sessionfactoryutils.java

spring的源代码

	    throws HibernateException, IllegalStateException {

		return doGetSession(sessionFactory, null, null, allowCreate);
	}

	/**
	 * Get a Hibernate Session for the given SessionFactory. Is aware of and will
	 * return any existing corresponding Session bound to the current thread, for
	 * example when using HibernateTransactionManager. Will create a new Session
	 * otherwise, if allowCreate is true.
	 * <p>Same as <code>getSession</code>, but throwing the original HibernateException.
	 * @param sessionFactory Hibernate SessionFactory to create the session with
	 * @param entityInterceptor Hibernate entity interceptor, or <code>null</code> if none
	 * @param jdbcExceptionTranslator SQLExcepionTranslator to use for flushing the
	 * Session on transaction synchronization (can be <code>null</code>)
	 * @param allowCreate if a non-transactional Session should be created when no
	 * transactional Session can be found for the current thread
	 * @return the Hibernate Session
	 * @throws HibernateException if the Session couldn't be created
	 * @throws IllegalStateException if no thread-bound Session found and allowCreate false
	 */
	private static Session doGetSession(
			SessionFactory sessionFactory, Interceptor entityInterceptor,
			SQLExceptionTranslator jdbcExceptionTranslator, boolean allowCreate)
			throws HibernateException, IllegalStateException {

		Assert.notNull(sessionFactory, "No SessionFactory specified");

		SessionHolder sessionHolder = (SessionHolder) TransactionSynchronizationManager.getResource(sessionFactory);
		if (sessionHolder != null && !sessionHolder.isEmpty()) {
			// pre-bound Hibernate Session
			Session session = null;
			if (TransactionSynchronizationManager.isSynchronizationActive() &&
					sessionHolder.doesNotHoldNonDefaultSession()) {
				// Spring transaction management is active ->
				// register pre-bound Session with it for transactional flushing.
				session = sessionHolder.getValidatedSession();
				if (session != null && !sessionHolder.isSynchronizedWithTransaction()) {
					logger.debug("Registering Spring transaction synchronization for existing Hibernate Session");
					TransactionSynchronizationManager.registerSynchronization(
							new SpringSessionSynchronization(sessionHolder, sessionFactory, jdbcExceptionTranslator, false));
					sessionHolder.setSynchronizedWithTransaction(true);
					// Switch to FlushMode.AUTO, as we have to assume a thread-bound Session
					// with FlushMode.NEVER, which needs to allow flushing within the transaction.
					FlushMode flushMode = session.getFlushMode();
					if (FlushMode.NEVER.equals(flushMode) &&
							!TransactionSynchronizationManager.isCurrentTransactionReadOnly()) {
						session.setFlushMode(FlushMode.AUTO);
						sessionHolder.setPreviousFlushMode(flushMode);
					}
				}
			}
			else {
				// No Spring transaction management active -> try JTA transaction synchronization.
				session = getJtaSynchronizedSession(sessionHolder, sessionFactory, jdbcExceptionTranslator);
			}
			if (session != null) {
				return session;
			}
		}

		logger.debug("Opening Hibernate Session");
		Session session = (entityInterceptor != null ?
				sessionFactory.openSession(entityInterceptor) : sessionFactory.openSession());

		// Use same Session for further Hibernate actions within the transaction.
		// Thread object will get removed by synchronization at transaction completion.
		if (TransactionSynchronizationManager.isSynchronizationActive()) {
			// We're within a Spring-managed transaction, possibly from JtaTransactionManager.
			logger.debug("Registering Spring transaction synchronization for new Hibernate Session");
			SessionHolder holderToUse = sessionHolder;
			if (holderToUse == null) {
				holderToUse = new SessionHolder(session);
			}
			else {
				holderToUse.addSession(session);
			}
			if (TransactionSynchronizationManager.isCurrentTransactionReadOnly()) {
				session.setFlushMode(FlushMode.NEVER);
			}
			TransactionSynchronizationManager.registerSynchronization(
					new SpringSessionSynchronization(holderToUse, sessionFactory, jdbcExceptionTranslator, true));
			holderToUse.setSynchronizedWithTransaction(true);
			if (holderToUse != sessionHolder) {
				TransactionSynchronizationManager.bindResource(sessionFactory, holderToUse);
			}
		}
		else {
			// No Spring transaction management active -> try JTA transaction synchronization.
			registerJtaSynchronization(session, sessionFactory, jdbcExceptionTranslator, sessionHolder);
		}

		// Check whether we are allowed to return the Session.
		if (!allowCreate && !isSessionTransactional(session, sessionFactory)) {
			doClose(session);
			throw new IllegalStateException("No Hibernate Session bound to thread, " +
			    "and configuration does not allow creation of non-transactional one here");
		}

		return session;
	}

	/**
	 * Retrieve a Session from the given SessionHolder, potentially from a
	 * JTA transaction synchronization.
	 * @param sessionHolder the SessionHolder to check
	 * @param sessionFactory the SessionFactory to get the JTA TransactionManager from
	 * @param jdbcExceptionTranslator SQLExcepionTranslator to use for flushing the
	 * Session on transaction synchronization (can be <code>null</code>)
	 * @return the associated Session, if any
	 * @throws DataAccessResourceFailureException if the Session couldn't be created
	 */
	private static Session getJtaSynchronizedSession(
	    SessionHolder sessionHolder, SessionFactory sessionFactory,
	    SQLExceptionTranslator jdbcExceptionTranslator) throws DataAccessResourceFailureException {

		// JTA synchronization is only possible with a javax.transaction.TransactionManager.
		// We'll check the Hibernate SessionFactory: If a TransactionManagerLookup is specified
		// in Hibernate configuration, it will contain a TransactionManager reference.
		TransactionManager jtaTm = getJtaTransactionManager(sessionFactory, sessionHolder.getAnySession());
		if (jtaTm != null) {
			// Check whether JTA transaction management is active ->
			// fetch pre-bound Session for the current JTA transaction, if any.
			// (just necessary for JTA transaction suspension, with an individual
			// Hibernate Session per currently active/suspended transaction)
			try {
				int jtaStatus = jtaTm.getStatus();
				if (jtaStatus == Status.STATUS_ACTIVE || jtaStatus == Status.STATUS_MARKED_ROLLBACK) {
					// look for transaction-specific Session
					Transaction jtaTx = jtaTm.getTransaction();
					Session session = sessionHolder.getValidatedSession(jtaTx);
					if (session == null && !sessionHolder.isSynchronizedWithTransaction()) {
						// No transaction-specific Session found: If not already marked as
						// synchronized with transaction, register the default thread-bound
						// Session as JTA-transactional. If there is no default Session,
						// we're a new inner JTA transaction with an outer one being suspended:
						// In that case, we'll return null to trigger opening of a new Session.
						session = sessionHolder.getValidatedSession();
						if (session != null) {
							logger.debug("Registering JTA transaction synchronization for existing Hibernate Session");
							sessionHolder.addSession(jtaTx, session);
							jtaTx.registerSynchronization(
									new JtaSessionSynchronization(
											new SpringSessionSynchronization(
													sessionHolder, sessionFactory, jdbcExceptionTranslator, false),
											jtaTm));
							sessionHolder.setSynchronizedWithTransaction(true);
							// Switch to FlushMode.AUTO, as we have to assume a thread-bound Session
							// with FlushMode.NEVER, which needs to allow flushing within the transaction.
							FlushMode flushMode = session.getFlushMode();
							if (FlushMode.NEVER.equals(flushMode)) {
								session.setFlushMode(FlushMode.AUTO);
								sessionHolder.setPreviousFlushMode(flushMode);
							}
						}
					}
					return session;
				}
				else {
					// No transaction active -> simply return default thread-bound Session, if any
					// (possibly from OpenSessionInViewFilter/Interceptor).
					return sessionHolder.getValidatedSession();
				}
			}
			catch (Exception ex) {
				throw new DataAccessResourceFailureException("Could not check JTA transaction", ex);
			}
		}
		else {
			// No JTA TransactionManager -> simply return default thread-bound Session, if any
			// (possibly from OpenSessionInViewFilter/Interceptor).
			return sessionHolder.getValidatedSession();
		}
	}

	/**
	 * Register a JTA synchronization for the given Session, if any.
	 * @param sessionHolder the existing thread-bound SessionHolder, if any
	 * @param session the Session to register
	 * @param sessionFactory the SessionFactory that the Session was created with
	 * @param jdbcExceptionTranslator SQLExcepionTranslator to use for flushing the
	 * Session on transaction synchronization (can be <code>null</code>)
	 */
	private static void registerJtaSynchronization(Session session, SessionFactory sessionFactory,
			SQLExceptionTranslator jdbcExceptionTranslator, SessionHolder sessionHolder) {

		// JTA synchronization is only possible with a javax.transaction.TransactionManager.
		// We'll check the Hibernate SessionFactory: If a TransactionManagerLookup is specified
		// in Hibernate configuration, it will contain a TransactionManager reference.
		TransactionManager jtaTm = getJtaTransactionManager(sessionFactory, session);
		if (jtaTm != null) {
			try {
				int jtaStatus = jtaTm.getStatus();
				if (jtaStatus == Status.STATUS_ACTIVE || jtaStatus == Status.STATUS_MARKED_ROLLBACK) {
					logger.debug("Registering JTA transaction synchronization for new Hibernate Session");
					javax.transaction.Transaction jtaTx = jtaTm.getTransaction();
					SessionHolder holderToUse = sessionHolder;
					// Register JTA Transaction with existing SessionHolder.
					// Create a new SessionHolder if none existed before.
					if (holderToUse == null) {
						holderToUse = new SessionHolder(jtaTx, session);
					}
					else {
						holderToUse.addSession(jtaTx, session);
					}
					jtaTx.registerSynchronization(
							new JtaSessionSynchronization(
									new SpringSessionSynchronization(
											holderToUse, sessionFactory, jdbcExceptionTranslator, true),
									jtaTm));
					holderToUse.setSynchronizedWithTransaction(true);
					if (holderToUse != sessionHolder) {
						TransactionSynchronizationManager.bindResource(sessionFactory, holderToUse);
					}
				}
			}
			catch (Exception ex) {
				throw new DataAccessResourceFailureException(
						"Could not register synchronization with JTA TransactionManager", ex);
			}
		}
	}


	/**
	 * Get a new Hibernate Session from the given SessionFactory.
	 * Will return a new Session even if there already is a pre-bound
	 * Session for the given SessionFactory.
	 * <p>Within a transaction, this method will create a new Session
	 * that shares the transaction's JDBC Connection. More specifically,
	 * it will use the same JDBC Connection as the pre-bound Hibernate Session.
	 * @param sessionFactory Hibernate SessionFactory to create the session with
	 * @return the new Session
	 */
	public static Session getNewSession(SessionFactory sessionFactory) {
		return getNewSession(sessionFactory, null);
	}

	/**
	 * Get a new Hibernate Session from the given SessionFactory.
	 * Will return a new Session even if there already is a pre-bound
	 * Session for the given SessionFactory.
	 * <p>Within a transaction, this method will create a new Session
	 * that shares the transaction's JDBC Connection. More specifically,
	 * it will use the same JDBC Connection as the pre-bound Hibernate Session.
	 * @param sessionFactory Hibernate SessionFactory to create the session with
	 * @param entityInterceptor Hibernate entity interceptor, or <code>null</code> if none
	 * @return the new Session
	 */
	public static Session getNewSession(SessionFactory sessionFactory, Interceptor entityInterceptor) {
		Assert.notNull(sessionFactory, "No SessionFactory specified");

		try {
			SessionHolder sessionHolder = (SessionHolder) TransactionSynchronizationManager.getResource(sessionFactory);
			if (sessionHolder != null && !sessionHolder.isEmpty()) {
				if (entityInterceptor != null) {
					return sessionFactory.openSession(sessionHolder.getAnySession().connection(), entityInterceptor);
				}
				else {
					return sessionFactory.openSession(sessionHolder.getAnySession().connection());
				}
			}
			else {
				if (entityInterceptor != null) {
					return sessionFactory.openSession(entityInterceptor);
				}
				else {