sessionimpl.java

一个Java持久层类库

	public Iterator iterate(String query, QueryParameters queryParameters) throws HibernateException {
		errorIfClosed();
		checkTransactionSynchStatus();
		queryParameters.validateParameters();
		HQLQueryPlan plan = getHQLQueryPlan( query, true );
		autoFlushIfRequired( plan.getQuerySpaces() );

		dontFlushFromFind++; //stops flush being called multiple times if this method is recursively called
		try {
			return plan.performIterate( queryParameters, this );
		}
		finally {
			dontFlushFromFind--;
		}
	}

	public ScrollableResults scroll(String query, QueryParameters queryParameters) throws HibernateException {
		errorIfClosed();
		checkTransactionSynchStatus();
		HQLQueryPlan plan = getHQLQueryPlan( query, false );
		autoFlushIfRequired( plan.getQuerySpaces() );
		dontFlushFromFind++;
		try {
			return plan.performScroll( queryParameters, this );
		}
		finally {
			dontFlushFromFind--;
		}
	}

	public int delete(String query) throws HibernateException {
		return delete( query, ArrayHelper.EMPTY_OBJECT_ARRAY, ArrayHelper.EMPTY_TYPE_ARRAY );
	}

	public int delete(String query, Object value, Type type) throws HibernateException {
		return delete( query, new Object[]{value}, new Type[]{type} );
	}

	public int delete(String query, Object[] values, Type[] types) throws HibernateException {
		errorIfClosed();
		checkTransactionSynchStatus();
		if ( query == null ) {
			throw new IllegalArgumentException("attempt to perform delete-by-query with null query");
		}

		if ( log.isTraceEnabled() ) {
			log.trace( "delete: " + query );
			if ( values.length != 0 ) {
				log.trace( "parameters: " + StringHelper.toString( values ) );
			}
		}

		List list = find( query, values, types );
		int deletionCount = list.size();
		for ( int i = 0; i < deletionCount; i++ ) {
			delete( list.get( i ) );
		}

		return deletionCount;
	}

	public Query createFilter(Object collection, String queryString) {
		errorIfClosed();
		checkTransactionSynchStatus();
		CollectionFilterImpl filter = new CollectionFilterImpl(
				queryString,
		        collection,
		        this,
		        getFilterQueryPlan( collection, queryString, null, false ).getParameterMetadata()
		);
		filter.setComment( queryString );
		return filter;
	}
	
	public Query getNamedQuery(String queryName) throws MappingException {
		errorIfClosed();
		checkTransactionSynchStatus();
		return super.getNamedQuery(queryName);
	}

	public Object instantiate(String entityName, Serializable id) throws HibernateException {
		return instantiate( factory.getEntityPersister(entityName), id );
	}

	/**
	 * give the interceptor an opportunity to override the default instantiation
	 */
	public Object instantiate(EntityPersister persister, Serializable id) throws HibernateException {
		errorIfClosed();
		checkTransactionSynchStatus();
		Object result = interceptor.instantiate( persister.getEntityName(), entityMode, id );
		if ( result == null ) {
			result = persister.instantiate( id, entityMode );
		}
		return result;
	}

	public EntityMode getEntityMode() {
		checkTransactionSynchStatus();
		return entityMode;
	}

	public void setFlushMode(FlushMode flushMode) {
		errorIfClosed();
		checkTransactionSynchStatus();
		if ( log.isTraceEnabled() ) {
			log.trace("setting flush mode to: " + flushMode);
		}
		this.flushMode = flushMode;
	}
	
	public FlushMode getFlushMode() {
		checkTransactionSynchStatus();
		return flushMode;
	}

	public CacheMode getCacheMode() {
		checkTransactionSynchStatus();
		return cacheMode;
	}
	
	public void setCacheMode(CacheMode cacheMode) {
		errorIfClosed();
		checkTransactionSynchStatus();
		if ( log.isTraceEnabled() ) {
			log.trace("setting cache mode to: " + cacheMode);
		}
		this.cacheMode= cacheMode; 
	}

	public Transaction getTransaction() throws HibernateException {
		errorIfClosed();
		return jdbcContext.getTransaction();
	}
	
	public Transaction beginTransaction() throws HibernateException {
		errorIfClosed();
		if ( rootSession != null ) {
			// todo : should seriously consider not allowing a txn to begin from a child session
			//      can always route the request to the root session...
			log.warn( "Transaction started on non-root session" );
		}
		Transaction result = getTransaction();
		result.begin();
		return result;
	}
	
	public void afterTransactionBegin(Transaction tx) {
		errorIfClosed();
		interceptor.afterTransactionBegin(tx);
	}

	public EntityPersister getEntityPersister(final String entityName, final Object object) {
		errorIfClosed();
		if (entityName==null) {
			return factory.getEntityPersister( guessEntityName( object ) );
		}
		else {
			// try block is a hack around fact that currently tuplizers are not
			// given the opportunity to resolve a subclass entity name.  this
			// allows the (we assume custom) interceptor the ability to
			// influence this decision if we were not able to based on the
			// given entityName
			try {
				return factory.getEntityPersister( entityName )
						.getSubclassEntityPersister( object, getFactory(), entityMode );
			}
			catch( HibernateException e ) {
				try {
					return getEntityPersister( null, object );
				}
				catch( HibernateException e2 ) {
					throw e;
				}
			}
		}
	}

	// not for internal use:
	public Serializable getIdentifier(Object object) throws HibernateException {
		errorIfClosed();
		checkTransactionSynchStatus();
		if ( object instanceof HibernateProxy ) {
			LazyInitializer li = ( (HibernateProxy) object ).getHibernateLazyInitializer();
			if ( li.getSession() != this ) {
				throw new TransientObjectException( "The proxy was not associated with this session" );
			}
			return li.getIdentifier();
		}
		else {
			EntityEntry entry = persistenceContext.getEntry(object);
			if ( entry == null ) {
				throw new TransientObjectException( "The instance was not associated with this session" );
			}
			return entry.getId();
		}
	}

	/**
	 * Get the id value for an object that is actually associated with the session. This
	 * is a bit stricter than getEntityIdentifierIfNotUnsaved().
	 */
	public Serializable getContextEntityIdentifier(Object object) {
		errorIfClosed();
		if ( object instanceof HibernateProxy ) {
			return getProxyIdentifier(object);
		}
		else {
			EntityEntry entry = persistenceContext.getEntry(object);
			return entry != null ? entry.getId() : null;
		}
	}
	
	private Serializable getProxyIdentifier(Object proxy) {
		return ( (HibernateProxy) proxy ).getHibernateLazyInitializer().getIdentifier();
	}

	public Collection filter(Object collection, String filter) throws HibernateException {
		return listFilter( collection, filter, new QueryParameters( new Type[1], new Object[1] ) );
	}

	public Collection filter(Object collection, String filter, Object value, Type type) throws HibernateException {
		return listFilter( collection, filter, new QueryParameters( new Type[]{null, type}, new Object[]{null, value} ) );
	}

	public Collection filter(Object collection, String filter, Object[] values, Type[] types) 
	throws HibernateException {
		Object[] vals = new Object[values.length + 1];
		Type[] typs = new Type[types.length + 1];
		System.arraycopy( values, 0, vals, 1, values.length );
		System.arraycopy( types, 0, typs, 1, types.length );
		return listFilter( collection, filter, new QueryParameters( typs, vals ) );
	}

	private FilterQueryPlan getFilterQueryPlan(
			Object collection,
			String filter,
			QueryParameters parameters,
			boolean shallow) throws HibernateException {
		if ( collection == null ) {
			throw new NullPointerException( "null collection passed to filter" );
		}

		CollectionEntry entry = persistenceContext.getCollectionEntryOrNull( collection );
		final CollectionPersister roleBeforeFlush = (entry == null) ? null : entry.getLoadedPersister();

		FilterQueryPlan plan = null;
		if ( roleBeforeFlush == null ) {
			// if it was previously unreferenced, we need to flush in order to
			// get its state into the database in order to execute query
			flush();
			entry = persistenceContext.getCollectionEntryOrNull( collection );
			CollectionPersister roleAfterFlush = (entry == null) ? null : entry.getLoadedPersister();
			if ( roleAfterFlush == null ) {
				throw new QueryException( "The collection was unreferenced" );
			}
			plan = factory.getQueryPlanCache().getFilterQueryPlan( filter, roleAfterFlush.getRole(), shallow, getEnabledFilters() );
		}
		else {
			// otherwise, we only need to flush if there are in-memory changes
			// to the queried tables
			plan = factory.getQueryPlanCache().getFilterQueryPlan( filter, roleBeforeFlush.getRole(), shallow, getEnabledFilters() );
			if ( autoFlushIfRequired( plan.getQuerySpaces() ) ) {
				// might need to run a different filter entirely after the flush
				// because the collection role may have changed
				entry = persistenceContext.getCollectionEntryOrNull( collection );
				CollectionPersister roleAfterFlush = (entry == null) ? null : entry.getLoadedPersister();
				if ( roleBeforeFlush != roleAfterFlush ) {
					if ( roleAfterFlush == null ) {
						throw new QueryException( "The collection was dereferenced" );
					}
					plan = factory.getQueryPlanCache().getFilterQueryPlan( filter, roleAfterFlush.getRole(), shallow, getEnabledFilters() );
				}
			}
		}

		if ( parameters != null ) {
			parameters.getPositionalParameterValues()[0] = entry.getLoadedKey();
			parameters.getPositionalParameterTypes()[0] = entry.getLoadedPersister().getKeyType();
		}

		return plan;
	}

	public List listFilter(Object collection, String filter, QueryParameters queryParameters) 
	throws HibernateException {
		errorIfClosed();
		checkTransactionSynchStatus();
		FilterQueryPlan plan = getFilterQueryPlan( collection, filter, queryParameters, false );
		List results = CollectionHelper.EMPTY_LIST;

		boolean success = false;
		dontFlushFromFind++;   //stops flush being called multiple times if this method is recursively called
		try {
			results = plan.performList( queryParameters, this );
			success = true;
		}
		finally {
			dontFlushFromFind--;
			afterOperation(success);
		}
		return results;
	}

	public Iterator iterateFilter(Object collection, String filter, QueryParameters queryParameters) 
	throws HibernateException {
		errorIfClosed();
		checkTransactionSynchStatus();
		FilterQueryPlan plan = getFilterQueryPlan( collection, filter, queryParameters, true );
		return plan.performIterate( queryParameters, this );
	}

	public Criteria createCriteria(Class persistentClass, String alias) {
		errorIfClosed();
		checkTransactionSynchStatus();
		return new CriteriaImpl( persistentClass.getName(), alias, this );
	}

	public Criteria createCriteria(String entityName, String alias) {
		errorIfClosed();
		checkTransactionSynchStatus();
		return new CriteriaImpl(entityName, alias, this);
	}

	public Criteria createCriteria(Class persistentClass) {
		errorIfClosed();
		checkTransactionSynchStatus();
		return new CriteriaImpl( persistentClass.getName(), this );
	}

	public Criteria createCriteria(String entityName) {
		errorIfClosed();
		checkTransactionSynchStatus();
		return new CriteriaImpl(entityName, this);
	}

	public ScrollableResults scroll(CriteriaImpl criteria, ScrollMode scrollMode) {
		errorIfClosed();
		checkTransactionSynchStatus();
		String entityName = criteria.getEntityOrClassName();
		CriteriaLoader loader = new CriteriaLoader(
				getOuterJoinLoadable(entityName),
				factory,
				criteria,
				entityName,
				getEnabledFilters()
		);
		autoFlushIfRequired( loader.getQuerySpaces() );
		dontFlushFromFind++;
		try {
			return loader.scroll(this, scrollMode);
		}
		finally {
			dontFlushFromFind--;
		}
	}

	public List list(CriteriaImpl criteria) throws HibernateException {
		errorIfClosed();
		checkTransactionSynchStatus();
		String[] implementors = factory.getImplementors( criteria.getEntityOrClassName() );
		int size = implementors.length;

		CriteriaLoader[] loaders = new CriteriaLoader[size];
		Set spaces = new HashSet();
		for( int i=0; i <size; i++ ) {

			loaders[i] = new CriteriaLoader(
					getOuterJoinLoadable( implementors[i] ),
					factory,
					criteria,
					implementors[i],
					getEnabledFilters()
				);

			spaces.addAll( loaders[i].getQuerySpaces() );

		}

		autoFlushIfRequired(spaces);

		List results = Collections.EMPTY_LIST;
		dontFlushFromFind++;
		boolean success = false;
		try {
			for( int i=0; i<size; i++ ) {
				final List currentResults = loaders[i].list(this);
				currentResults.addAll(results);
				results = currentResults;
			}
			success = true;
		}
		finally {
			dontFlushFromFind--;