pathexpressionparser.java

一个Java持久层类库

	private PropertyMapping getPropertyMapping() {
		return currentPropertyMapping;
	}

	private void setType() throws QueryException {
		if ( currentProperty == null ) {
			type = getPropertyMapping().getType();
		}
		else {
			type = getPropertyType();
		}
	}

	protected Type getPropertyType() throws QueryException {
		String propertyPath = getPropertyPath();
		Type propertyType = getPropertyMapping().toType( propertyPath );
		if ( propertyType == null ) {
			throw new QueryException( "could not resolve property type: " + propertyPath );
		}
		return propertyType;
	}

	protected String[] currentColumns() throws QueryException {
		String propertyPath = getPropertyPath();
		String[] propertyColumns = getPropertyMapping().toColumns( currentName, propertyPath );
		if ( propertyColumns == null ) {
			throw new QueryException( "could not resolve property columns: " + propertyPath );
		}
		return propertyColumns;
	}

	private void reset(QueryTranslatorImpl q) {
		//join = q.createJoinFragment(useThetaStyleJoin);
		dotcount = 0;
		currentName = null;
		currentProperty = null;
		collectionName = null;
		collectionRole = null;
		componentPath.setLength( 0 );
		type = null;
		collectionName = null;
		columns = null;
		expectingCollectionIndex = false;
		continuation = false;
		currentPropertyMapping = null;
	}

	public void start(QueryTranslatorImpl q) {
		if ( !continuation ) {
			reset( q );
			path.setLength( 0 );
			joinSequence = new JoinSequence( q.getFactory() ).setUseThetaStyle( useThetaStyleJoin );
		}
	}

	public void end(QueryTranslatorImpl q) throws QueryException {
		ignoreInitialJoin = false;

		Type propertyType = getPropertyType();
		if ( propertyType != null && propertyType.isCollectionType() ) {
			collectionRole = ( ( CollectionType ) propertyType ).getRole();
			collectionName = q.createNameForCollection( collectionRole );
			prepareForIndex( q );
		}
		else {
			columns = currentColumns();
			setType();
		}

		//important!!
		continuation = false;

	}

	private void prepareForIndex(QueryTranslatorImpl q) throws QueryException {

		QueryableCollection collPersister = q.getCollectionPersister( collectionRole );

		if ( !collPersister.hasIndex() ) throw new QueryException( "unindexed collection before []: " + path );
		String[] indexCols = collPersister.getIndexColumnNames();
		if ( indexCols.length != 1 ) throw new QueryException( "composite-index appears in []: " + path );
		//String[] keyCols = collPersister.getKeyColumnNames();

		JoinSequence fromJoins = new JoinSequence( q.getFactory() )
				.setUseThetaStyle( useThetaStyleJoin )
				.setRoot( collPersister, collectionName )
				.setNext( joinSequence.copy() );

		if ( !continuation ) addJoin( collectionName, collPersister.getCollectionType() );

		joinSequence.addCondition( collectionName + '.' + indexCols[0] + " = " ); //TODO: get SQL rendering out of here

		CollectionElement elem = new CollectionElement();
		elem.elementColumns = collPersister.getElementColumnNames(collectionName);
		elem.elementType = collPersister.getElementType();
		elem.isOneToMany = collPersister.isOneToMany();
		elem.alias = collectionName;
		elem.joinSequence = joinSequence;
		collectionElements.addLast( elem );
		setExpectingCollectionIndex();

		q.addCollection( collectionName, collectionRole );
		q.addFromJoinOnly( collectionName, fromJoins );
	}

	static final class CollectionElement {
		Type elementType;
		boolean isOneToMany;
		String alias;
		String[] elementColumns;
		JoinSequence joinSequence;
		StringBuffer indexValue = new StringBuffer();
	}

	public CollectionElement lastCollectionElement() {
		return ( CollectionElement ) collectionElements.removeLast();
	}

	public void setLastCollectionElementIndexValue(String value) {
		( ( CollectionElement ) collectionElements.getLast() ).indexValue.append( value );
	}

	public boolean isExpectingCollectionIndex() {
		return expectingCollectionIndex;
	}

	protected void setExpectingCollectionIndex() throws QueryException {
		expectingCollectionIndex = true;
	}

	public JoinSequence getWhereJoin() {
		return joinSequence;
	}

	public String getWhereColumn() throws QueryException {
		if ( columns.length != 1 ) {
			throw new QueryException( "path expression ends in a composite value: " + path );
		}
		return columns[0];
	}

	public String[] getWhereColumns() {
		return columns;
	}

	public Type getWhereColumnType() {
		return type;
	}

	public String getName() {
		return currentName == null ? collectionName : currentName;
	}


	public String getCollectionSubquery(Map enabledFilters) throws QueryException {
		return CollectionSubqueryFactory.createCollectionSubquery( joinSequence, enabledFilters, currentColumns() );
	}

	public boolean isCollectionValued() throws QueryException {
		//TODO: is there a better way?
		return collectionName != null && !getPropertyType().isCollectionType();
	}

	public void addAssociation(QueryTranslatorImpl q) throws QueryException {
		q.addJoin( getName(), joinSequence );
	}

	public String addFromAssociation(QueryTranslatorImpl q) throws QueryException {
		if ( isCollectionValued() ) {
			return addFromCollection( q );
		}
		else {
			q.addFrom( currentName, joinSequence );
			return currentName;
		}
	}

	public String addFromCollection(QueryTranslatorImpl q) throws QueryException {
		Type collectionElementType = getPropertyType();

		if ( collectionElementType == null ) {
			throw new QueryException( "must specify 'elements' for collection valued property in from clause: " + path );
		}

		if ( collectionElementType.isEntityType() ) {
			// an association
			QueryableCollection collectionPersister = q.getCollectionPersister( collectionRole );
			Queryable entityPersister = ( Queryable ) collectionPersister.getElementPersister();
			String clazz = entityPersister.getEntityName();

			final String elementName;
			if ( collectionPersister.isOneToMany() ) {
				elementName = collectionName;
				//allow index() function:
				q.decoratePropertyMapping( elementName, collectionPersister );
			}
			else { //many-to-many
				q.addCollection( collectionName, collectionRole );
				elementName = q.createNameFor( clazz );
				addJoin( elementName, ( AssociationType ) collectionElementType );
			}
			q.addFrom( elementName, clazz, joinSequence );
			currentPropertyMapping = new CollectionPropertyMapping( collectionPersister );
			return elementName;
		}
		else {
			// collections of values
			q.addFromCollection( collectionName, collectionRole, joinSequence );
			return collectionName;
		}

	}

	String getCollectionName() {
		return collectionName;
	}

	String getCollectionRole() {
		return collectionRole;
	}

	String getCollectionOwnerName() {
		return collectionOwnerName;
	}

	String getOneToOneOwnerName() {
		return oneToOneOwnerName;
	}

	AssociationType getOwnerAssociationType() {
		return ownerAssociationType;
	}

	String getCurrentProperty() {
		return currentProperty;
	}

	String getCurrentName() {
		return currentName;
	}

	public void fetch(QueryTranslatorImpl q, String entityName) throws QueryException {
		if ( isCollectionValued() ) {
			q.setCollectionToFetch( getCollectionRole(), getCollectionName(), getCollectionOwnerName(), entityName );
		}
		else {
			q.addEntityToFetch( entityName, getOneToOneOwnerName(), getOwnerAssociationType() );
		}
	}
}