Java class 调用使用休眠的方法 - 多次运行时出错

Question

我有一个带有 servlet 的 Web 应用程序，它调用 java 方法使用休眠在我的数据库中执行插入操作。

SessionFactory sessionFactory = HibernateUtilities.getSessionFactory();
Session session = sessionFactory.openSession(); //This line triggers the exception
session.beginTransaction();
.
.
.
session.save(purchase);
session.getTransaction().commit();
session.close();
sessionFactory.close();

我第一次在网页上提交表单，所有的信息都经过并进入数据库，如果我在不重启的情况下再次提交tomcat，那么我会得到这个异常：

SEVERE: Servlet.service() for servlet [GasPurchaseServlet] in context with path [/CarDB] threw exception
org.hibernate.service.UnknownServiceException: Unknown service requested [org.hibernate.engine.jdbc.connections.spi.ConnectionProvider]
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:201)
    at org.hibernate.internal.AbstractSessionImpl.getJdbcConnectionAccess(AbstractSessionImpl.java:341)
    at org.hibernate.engine.jdbc.internal.JdbcCoordinatorImpl.<init>(JdbcCoordinatorImpl.java:114)
    at org.hibernate.engine.transaction.internal.TransactionCoordinatorImpl.<init>(TransactionCoordinatorImpl.java:89)
    at org.hibernate.internal.SessionImpl.<init>(SessionImpl.java:258)
    at org.hibernate.internal.SessionFactoryImpl$SessionBuilderImpl.openSession(SessionFactoryImpl.java:1589)
    at org.hibernate.internal.SessionFactoryImpl.openSession(SessionFactoryImpl.java:999)
    at [packageName].Main.[methodName](Main.java:95)
    at [packageName].[ServletName].doPost([ServletName].java:83)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:647)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1008)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:745)

看来我一定是在会话或会话工厂或事务上做错了，没有正确关闭。

Answer 1

sessionfactory 在使用后不应关闭。 as per hibernate doc of SessionFactory:

The main contract here is the creation of Session instances. Usually an application has a single SessionFactory instance and threads servicing client requests obtain Session instances from this factory.

Java class 调用使用休眠的方法 - 多次运行时出错

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Java class 调用使用休眠的方法 - 多次 运行 时出错

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Java class 调用使用休眠的方法 - 多次运行时出错