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一周以来，我一直遇到 Hibernate 和 Mysql 超时错误的问题。显然，在我的 Hibernate/MySQL 运行 8 小时后（这是 Mysql 中的默认超时值），我有例外。我还添加了 c3p0。但这无济于事。

请指教 非常感谢

这是我的休眠配置：

<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
<!--Account MYSQL Username Info-->
<property name="hibernate.connection.url">jdbc:mysql://localhost/reddragon_test?autoReconnect=true</property>
<property name="hibernate.show_sql">true</property>
<property name="transaction.factory_class">org.hibernate.transaction.JDBCTransactionFactory</property>
<property name="current_session_context_class">thread</property>

<property name="hibernate.c3p0.acquire_increment">3</property>
<property name="hibernate.c3p0.idle_test_period">10</property>
<property name="hibernate.c3p0.timeout">10</property>
<property name="hibernate.c3p0.max_size">15</property>
<property name="hibernate.c3p0.min_size">3</property>
<property name="hibernate.c3p0.max_statements">0</property>
<property name="hibernate.c3p0.preferredTestQuery">select 1;</property>

这是跟踪：

org.hibernate.exception.JDBCConnectionException: could not execute query
    at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:74)
    at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43)
    at org.hibernate.loader.Loader.doList(Loader.java:2223)
    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 com.billing.dao.VmplanDAO.findByExample(VmplanDAO.java:178)
    at com.billing.action.getVmplans.processRequest(getVmplans.java:37)
    at com.billing.action.getVmplans.doGet(getVmplans.java:91)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
    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.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:390)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
    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.coyote.http11.Http11Processor.process(Http11Processor.java:852)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
    at java.lang.Thread.run(Thread.java:619)
Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

Last packet sent to the server was 0 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 com.mchange.v2.c3p0.impl.NewProxyPreparedStatement.executeQuery(NewProxyPreparedStatement.java:76)
    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)
    ... 25 more
Caused by: java.net.SocketException: Software caused connection abort: recv failed
    at java.net.SocketInputStream.socketRead0(Native Method)
    at java.net.SocketInputStream.read(SocketInputStream.java:129)
    at com.mysql.jdbc.util.ReadAheadInputStream.fill(ReadAheadInputStream.java:113)
    at com.mysql.jdbc.util.ReadAheadInputStream.readFromUnderlyingStreamIfNecessary(ReadAheadInputStream.java:160)
    at com.mysql.jdbc.util.ReadAheadInputStream.read(ReadAheadInputStream.java:188)
    at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:2428)
    at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2882)
    ... 38 more
java.lang.NullPointerException
java.lang.NullPointerException
    at com.billing.action.getVmplans.processRequest(getVmplans.java:38)
    at com.billing.action.getVmplans.doGet(getVmplans.java:91)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
    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.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:390)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
    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.coyote.http11.Http11Processor.process(Http11Processor.java:852)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
    at java.lang.Thread.run(Thread.java:619)
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1 回答 1

1

老实说，您的问题有三个解决方案。我将解释每种解决方案以及每种解决方案的优缺点（最后会谈到你的情况）

  1. 在 mysql my.ini 文件中配置 wait_time_out 属性以确保您的连接超时。这种方法肯定会奏效，但这绝不是一个好的解决方案。你会喜欢在你的应用程序而不是数据库中处理这个事情，因为有时你可能对数据库没有太多的控制权，或者其他一些应用程序可能正在使用同一个数据库。

  2. 使用 apache dbcp 而不是 c3p0。您可以在您提供数据库名称的服务器的 context.xml 中配置 dbcp。这种方法会起作用，但这种方法的问题是您可能计划将来切换到其他一些应用程序服务器，比如 JBOSS，在这种情况下，我不是 apache dbcp 是否可以工作。我没有用 jboss 尝试过，但我猜它不会。

  3. 第三种方式是您选择的方式

在您的情况下，您缺少一个属性，即

<property name="connection.provider_class">
  org.hibernate.connection.C3P0ConnectionProvider
</property>

到目前为止，您必须在服务器启动期间注意到 c3p0 根本没有初始化。好吧，如果您在设置此属性后考虑您的代码将起作用，我很遗憾地说，它不会。

这是由于弹簧代码中的错误。您可以通过查看 LocalSessionFactoryBean 的源代码来验证这一点，它只是忽略上面设置的属性值并将其设置为 LocalDataSourceConnectionProvider 并且您的 c3p0 永远不会初始化。

您可以提供 LocalSessionFactoryBean 的自定义实现，您可以在其中将提供程序类硬编码为 C3P0ConnectionProvider。

现在重新启动服务器并注意您的 c3p0 已初始化，现在您可以处理 c3p0 详细信息。

到目前为止，您遇到的问题是 c3p0 从未初始化并且不在画面中。

希望这可以帮助。

于 2010-06-28T16:19:18.553 回答