443" />

在hibernate.cfg.xml中：

<property name="hibernate.c3p0.idle_test_period">80</property>
<property name="hibernate.c3p0.timeout">60</property>

有什么想法吗？
是否应该等待\u超时>c3p0.idle\u test\u period>c3p0.timeout

10月7日更新：

仍然是相同的超时，但我在我的
log4j.properties
文件中添加了日志信息，以确保c3p0在我的
hibernate.cfg.xml
文件中以所需的值运行，并确保我得到了：

11:13:09,393 INFO MLog:92 - MLog clients using log4j logging.
11:13:09,477 INFO C3P0Registry:216 - Initializing c3p0-0.9.2.1 [built 20-March-2013 11:16:28 +0000; debug? true; trace: 10]
11:13:09,627 INFO AbstractPoolBackedDataSource:522 - Initializing c3p0 pool... com.mchange.v2.c3p0.PoolBackedDataSource@3d0991ef [ connectionPoolDataSource -> com.mchange.v2.c3p0.WrapperConnectionPoolDataSource@b336cd6b [ acquireIncrement -> 1, acquireRetryAttempts -> 30, acquireRetryDelay -> 1000, autoCommitOnClose -> false, automaticTestTable -> null, breakAfterAcquireFailure -> false, checkoutTimeout -> 0, connectionCustomizerClassName -> null, connectionTesterClassName -> com.mchange.v2.c3p0.impl.DefaultConnectionTester, debugUnreturnedConnectionStackTraces -> false, factoryClassLocation -> null, forceIgnoreUnresolvedTransactions -> false, identityToken -> z8kflt8x14i4fy2kk9fga|7eac4d3b, idleConnectionTestPeriod -> 60, initialPoolSize -> 3, maxAdministrativeTaskTime -> 0, maxConnectionAge -> 0, maxIdleTime -> 120, maxIdleTimeExcessConnections -> 0, maxPoolSize -> 25, maxStatements -> 0, maxStatementsPerConnection -> 0, minPoolSize -> 1, nestedDataSource -> com.mchange.v2.c3p0.DriverManagerDataSource@ebdc296f [ description -> null, driverClass -> null, factoryClassLocation -> null, identityToken -> z8kflt8x14i4fy2kk9fga|1fbbc779, jdbcUrl -> jdbc:mysql://localhost:3306/mydb?autoReconnect=true, properties -> {autoReconnect=true, is-connection-validation-required=true, useUnicode=true, user=******, password=******, characterEncoding=UTF-8, autoReconnectForPools=true} ], preferredTestQuery -> select 1;, propertyCycle -> 0, statementCacheNumDeferredCloseThreads -> 0, testConnectionOnCheckin -> false, testConnectionOnCheckout -> false, unreturnedConnectionTimeout -> 0, usesTraditionalReflectiveProxies -> false; userOverrides: {} ], dataSourceName -> null, factoryClassLocation -> null, identityToken -> z8kflt8x14i4fy2kk9fga|27b104d7, numHelperThreads -> 3 ]

也更新到最新的库以防万一，但仍然相同：
c3p0-0.9.2.1.jar，hibernate-c3p0-4.2.6.Final.jar，hibernate-commons-annotations-4.0.2.Final.jar，hibernate-core-4.2.6.Final.jar，mysql-connector-java-5.1.26-bin.jar
这种情况几乎总是由防火墙或其他网络组件关闭空闲连接引起的。解决方案是使用一个连接测试语句，这看起来像是您正在做的。我对
C3P0
一无所知（只是它还没有发布1.0版），所以我无法判断您的配置是否正确，可以防止空闲超时

我想知道你为什么不使用Tomcat的内置连接池。它似乎工作得很好，配置也很好

14:15:41,746 WARN NewPooledConnection:486 - [c3p0] A PooledConnection that has already signalled a Connection error is still in use!
14:15:41,747 WARN NewPooledConnection:487 - [c3p0] Another error has occurred [ com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: No operations allowed after connection closed. ] which will not be reported to listeners!
com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: No operations allowed after connection closed.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:532)
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:1013)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:987)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:982)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:927)
at com.mysql.jdbc.ConnectionImpl.throwConnectionClosedException(ConnectionImpl.java:1205)
at com.mysql.jdbc.ConnectionImpl.checkClosed(ConnectionImpl.java:1197)
at com.mysql.jdbc.ConnectionImpl.prepareStatement(ConnectionImpl.java:4186)
at com.mysql.jdbc.ConnectionImpl.prepareStatement(ConnectionImpl.java:4152)
at sun.reflect.GeneratedMethodAccessor31.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at com.mchange.v2.c3p0.stmt.GooGooStatementCache$1StmtAcquireTask.run(GooGooStatementCache.java:525)
at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:547)
Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet successfully received from the server was 300,078 milliseconds ago. The last packet sent successfully to the server was 18 milliseconds ago.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:532)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1116)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3102)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2991)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3532)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2002)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2163)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2624)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2127)
at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:2293)
at com.mchange.v2.c3p0.impl.NewProxyPreparedStatement.executeQuery(NewProxyPreparedStatement.java:76)
at sun.reflect.GeneratedMethodAccessor37.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at org.hibernate.engine.jdbc.internal.proxy.AbstractStatementProxyHandler.continueInvocation(AbstractStatementProxyHandler.java:122)
at org.hibernate.engine.jdbc.internal.proxy.AbstractProxyHandler.invoke(AbstractProxyHandler.java:81)
at sun.proxy.$Proxy24.executeQuery(Unknown Source)
at org.hibernate.loader.Loader.getResultSet(Loader.java:1962)
at org.hibernate.loader.Loader.doQuery(Loader.java:829)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:289)
at org.hibernate.loader.Loader.doList(Loader.java:2447)
at org.hibernate.loader.Loader.doList(Loader.java:2433)
at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2263)
at org.hibernate.loader.Loader.list(Loader.java:2258)
at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:470)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:355)
at org.hibernate.engine.query.spi.HQLQueryPlan.performList(HQLQueryPlan.java:196)
at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1161)
at org.hibernate.internal.QueryImpl.list(QueryImpl.java:101)
at gr.adds.myapp.server.db.DB.getBFromUser(DB.java:49)
at gr.adds.myapp.server.BSImpl.getBusesInfo(BSImpl.java:57)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:569)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(RemoteServiceServlet.java:208)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(RemoteServiceServlet.java:248)
at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(AbstractRemoteServiceServlet.java:62)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.jk.server.JkCoyoteHandler.invoke(JkCoyoteHandler.java:190)
at org.apache.jk.common.HandlerRequest.invoke(HandlerRequest.java:291)
at org.apache.jk.common.ChannelSocket.invoke(ChannelSocket.java:769)
at org.apache.jk.common.ChannelSocket.processConnection(ChannelSocket.java:698)
at org.apache.jk.common.ChannelSocket$SocketConnection.runIt(ChannelSocket.java:891)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:690)
at java.lang.Thread.run(Thread.java:679)
Caused by: java.io.EOFException: Can not read response from server. Expected to read 4 bytes, read 0 bytes before connection was unexpectedly lost.
at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:2552)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3002)
... 53 more
14:15:41,751 WARN SqlExceptionHelper:143 - SQL Error: 0, SQLState: 08003
14:15:41,752 ERROR SqlExceptionHelper:144 - No operations allowed after connection closed.
org.hibernate.exception.JDBCConnectionException: No operations allowed after connection closed.
at org.hibernate.exception.internal.SQLExceptionTypeDelegate.convert(SQLExceptionTypeDelegate.java:68)
at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:49)
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:125)
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:110)
at org.hibernate.engine.jdbc.internal.proxy.ConnectionProxyHandler.continueInvocation(ConnectionProxyHandler.java:146)
at org.hibernate.engine.jdbc.internal.proxy.AbstractProxyHandler.invoke(AbstractProxyHandler.java:81)
at sun.proxy.$Proxy23.prepareStatement(Unknown Source)
at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$5.doPrepare(StatementPreparerImpl.java:147)
at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$StatementPreparationTemplate.prepareStatement(StatementPreparerImpl.java:166)
at org.hibernate.engine.jdbc.internal.StatementPreparerImpl.prepareQueryStatement(StatementPreparerImpl.java:145)
at org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1720)
at org.hibernate.loader.Loader.doQuery(Loader.java:828)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:289)
at org.hibernate.loader.Loader.doList(Loader.java:2447)
at org.hibernate.loader.Loader.doList(Loader.java:2433)
at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2263)
at org.hibernate.loader.Loader.list(Loader.java:2258)
at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:470)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:355)
at org.hibernate.engine.query.spi.HQLQueryPlan.performList(HQLQueryPlan.java:196)
at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1161)
at org.hibernate.internal.QueryImpl.list(QueryImpl.java:101)
at gr.adds.myapp.server.db.DB.getBFromUser(DB.java:49)
at gr.adds.myapp.server.BSImpl.getBusesInfo(BSImpl.java:57)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:569)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(RemoteServiceServlet.java:208)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(RemoteServiceServlet.java:248)
at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(AbstractRemoteServiceServlet.java:62)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.jk.server.JkCoyoteHandler.invoke(JkCoyoteHandler.java:190)
at org.apache.jk.common.HandlerRequest.invoke(HandlerRequest.java:291)
at org.apache.jk.common.ChannelSocket.invoke(ChannelSocket.java:769)
at org.apache.jk.common.ChannelSocket.processConnection(ChannelSocket.java:698)
at org.apache.jk.common.ChannelSocket$SocketConnection.runIt(ChannelSocket.java:891)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:690)
at java.lang.Thread.run(Thread.java:679)
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: No operations allowed after connection closed.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:532)
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:1013)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:987)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:982)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:927)
at com.mysql.jdbc.ConnectionImpl.throwConnectionClosedException(ConnectionImpl.java:1205)
at com.mysql.jdbc.ConnectionImpl.checkClosed(ConnectionImpl.java:1197)
at com.mysql.jdbc.ConnectionImpl.prepareStatement(ConnectionImpl.java:4186)
at com.mysql.jdbc.ConnectionImpl.prepareStatement(ConnectionImpl.java:4152)
at sun.reflect.GeneratedMethodAccessor31.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at com.mchange.v2.c3p0.stmt.GooGooStatementCache$1StmtAcquireTask.run(GooGooStatementCache.java:525)
at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:547)
Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

11:13:09,393 INFO MLog:92 - MLog clients using log4j logging.
11:13:09,477 INFO C3P0Registry:216 - Initializing c3p0-0.9.2.1 [built 20-March-2013 11:16:28 +0000; debug? true; trace: 10]
11:13:09,627 INFO AbstractPoolBackedDataSource:522 - Initializing c3p0 pool... com.mchange.v2.c3p0.PoolBackedDataSource@3d0991ef [ connectionPoolDataSource -> com.mchange.v2.c3p0.WrapperConnectionPoolDataSource@b336cd6b [ acquireIncrement -> 1, acquireRetryAttempts -> 30, acquireRetryDelay -> 1000, autoCommitOnClose -> false, automaticTestTable -> null, breakAfterAcquireFailure -> false, checkoutTimeout -> 0, connectionCustomizerClassName -> null, connectionTesterClassName -> com.mchange.v2.c3p0.impl.DefaultConnectionTester, debugUnreturnedConnectionStackTraces -> false, factoryClassLocation -> null, forceIgnoreUnresolvedTransactions -> false, identityToken -> z8kflt8x14i4fy2kk9fga|7eac4d3b, idleConnectionTestPeriod -> 60, initialPoolSize -> 3, maxAdministrativeTaskTime -> 0, maxConnectionAge -> 0, maxIdleTime -> 120, maxIdleTimeExcessConnections -> 0, maxPoolSize -> 25, maxStatements -> 0, maxStatementsPerConnection -> 0, minPoolSize -> 1, nestedDataSource -> com.mchange.v2.c3p0.DriverManagerDataSource@ebdc296f [ description -> null, driverClass -> null, factoryClassLocation -> null, identityToken -> z8kflt8x14i4fy2kk9fga|1fbbc779, jdbcUrl -> jdbc:mysql://localhost:3306/mydb?autoReconnect=true, properties -> {autoReconnect=true, is-connection-validation-required=true, useUnicode=true, user=******, password=******, characterEncoding=UTF-8, autoReconnectForPools=true} ], preferredTestQuery -> select 1;, propertyCycle -> 0, statementCacheNumDeferredCloseThreads -> 0, testConnectionOnCheckin -> false, testConnectionOnCheckout -> false, unreturnedConnectionTimeout -> 0, usesTraditionalReflectiveProxies -> false; userOverrides: {} ], dataSourceName -> null, factoryClassLocation -> null, identityToken -> z8kflt8x14i4fy2kk9fga|27b104d7, numHelperThreads -> 3 ]