Question

我必须保留在@Transactional Controller中打开的ResultSet，以便在MessageConverter中使用。为此，我配置了以下内容：

MVC拦截器：

<mvc:interceptors>
   <bean class="org.springframework.orm.hibernate4.support.OpenSessionInViewInterceptor" 
         p:sessionFactory-ref="sessionFactory"/>
</mvc:interceptors>

：

<bean id="sessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean"
  <property name="hibernateProperties">
    <props>
      <prop key="hibernate.connection.release_mode">on_close</prop>
      ....
    </props>
  </property>
</bean>

：

session.doWork((con) -> { con.setHoldability(HOLD_CURSORS_OVER_COMMIT); });

然而PSQLException: This ResultSet is closed.仍然存在。当事务提交控制器方法返回时，这是日志中的相关片段：

TRACE o.h.e.j.i.JdbcCoordinatorImpl - Registering result set [org.apache.tomcat.dbcp.dbcp2.DelegatingResultSet@5a63c2aa] 
DEBUG o.h.e.t.s.AbstractTransactionImpl - committing 
TRACE o.h.internal.SessionImpl - Automatically flushing session 
TRACE o.h.internal.SessionImpl - before transaction completion 
DEBUG o.h.e.t.i.j.JdbcTransaction - committed JDBC Connection 
DEBUG o.h.e.t.i.j.JdbcTransaction - re-enabling autocommit 
TRACE o.h.e.t.i.TransactionCoordinatorImpl - after transaction completion 
TRACE o.h.internal.SessionImpl - after transaction completion 
TRACE o.h.internal.SessionImpl - Setting flush mode to: MANUAL 
DEBUG o.h.internal.SessionImpl - Disconnecting session 
TRACE o.h.e.j.i.JdbcCoordinatorImpl - Releasing JDBC container resources [org.hibernate.engine.jdbc.internal.JdbcCoordinatorImpl@97bfa5f] 
TRACE o.h.e.j.i.JdbcCoordinatorImpl - Closing result set [org.apache.tomcat.dbcp.dbcp2.DelegatingResultSet@5a63c2aa] 
TRACE o.h.e.j.i.JdbcCoordinatorImpl - Closing prepared statement [select...] 
DEBUG o.h.e.j.i.LogicalConnectionImpl - Releasing JDBC connection 
DEBUG o.h.e.j.i.LogicalConnectionImpl - Released JDBC connection 
DEBUG o.h.e.j.s.SqlExceptionHelper - could not advance using next() [n/a] org.postgresql.util.PSQLException: This ResultSet is closed.

我能做些什么来阻止这种情况发生吗？

Answer 1

默认情况下，Spring会自行管理Hibernate会话。正如HibernateTransactionManager Javadoc中所记录的那样，其中一个后果是Spring将明确调用session.disconnect()，这将使您的connection.release_mode=on_close设置无效。要将此行为更改为Hibernate管理的会话，请务必将hibernateManagedSession上的HibernateTransactionManager属性设置为true：

<bean id="transactionManager" 
   class="org.springframework.orm.hibernate4.HibernateTransactionManager"
   p:hibernateManagedSession="true" />

这样做必然会干扰某些采用默认行为的机制。其中之一是通过TransactionTemplate进行事务管理：不会自动创建Hibernate会话。这可以通过将会话显式绑定到当前线程来修复，最好在TransactionTemplate的子类中捕获：

@Component
public class HibernateTransactionTemplate extends TransactionTemplate
{
  @Autowired private SessionFactory sf;

  @Autowired @Override public void setTransactionManager(PlatformTransactionManager txm) {
    super.setTransactionManager(txm);
  }

  @Override public <T> T execute(TransactionCallback<T> action) throws TransactionException {
    final Session ses = sf.openSession();
    TransactionSynchronizationManager.bindResource(sf, new SessionHolder(ses));
    try { return super.execute(action); }
    finally {
      ses.close();
      TransactionSynchronizationManager.unbindResource(sf);
    }
  }
}

防止在事务提交时关闭ResultSet

1 个答案: