hibernatetransactionmanager.java

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		txObject.setConnectionHolder(null);
		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 [" +
					SessionFactoryUtils.toString(txObject.getSessionHolder().getSession()) + "]");
		}
		try {
			txObject.getSessionHolder().getTransaction().commit();
		}
		catch (org.hibernate.TransactionException ex) {
			// assumably from commit call to the underlying JDBC connection
			throw new TransactionSystemException("Could not commit Hibernate transaction", ex);
		}
		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 [" +
					SessionFactoryUtils.toString(txObject.getSessionHolder().getSession()) + "]");
		}
		try {
			txObject.getSessionHolder().getTransaction().rollback();
		}
		catch (org.hibernate.TransactionException ex) {
			throw new TransactionSystemException("Could not roll back Hibernate transaction", ex);
		}
		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 [" +
					SessionFactoryUtils.toString(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 exposed.
		if (getDataSource() != null) {
			TransactionSynchronizationManager.unbindResource(getDataSource());
		}

		Session session = txObject.getSessionHolder().getSession();
		if (this.prepareConnection && session.isConnected() && isSameConnectionForEntireSession(session)) {
			// We're running with connection release mode "on_close": We're able to reset
			// the isolation level and/or read-only flag of the JDBC Connection here.
			// Else, we need to rely on the connection pool to perform proper cleanup.
			try {
				Connection con = session.connection();
				DataSourceUtils.resetConnectionAfterTransaction(con, txObject.getPreviousIsolationLevel());
			}
			catch (HibernateException ex) {
				logger.debug("Could not access JDBC Connection of Hibernate Session", ex);
			}
		}

		if (txObject.isNewSessionHolder()) {
			if (logger.isDebugEnabled()) {
				logger.debug("Closing Hibernate Session [" + SessionFactoryUtils.toString(session) +
						"] after transaction");
			}
			SessionFactoryUtils.closeSessionOrRegisterDeferredClose(session, getSessionFactory());
		}
		else {
			if (logger.isDebugEnabled()) {
				logger.debug("Not closing pre-bound Hibernate Session [" +
						SessionFactoryUtils.toString(session) + "] after transaction");
			}
			if (txObject.getSessionHolder().getPreviousFlushMode() != null) {
				session.setFlushMode(txObject.getSessionHolder().getPreviousFlushMode());
			}
			if (hibernateSetTimeoutAvailable) {
				// Running against Hibernate 3.1+...
				// Let's explicitly disconnect the Session to provide efficient Connection handling
				// even with connection release mode "on_close". The Session will automatically
				// obtain a new Connection in case of further database access.
				// Couldn't do this on Hibernate 3.0, where disconnect required a manual reconnect.
				session.disconnect();
			}
		}
		txObject.getSessionHolder().clear();
	}

	/**
	 * Return whether the given Hibernate Session will always hold the same
	 * JDBC Connection. This is used to check whether the transaction manager
	 * can safely prepare and clean up the JDBC Connection used for a transaction.
	 * <p>Default implementation checks the Session's connection release mode
	 * to be "on_close". Unfortunately, this requires casting to SessionImpl,
	 * as of Hibernate 3.0/3.1. If that cast doesn't work, we'll simply assume
	 * we're safe and return <code>true</code>.
	 * @param session the Hibernate Session to check
	 * @see org.hibernate.impl.SessionImpl#getConnectionReleaseMode()
	 * @see org.hibernate.ConnectionReleaseMode#ON_CLOSE
	 */
	protected boolean isSameConnectionForEntireSession(Session session) {
		if (!(session instanceof SessionImpl)) {
			// The best we can do is to assume we're safe.
			return true;
		}
		ConnectionReleaseMode releaseMode = ((SessionImpl) session).getConnectionReleaseMode();
		return ConnectionReleaseMode.ON_CLOSE.equals(releaseMode);
	}


	/**
	 * Convert the given HibernateException to an appropriate exception
	 * from the <code>org.springframework.dao</code> hierarchy.
	 * <p>Will automatically apply a specified SQLExceptionTranslator to a
	 * Hibernate JDBCException, else rely on Hibernate's default translation.
	 * @param ex HibernateException that occured
	 * @return a corresponding DataAccessException
	 * @see SessionFactoryUtils#convertHibernateAccessException
	 * @see #setJdbcExceptionTranslator
	 */
	protected DataAccessException convertHibernateAccessException(HibernateException ex) {
		if (getJdbcExceptionTranslator() != null && ex instanceof JDBCException) {
			return convertJdbcAccessException((JDBCException) ex, getJdbcExceptionTranslator());
		}
		else if (GenericJDBCException.class.equals(ex.getClass())) {
			return convertJdbcAccessException((GenericJDBCException) ex, getDefaultJdbcExceptionTranslator());
		}
		return SessionFactoryUtils.convertHibernateAccessException(ex);
	}

	/**
	 * Convert the given Hibernate JDBCException to an appropriate exception
	 * from the <code>org.springframework.dao</code> hierarchy, using the
	 * given SQLExceptionTranslator.
	 * @param ex Hibernate JDBCException that occured
	 * @param translator the SQLExceptionTranslator to use
	 * @return a corresponding DataAccessException
	 */
	protected DataAccessException convertJdbcAccessException(JDBCException ex, SQLExceptionTranslator translator) {
		return translator.translate("Hibernate flushing: " + ex.getMessage(), ex.getSQL(), ex.getSQLException());
	}

	/**
	 * Obtain a default SQLExceptionTranslator, lazily creating it if necessary.
	 * <p>Creates a default
	 * {@link org.springframework.jdbc.support.SQLErrorCodeSQLExceptionTranslator}
	 * for the SessionFactory's underlying DataSource.
	 */
	protected synchronized SQLExceptionTranslator getDefaultJdbcExceptionTranslator() {
		if (this.defaultJdbcExceptionTranslator == null) {
			if (getDataSource() != null) {
				this.defaultJdbcExceptionTranslator = new SQLErrorCodeSQLExceptionTranslator(getDataSource());
			}
			else {
				this.defaultJdbcExceptionTranslator = SessionFactoryUtils.newJdbcExceptionTranslator(getSessionFactory());
			}
		}
		return this.defaultJdbcExceptionTranslator;
	}


	/**
	 * Hibernate transaction object, representing a SessionHolder.
	 * Used as transaction object by HibernateTransactionManager.
	 *
	 * <p>Derives from JdbcTransactionObjectSupport in order 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 this.sessionHolder;
		}

		public boolean isNewSessionHolder() {
			return this.newSessionHolder;
		}

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

		public void setRollbackOnly() {
			getSessionHolder().setRollbackOnly();
			if (hasConnectionHolder()) {
				getConnectionHolder().setRollbackOnly();
			}
		}

		public boolean isRollbackOnly() {
			return getSessionHolder().isRollbackOnly() ||
					(hasConnectionHolder() && getConnectionHolder().isRollbackOnly());
		}
	}


	/**
	 * Holder for suspended resources.
	 * Used internally by <code>doSuspend</code> and <code>doResume</code>.
	 */
	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 this.sessionHolder;
		}

		private ConnectionHolder getConnectionHolder() {
			return this.connectionHolder;
		}
	}

}