hibernatetransactionmanager.java

一个关于Spring框架的示例应用程序,简单使用,可以参考.

				setDataSource(sfds);
			}
		}
	}


	protected Object doGetTransaction() {
		HibernateTransactionObject txObject = new HibernateTransactionObject();
		txObject.setSavepointAllowed(isNestedTransactionAllowed());

		if (TransactionSynchronizationManager.hasResource(getSessionFactory())) {
			SessionHolder sessionHolder =
					(SessionHolder) TransactionSynchronizationManager.getResource(getSessionFactory());
			if (logger.isDebugEnabled()) {
				logger.debug("Found thread-bound session [" + sessionHolder.getSession() +
						"] for Hibernate transaction");
			}
			txObject.setSessionHolder(sessionHolder, false);
			if (getDataSource() != null) {
				ConnectionHolder conHolder = (ConnectionHolder)
						TransactionSynchronizationManager.getResource(getDataSource());
				txObject.setConnectionHolder(conHolder);
			}
		}

		return txObject;
	}

	protected boolean isExistingTransaction(Object transaction) {
		return ((HibernateTransactionObject) transaction).hasTransaction();
	}

	protected void doBegin(Object transaction, TransactionDefinition definition) {
		if (getDataSource() != null && TransactionSynchronizationManager.hasResource(getDataSource())) {
			throw new IllegalTransactionStateException(
					"Pre-bound JDBC connection found - HibernateTransactionManager does not support " +
					"running within DataSourceTransactionManager if told to manage the DataSource itself. " +
					"It is recommended to use a single HibernateTransactionManager for all transactions " +
					"on a single DataSource, no matter whether Hibernate or JDBC access.");
		}

		HibernateTransactionObject txObject = (HibernateTransactionObject) transaction;
		if (txObject.getSessionHolder() == null) {
			Session session = SessionFactoryUtils.getSession(
					getSessionFactory(), getEntityInterceptor(), getJdbcExceptionTranslator(), false);
			if (logger.isDebugEnabled()) {
				logger.debug("Opened new session [" + session + "] for Hibernate transaction");
			}
			txObject.setSessionHolder(new SessionHolder(session), true);
		}

		txObject.getSessionHolder().setSynchronizedWithTransaction(true);
		Session session = txObject.getSessionHolder().getSession();

		try {
			Connection con = session.connection();
			Integer previousIsolationLevel = DataSourceUtils.prepareConnectionForTransaction(con, definition);
			txObject.setPreviousIsolationLevel(previousIsolationLevel);

			if (definition.isReadOnly() && txObject.isNewSessionHolder()) {
				// Just set to NEVER in case of a new Session for this transaction.
				session.setFlushMode(FlushMode.NEVER);
			}

			if (!definition.isReadOnly() && !txObject.isNewSessionHolder()) {
				// We need AUTO or COMMIT for a non-read-only transaction.
				FlushMode flushMode = session.getFlushMode();
				if (FlushMode.NEVER.equals(flushMode)) {
					session.setFlushMode(FlushMode.AUTO);
					txObject.getSessionHolder().setPreviousFlushMode(flushMode);
				}
			}

			// Add the Hibernate transaction to the session holder.
			txObject.getSessionHolder().setTransaction(session.beginTransaction());

			// Register transaction timeout.
			if (definition.getTimeout() != TransactionDefinition.TIMEOUT_DEFAULT) {
				txObject.getSessionHolder().setTimeoutInSeconds(definition.getTimeout());
			}

			// Register the Hibernate Session's JDBC Connection for the DataSource, if set.
			if (getDataSource() != null) {
				ConnectionHolder conHolder = new ConnectionHolder(con);
				if (definition.getTimeout() != TransactionDefinition.TIMEOUT_DEFAULT) {
					conHolder.setTimeoutInSeconds(definition.getTimeout());
				}
				if (logger.isDebugEnabled()) {
					logger.debug("Exposing Hibernate transaction as JDBC transaction [" +
							conHolder.getConnection() + "]");
				}
				TransactionSynchronizationManager.bindResource(getDataSource(), conHolder);
				txObject.setConnectionHolder(conHolder);
			}

			// Bind the session holder to the thread.
			if (txObject.isNewSessionHolder()) {
				TransactionSynchronizationManager.bindResource(getSessionFactory(), txObject.getSessionHolder());
			}
		}

		catch (Exception ex) {
			SessionFactoryUtils.closeSessionIfNecessary(session, getSessionFactory());
			throw new CannotCreateTransactionException("Could not create Hibernate transaction", ex);
		}
	}

	protected Object doSuspend(Object transaction) {
		HibernateTransactionObject txObject = (HibernateTransactionObject) transaction;
		txObject.setSessionHolder(null, false);
		SessionHolder sessionHolder =
				(SessionHolder) TransactionSynchronizationManager.unbindResource(getSessionFactory());
		ConnectionHolder connectionHolder = null;
		if (getDataSource() != null) {
			connectionHolder = (ConnectionHolder) TransactionSynchronizationManager.unbindResource(getDataSource());
		}
		return new SuspendedResourcesHolder(sessionHolder, connectionHolder);
	}

	protected void doResume(Object transaction, Object suspendedResources) {
		SuspendedResourcesHolder resourcesHolder = (SuspendedResourcesHolder) suspendedResources;
		if (TransactionSynchronizationManager.hasResource(getSessionFactory())) {
			// From non-transactional code running in active transaction synchronization
			// -> can be safely removed, will be closed on transaction completion.
			TransactionSynchronizationManager.unbindResource(getSessionFactory());
		}
		TransactionSynchronizationManager.bindResource(getSessionFactory(), resourcesHolder.getSessionHolder());
		if (getDataSource() != null) {
			TransactionSynchronizationManager.bindResource(getDataSource(), resourcesHolder.getConnectionHolder());
		}
	}

	protected void doCommit(DefaultTransactionStatus status) {
		HibernateTransactionObject txObject = (HibernateTransactionObject) status.getTransaction();
		if (status.isDebug()) {
			logger.debug("Committing Hibernate transaction on session [" +
					txObject.getSessionHolder().getSession() + "]");
		}
		try {
			txObject.getSessionHolder().getTransaction().commit();
		}
		catch (net.sf.hibernate.TransactionException ex) {
			// assumably from commit call to the underlying JDBC connection
			throw new TransactionSystemException("Could not commit Hibernate transaction", ex);
		}
		catch (JDBCException ex) {
			// assumably failed to flush changes to database
			throw convertJdbcAccessException(ex.getSQLException());
		}
		catch (HibernateException ex) {
			// assumably failed to flush changes to database
			throw convertHibernateAccessException(ex);
		}
	}

	protected void doRollback(DefaultTransactionStatus status) {
		HibernateTransactionObject txObject = (HibernateTransactionObject) status.getTransaction();
		if (status.isDebug()) {
			logger.debug("Rolling back Hibernate transaction on session [" +
					txObject.getSessionHolder().getSession() + "]");
		}
		try {
			txObject.getSessionHolder().getTransaction().rollback();
		}
		catch (net.sf.hibernate.TransactionException ex) {
			throw new TransactionSystemException("Could not roll back Hibernate transaction", ex);
		}
		catch (JDBCException ex) {
			// Shouldn't really happen, as a rollback doesn't cause a flush.
			throw convertJdbcAccessException(ex.getSQLException());
		}
		catch (HibernateException ex) {
			// Shouldn't really happen, as a rollback doesn't cause a flush.
			throw convertHibernateAccessException(ex);
		}
		finally {
			if (!txObject.isNewSessionHolder()) {
				// Clear all pending inserts/updates/deletes in the Session.
				// Necessary for pre-bound Sessions, to avoid inconsistent state.
				txObject.getSessionHolder().getSession().clear();
			}
		}
	}

	protected void doSetRollbackOnly(DefaultTransactionStatus status) {
		HibernateTransactionObject txObject = (HibernateTransactionObject) status.getTransaction();
		if (status.isDebug()) {
			logger.debug("Setting Hibernate transaction on session [" +
					txObject.getSessionHolder().getSession() + "] rollback-only");
		}
		txObject.setRollbackOnly();
	}

	protected void doCleanupAfterCompletion(Object transaction) {
		HibernateTransactionObject txObject = (HibernateTransactionObject) transaction;

		// Remove the session holder from the thread.
		if (txObject.isNewSessionHolder()) {
			TransactionSynchronizationManager.unbindResource(getSessionFactory());
		}

		// Remove the JDBC connection holder from the thread, if set.
		if (getDataSource() != null) {
			TransactionSynchronizationManager.unbindResource(getDataSource());
		}

		try {
			Connection con = txObject.getSessionHolder().getSession().connection();
			DataSourceUtils.resetConnectionAfterTransaction(con, txObject.getPreviousIsolationLevel());
		}
		catch (HibernateException ex) {
			logger.info("Could not access JDBC connection of Hibernate session", ex);
		}

		Session session = txObject.getSessionHolder().getSession();
		if (txObject.isNewSessionHolder()) {
			if (logger.isDebugEnabled()) {
				logger.debug("Closing Hibernate session [" + session + "] after transaction");
			}
			SessionFactoryUtils.closeSessionIfNecessary(session, getSessionFactory());
		}
		else {
			if (logger.isDebugEnabled()) {
				logger.debug("Not closing pre-bound Hibernate session [" + session + "] after transaction");
			}
			if (txObject.getSessionHolder().getPreviousFlushMode() != null) {
				session.setFlushMode(txObject.getSessionHolder().getPreviousFlushMode());
			}
		}
		txObject.getSessionHolder().clear();
	}

	/**
	 * Convert the given HibernateException to an appropriate exception from
	 * the org.springframework.dao hierarchy. Can be overridden in subclasses.
	 * @param ex HibernateException that occured
	 * @return the corresponding DataAccessException instance
	 */
	protected DataAccessException convertHibernateAccessException(HibernateException ex) {
		return SessionFactoryUtils.convertHibernateAccessException(ex);
	}

	/**
	 * Convert the given SQLException to an appropriate exception from the
	 * org.springframework.dao hierarchy. Uses a JDBC exception translater if set,
	 * and a generic HibernateJdbcException else. Can be overridden in subclasses.
	 * @param ex SQLException that occured
	 * @return the corresponding DataAccessException instance
	 * @see #setJdbcExceptionTranslator
	 */
	protected DataAccessException convertJdbcAccessException(SQLException ex) {
		if (getJdbcExceptionTranslator() != null) {
			return getJdbcExceptionTranslator().translate("HibernateTemplate", null, ex);
		}
		else {
			return new HibernateJdbcException(ex);
		}
	}


	/**
	 * Hibernate transaction object, representing a SessionHolder.
	 * Used as transaction object by HibernateTransactionManager.
	 *
	 * <p>Derives from JdbcTransactionObjectSupport to inherit the capability
	 * to manage JDBC 3.0 Savepoints for underlying JDBC Connections.
	 *
	 * @see SessionHolder
	 */
	private static class HibernateTransactionObject extends JdbcTransactionObjectSupport {

		private SessionHolder sessionHolder;

		private boolean newSessionHolder;

		public void setSessionHolder(SessionHolder sessionHolder, boolean newSessionHolder) {
			this.sessionHolder = sessionHolder;
			this.newSessionHolder = newSessionHolder;
		}

		public SessionHolder getSessionHolder() {
			return sessionHolder;
		}

		public boolean isNewSessionHolder() {
			return newSessionHolder;
		}

		public boolean hasTransaction() {
			return (this.sessionHolder != null && this.sessionHolder.getTransaction() != null);
		}

		public void setRollbackOnly() {
			getSessionHolder().setRollbackOnly();
			if (getConnectionHolder() != null) {
				getConnectionHolder().setRollbackOnly();
			}
		}

		public boolean isRollbackOnly() {
			return getSessionHolder().isRollbackOnly() ||
					(getConnectionHolder() != null && getConnectionHolder().isRollbackOnly());
		}
	}


	/**
	 * Holder for suspended resources.
	 * Used internally by doSuspend and doResume.
	 */
	private static class SuspendedResourcesHolder {

		private final SessionHolder sessionHolder;

		private final ConnectionHolder connectionHolder;

		private SuspendedResourcesHolder(SessionHolder sessionHolder, ConnectionHolder conHolder) {
			this.sessionHolder = sessionHolder;
			this.connectionHolder = conHolder;
		}

		private SessionHolder getSessionHolder() {
			return sessionHolder;
		}

		private ConnectionHolder getConnectionHolder() {
			return connectionHolder;
		}
	}

}