一尘不染

org.hibernate.exception.GenericJDBCException:无法执行查询

hibernate

我正在使用hibernate3.6.7进行映射。我将连接部分设置为静态。我需要服务程序永远运行,另一个服务将调用该服务的某些方法来查询数据库。当我让该服务运行时,第一天工作良好,但是第二天我调用它时,它给出了:

org.hibernate.exception.GenericJDBCException: could not execute query
    at org.hibernate.exception.SQLStateConverter.handledNonSpecificException(SQLStateConverter.java:140)
    at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:128)
    at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)
    at org.hibernate.loader.Loader.doList(Loader.java:2545)
    at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2276)
    at org.hibernate.loader.Loader.list(Loader.java:2271)
    at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:459)
    at org.hibernate.hql.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:365)
    at org.hibernate.engine.query.HQLQueryPlan.performList(HQLQueryPlan.java:196)
    at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1268)
    at org.hibernate.impl.QueryImpl.list(QueryImpl.java:102)
    at com.myCompany.Query.myMethod(Query.java:99)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at com.sun.jersey.spi.container.JavaMethodInvokerFactory$1.invoke(JavaMethodInvokerFactory.java:60)
    at com.sun.jersey.server.impl.model.method.dispatch.AbstractResourceMethodDispatchProvider$TypeOutInvoker._dispatch(AbstractResourceMethodDispatchProvider.java:185)
    at com.sun.jersey.server.impl.model.method.dispatch.ResourceJavaMethodDispatcher.dispatch(ResourceJavaMethodDispatcher.java:75)
    at com.sun.jersey.server.impl.uri.rules.HttpMethodRule.accept(HttpMethodRule.java:288)
    at com.sun.jersey.server.impl.uri.rules.ResourceClassRule.accept(ResourceClassRule.java:108)
    at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)
    at com.sun.jersey.server.impl.uri.rules.RootResourceClassesRule.accept(RootResourceClassesRule.java:84)
    at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1469)
    at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1400)
    at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1349)
    at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1339)
    at com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:416)
    at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:537)
    at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:699)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
    at org.ebayopensource.ginger.server.internal.container.MessageProcessor.processRequest(MessageProcessor.java:93)
    at org.ebayopensource.ginger.server.container.GingerServletShell.service(GingerServletShell.java:80)
    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:175)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:568)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
    at java.lang.Thread.run(Thread.java:662)
Caused by: java.sql.SQLException: Closed Connection
    at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:112)
    at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:146)
    at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:208)
    at oracle.jdbc.driver.PhysicalConnection.prepareStatement(PhysicalConnection.java:864)
    at oracle.jdbc.driver.PhysicalConnection.prepareStatement(PhysicalConnection.java:783)
    at org.hibernate.jdbc.AbstractBatcher.getPreparedStatement(AbstractBatcher.java:534)
    at org.hibernate.jdbc.AbstractBatcher.getPreparedStatement(AbstractBatcher.java:452)
    at org.hibernate.jdbc.AbstractBatcher.prepareQueryStatement(AbstractBatcher.java:161)
    at org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1700)
    at org.hibernate.loader.Loader.doQuery(Loader.java:801)
    at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:274)
    at org.hibernate.loader.Loader.doList(Loader.java:2542)

似乎连接已关闭。有人可以给我一些建议吗?

非常感谢你:)


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2020-06-20

共1个答案

一尘不染

听起来好像数据库已关闭连接或某个网络设备已终止套接字。您可以通过多种方法来解决此问题:

  1. 您可以经常在连接上发出某种“保持活动”类型的查询(例如:SELECT 1)以使其保持活动状态。假设它由于空闲而关闭。
  2. 您可以经常重新打开连接。
  3. 如果您收到连接关闭异常,则可以重新打开连接。咄。
  4. 您可以使用一个连接池,它可以为您执行保持活动和重新连接。 Apache的DBCP是许多人的最爱。

我推荐最后一个。您将使用DBCP之类的东西:

BasicDataSource ds = new BasicDataSource();
ds.setDriverClassName("oracle.jdbc.driver.OracleDriver");
ds.setUsername("scott");
ds.setPassword("tiger");
ds.setValidationQuery("SELECT 1"); // this is database specific
ds.setTestWhileIdle(true); // test the connections every so often
ds.setUrl(connectURI);
...
while (!shutdown) {
    Connection conn = dataSource.getConnection();
    Statement stmt = conn.createStatement();
    ...
    stmt.close();
    // this returns the connection back to the pool instead of really closing
    // the connection
    conn.close();
}

因此,当需要连接以及完成连接时,您可以Connection绕过BasicDataSourceand调用getConnection(),而不必绕过a
conn.close()。池执行所有验证工作,等等。它还将允许多个线程使用数据库。

希望这可以帮助。


编辑:
您也不能长时间保持hibernate会话。为了向您展示会话的寿命,我将引用文档中的内容:

会话的生命周期受逻辑事务的开始和结束的限制。(长事务可能跨越多个数据库事务。)

会话拥有一个数据库连接,因此您永远都不想保持它一段时间。您应该执行几个数据库请求(例如具有查询和更新的单个Web请求),然后关闭会话,以便可以将基础数据库连接返回到池中。

2020-06-20