dotnode.java

介绍了hibernate的入门有一些基本常用的事例

	}

	private boolean unresolvedComponent(boolean generateJoin) {
		AST c = getFirstChild();
		if ( generateJoin && isDotNode( c ) ) {
			DotNode dot = ( DotNode ) c;
			if ( dot.dereferenceType == DEREF_COMPONENT || dot.dereferenceType == DEREF_IDENTIFIER ) {
				if ( StringHelper.isNotEmpty( propertyPath ) ) {
					return true;
				}
			}
		}
		return false;
	}

	private boolean isDotNode(AST n) {
		return n != null && n.getType() == SqlTokenTypes.DOT;
	}

	private void dereferenceEntityJoin(String classAlias, EntityType propertyType, boolean impliedJoin, AST parent) 
	throws SemanticException {
		dereferenceType = DEREF_ENTITY;
		if ( log.isDebugEnabled() ) {
			log.debug( "dereferenceEntityJoin() : generating join for " + propertyName + " in "
					+ getFromElement().getClassName() + " "
					+ ( ( classAlias == null ) ? "{no alias}" : "(" + classAlias + ")" )
					+ " parent = " + ASTUtil.getDebugString( parent )
			);
		}
		// Create a new FROM node for the referenced class.
		String associatedEntityName = propertyType.getAssociatedEntityName();
		String tableAlias = getAliasGenerator().createName( associatedEntityName );

		String[] joinColumns = getColumns();
		String joinPath = getPath();

		if ( impliedJoin && getWalker().isInFrom() ) {
			int impliedJoinType = getWalker().getImpliedJoinType();
			joinType = impliedJoinType;
		}

		FromClause currentFromClause = getWalker().getCurrentFromClause();
		FromElement elem = null;
		elem = currentFromClause.findJoinByPath( joinPath );

///////////////////////////////////////////////////////////////////////////////
//
// This is the piece which recognizes the condition where an implicit join path
// resolved earlier in a correlated subquery is now being referenced in the
// outer query.  For 3.0final, we just let this generate a second join (which
// is exactly how the old parser handles this).  Eventually we need to add this
// logic back in and complete the logic in FromClause.promoteJoin; however,
// FromClause.promoteJoin has its own difficulties (see the comments in
// FromClause.promoteJoin).
//
//		if ( elem == null ) {
//			// see if this joinPath has been used in a "child" FromClause, and if so
//			// promote that element to the outer query
//			FromClause currentNodeOwner = getFromElement().getFromClause();
//			FromClause currentJoinOwner = currentNodeOwner.locateChildFromClauseWithJoinByPath( joinPath );
//			if ( currentJoinOwner != null && currentNodeOwner != currentJoinOwner ) {
//				elem = currentJoinOwner.findJoinByPathLocal( joinPath );
//				if ( elem != null ) {
//					currentFromClause.promoteJoin( elem );
//					// EARLY EXIT!!!
//					return;
//				}
//			}
//		}
//
///////////////////////////////////////////////////////////////////////////////

		if ( elem == null ) {
			// If this is an implied join in a from element, then use the impled join type which is part of the
			// tree parser's state (set by the gramamar actions).
			JoinSequence joinSequence = getSessionFactoryHelper()
				.createJoinSequence( impliedJoin, propertyType, tableAlias, joinType, joinColumns );

			FromElementFactory factory = new FromElementFactory(
			        currentFromClause,
					getLhs().getFromElement(),
					joinPath, 
					classAlias, 
					joinColumns, 
					impliedJoin );
			elem = factory.createEntityJoin( 
					associatedEntityName, 
					tableAlias, 
					joinSequence, 
					fetch, 
					getWalker().isInFrom(), 
					propertyType
			);
		}
		else {
			currentFromClause.addDuplicateAlias(classAlias, elem);
		}
		setImpliedJoin( elem );
		getWalker().addQuerySpaces( elem.getEntityPersister().getQuerySpaces() );
		setFromElement( elem );	// This 'dot' expression now refers to the resulting from element.
	}

	private void setImpliedJoin(FromElement elem) {
		this.impliedJoin = elem;
		if ( getFirstChild().getType() == SqlTokenTypes.DOT ) {
			DotNode dotLhs = ( DotNode ) getFirstChild();
			if ( dotLhs.getImpliedJoin() != null ) {
				this.impliedJoin = dotLhs.getImpliedJoin();
			}
		}
	}

	FromElement getImpliedJoin() {
		return impliedJoin;
	}

	private boolean isPrimaryKeyReference(String property, EntityType propertyType) {
		boolean isIdShortcut = EntityPersister.ENTITY_ID.equals( property ) &&
				propertyType.isReferenceToPrimaryKey();
		return isIdShortcut;
	}

	private boolean isNamedIdPropertyShortcut(EntityType propertyType, String property) {
		final String idPropertyName = getSessionFactoryHelper()
				.getIdentifierOrUniqueKeyPropertyName( propertyType );
		boolean isNamedIdPropertyShortcut = idPropertyName != null && 
				idPropertyName.equals( property );
		return isNamedIdPropertyShortcut;
	}

	private void checkForCorrelatedSubquery(String methodName) {
		if ( isCorrelatedSubselect() ) {
			if ( log.isDebugEnabled() ) {
				log.debug( methodName + "() : correlated subquery" );
			}
		}
	}

	private boolean isCorrelatedSubselect() {
		return getWalker().isSubQuery() && 
			getFromElement().getFromClause() != getWalker().getCurrentFromClause();
	}

	private void dereferenceComponent(AST parent) {
		dereferenceType = DEREF_COMPONENT;
		setPropertyNameAndPath( parent );
	}

	private void dereferenceEntityIdentifier(String propertyName, DotNode dotParent) {
		// special shortcut for id properties, skip the join!
		// this must only occur at the _end_ of a path expression
		if ( log.isDebugEnabled() ) {
			log.debug( "dereferenceShortcut() : property " + 
				propertyName + " in " + getFromElement().getClassName() + 
				" does not require a join." );
		}

		initText();
		setPropertyNameAndPath( dotParent ); // Set the unresolved path in this node and the parent.
		// Set the text for the parent.
		if ( dotParent != null ) {
			dotParent.dereferenceType = DEREF_IDENTIFIER;
			dotParent.setText( getText() );
			dotParent.columns = getColumns();
		}
	}

	private void setPropertyNameAndPath(AST parent) {
		if ( isDotNode( parent ) ) {
			DotNode dotNode = ( DotNode ) parent;
			AST lhs = dotNode.getFirstChild();
			AST rhs = lhs.getNextSibling();
			propertyName = rhs.getText();
			propertyPath = propertyPath + "." + propertyName; // Append the new property name onto the unresolved path.
			dotNode.propertyPath = propertyPath;
			if ( log.isDebugEnabled() ) {
				log.debug( "Unresolved property path is now '" + dotNode.propertyPath + "'" );
			}
		}
		else {
			// Handle "select foo.component from Foo foo", or even "where foo.component = bar.component"
			AST lhs = getFirstChild();
			AST rhs = lhs.getNextSibling();
			propertyPath = rhs.getText();
		}
	}

	public Type getDataType() {
		if ( super.getDataType() == null ) {
			FromElement fromElement = getLhs().getFromElement();
			if ( fromElement == null ) {
				return null;
			}
			// If the lhs is a collection, use CollectionPropertyMapping
			Type propertyType = fromElement.getPropertyType( propertyName, propertyPath );
			if ( log.isDebugEnabled() ) {
				log.debug( "getDataType() : " + propertyPath + " -> " + propertyType );
			}
			super.setDataType( propertyType );
		}
		return super.getDataType();
	}

	void setPropertyPath(String propertyPath) {
		this.propertyPath = propertyPath;
	}

	FromReferenceNode getLhs() {
		FromReferenceNode lhs = ( ( FromReferenceNode ) getFirstChild() );
		if ( lhs == null ) {
			throw new IllegalStateException( "DOT node with no left-hand-side!" );
		}
		return lhs;
	}

	/**
	 * Returns the full path of the node.
	 *
	 * @return the full path of the node.
	 */
	public String getPath() {
		if ( path == null ) {
			FromReferenceNode lhs = getLhs();
			if ( lhs == null ) {
				path = getText();
			}
			else {
				SqlNode rhs = ( SqlNode ) lhs.getNextSibling();
				path = lhs.getPath() + "." + rhs.getOriginalText();
			}
		}
		return path;
	}

	public void setFetch(boolean fetch) {
		this.fetch = fetch;
	}

	public void setScalarColumnText(int i) throws SemanticException {
		String[] sqlColumns = getColumns();
		ColumnHelper.generateScalarColumns( this, sqlColumns, i );
	}

	/**
	 * Special method to resolve expressions in the SELECT list.
	 *
	 * @param useThetaStyleImplicitJoins True for classic-style theta joins.
	 * @throws SemanticException if this cannot be resolved.
	 */
	public void resolveSelectExpression(boolean useThetaStyleImplicitJoins) throws SemanticException {
		if ( getWalker().isShallowQuery() || getWalker().getCurrentFromClause().isSubQuery() ) {
			resolve(false, true);
		}
		else {
			resolve(true, false);
			Type type = getDataType();
			if ( type.isEntityType() ) {
				FromElement fromElement = getFromElement();
				fromElement.setIncludeSubclasses( true ); // Tell the destination fromElement to 'includeSubclasses'.
				if ( useThetaStyleImplicitJoins ) {
					fromElement.getJoinSequence().setUseThetaStyle( true );	// Use theta style (for regression)
					// Move the node up, after the origin node.
					FromElement origin = fromElement.getOrigin();
					if ( origin != null ) {
						ASTUtil.makeSiblingOfParent( origin, fromElement );
					}
				}
			}
		}
	}

	public void setResolvedConstant(String text) {
		path = text;
		dereferenceType = DEREF_JAVA_CONSTANT;
		setResolved(); // Don't resolve the node again.
	}
}