hqlsqlwalker.java

一个Java持久层类库

			insertStatement.getIntoClause().prependVersionColumnSpec();
		}

		if ( insertStatement.getIntoClause().isDiscriminated() ) {
			String sqlValue = insertStatement.getIntoClause().getQueryable().getDiscriminatorSQLValue();
			AST discrimValue = getASTFactory().create( HqlSqlTokenTypes.SQL_TOKEN, sqlValue );
			insertStatement.getSelectClause().addChild( discrimValue );
		}

	}

	private boolean isDatabaseGeneratedTimestamp(Type type) {
		// currently only the Hibernate-supplied DbTimestampType is supported here
		return DbTimestampType.class.isAssignableFrom( type.getClass() );
	}

	private boolean isIntegral(Type type) {
		return Long.class.isAssignableFrom( type.getReturnedClass() )
		       || Integer.class.isAssignableFrom( type.getReturnedClass() )
		       || long.class.isAssignableFrom( type.getReturnedClass() )
		       || int.class.isAssignableFrom( type.getReturnedClass() );
	}

	private void useSelectClause(AST select) throws SemanticException {
		selectClause = ( SelectClause ) select;
		selectClause.initializeExplicitSelectClause( currentFromClause );
	}

	private void createSelectClauseFromFromClause(QueryNode qn) throws SemanticException {
		AST select = astFactory.create( SELECT_CLAUSE, "{derived select clause}" );
		AST sibling = qn.getFromClause();
		qn.setFirstChild( select );
		select.setNextSibling( sibling );
		selectClause = ( SelectClause ) select;
		selectClause.initializeDerivedSelectClause( currentFromClause );
		if ( log.isDebugEnabled() ) {
			log.debug( "Derived SELECT clause created." );
		}
	}

	protected void resolve(AST node) throws SemanticException {
		if ( node != null ) {
			// This is called when it's time to fully resolve a path expression.
			ResolvableNode r = ( ResolvableNode ) node;
			if ( isInFunctionCall() ) {
				r.resolveInFunctionCall( false, true );
			}
			else {
				r.resolve( false, true );	// Generate implicit joins, only if necessary.
			}
		}
	}

	protected void resolveSelectExpression(AST node) throws SemanticException {
		// This is called when it's time to fully resolve a path expression.
		int type = node.getType();
		switch ( type ) {
			case DOT:
				DotNode dot = ( DotNode ) node;
				dot.resolveSelectExpression();
				break;
			case ALIAS_REF:
				// Notify the FROM element that it is being referenced by the select.
				FromReferenceNode aliasRefNode = ( FromReferenceNode ) node;
				//aliasRefNode.resolve( false, false, aliasRefNode.getText() ); //TODO: is it kosher to do it here?
				aliasRefNode.resolve( false, false ); //TODO: is it kosher to do it here?
				FromElement fromElement = aliasRefNode.getFromElement();
				if ( fromElement != null ) {
					fromElement.setIncludeSubclasses( true );
				}
			default:
				break;
		}
	}

	protected void beforeSelectClause() throws SemanticException {
		// Turn off includeSubclasses on all FromElements.
		FromClause from = getCurrentFromClause();
		List fromElements = from.getFromElements();
		for ( Iterator iterator = fromElements.iterator(); iterator.hasNext(); ) {
			FromElement fromElement = ( FromElement ) iterator.next();
			fromElement.setIncludeSubclasses( false );
		}
	}

	protected AST generatePositionalParameter(AST inputNode) throws SemanticException {
		if ( namedParameters.size() > 0 ) {
			throw new SemanticException( "cannot define positional parameter after any named parameters have been defined" );
		}
		ParameterNode parameter = ( ParameterNode ) astFactory.create( PARAM, "?" );
		PositionalParameterSpecification paramSpec = new PositionalParameterSpecification(
				( ( Node ) inputNode ).getLine(),
		        ( ( Node ) inputNode ).getColumn(),
				positionalParameterCount++
		);
		parameter.setHqlParameterSpecification( paramSpec );
		parameters.add( paramSpec );
		return parameter;
	}

	protected AST generateNamedParameter(AST delimiterNode, AST nameNode) throws SemanticException {
		String name = nameNode.getText();
		trackNamedParameterPositions( name );

		// create the node initially with the param name so that it shows
		// appropriately in the "original text" attribute
		ParameterNode parameter = ( ParameterNode ) astFactory.create( NAMED_PARAM, name );
		parameter.setText( "?" );

		NamedParameterSpecification paramSpec = new NamedParameterSpecification(
				( ( Node ) delimiterNode ).getLine(),
		        ( ( Node ) delimiterNode ).getColumn(),
				name
		);
		parameter.setHqlParameterSpecification( paramSpec );
		parameters.add( paramSpec );
		return parameter;
	}

	private void trackNamedParameterPositions(String name) {
		Integer loc = new Integer( parameterCount++ );
		Object o = namedParameters.get( name );
		if ( o == null ) {
			namedParameters.put( name, loc );
		}
		else if ( o instanceof Integer ) {
			ArrayList list = new ArrayList( 4 );
			list.add( o );
			list.add( loc );
			namedParameters.put( name, list );
		}
		else {
			( ( ArrayList ) o ).add( loc );
		}
	}

	protected void processConstant(AST constant) throws SemanticException {
		literalProcessor.processConstant( constant, true );  // Use the delegate, resolve identifiers as FROM element aliases.
	}

	protected void processBoolean(AST constant) throws SemanticException {
		literalProcessor.processBoolean( constant );  // Use the delegate.
	}

	protected void processNumericLiteral(AST literal) {
		literalProcessor.processNumeric( literal );
	}

	protected void processIndex(AST indexOp) throws SemanticException {
		IndexNode indexNode = ( IndexNode ) indexOp;
		indexNode.resolve( true, true );
	}

	protected void processFunction(AST functionCall, boolean inSelect) throws SemanticException {
		MethodNode methodNode = ( MethodNode ) functionCall;
		methodNode.resolve( inSelect );
	}

	protected void processConstructor(AST constructor) throws SemanticException {
		ConstructorNode constructorNode = ( ConstructorNode ) constructor;
		constructorNode.prepare();
	}

    protected void setAlias(AST selectExpr, AST ident) {
        ((SelectExpression) selectExpr).setAlias(ident.getText());
    }

	/**
	 * Returns the locations of all occurrences of the named parameter.
	 */
	public int[] getNamedParameterLocations(String name) throws QueryException {
		Object o = namedParameters.get( name );
		if ( o == null ) {
			QueryException qe = new QueryException( QueryTranslator.ERROR_NAMED_PARAMETER_DOES_NOT_APPEAR + name );
			qe.setQueryString( queryTranslatorImpl.getQueryString() );
			throw qe;
		}
		if ( o instanceof Integer ) {
			return new int[]{( ( Integer ) o ).intValue()};
		}
		else {
			return ArrayHelper.toIntArray( ( ArrayList ) o );
		}
	}

	public void addQuerySpaces(Serializable[] spaces) {
		for ( int i = 0; i < spaces.length; i++ ) {
			querySpaces.add( spaces[i] );
		}
	}

	public Type[] getReturnTypes() {
		return selectClause.getQueryReturnTypes();
	}

	public String[] getReturnAliases() {
		return selectClause.getQueryReturnAliases();
	}

	public SelectClause getSelectClause() {
		return selectClause;
	}
	
	public FromClause getFinalFromClause() {
		FromClause top = currentFromClause;
		while ( top.getParentFromClause() != null ) {
			top = top.getParentFromClause();
		}
		return top;
	}

	public boolean isShallowQuery() {
		// select clauses for insert statements should alwasy be treated as shallow
		return getStatementType() == INSERT || queryTranslatorImpl.isShallowQuery();
	}

	public Map getEnabledFilters() {
		return queryTranslatorImpl.getEnabledFilters();
	}

	public LiteralProcessor getLiteralProcessor() {
		return literalProcessor;
	}

	public ASTPrinter getASTPrinter() {
		return printer;
	}

	public ArrayList getParameters() {
		return parameters;
	}

	public int getNumberOfParametersInSetClause() {
		return numberOfParametersInSetClause;
	}

	protected void evaluateAssignment(AST eq) throws SemanticException {
		prepareLogicOperator( eq );
		Queryable persister = getCurrentFromClause().getFromElement().getQueryable();
		evaluateAssignment( eq, persister, -1 );
	}

	private void evaluateAssignment(AST eq, Queryable persister, int targetIndex) {
		if ( persister.isMultiTable() ) {
			// no need to even collect this information if the persister is considered multi-table
			AssignmentSpecification specification = new AssignmentSpecification( eq, persister );
			if ( targetIndex >= 0 ) {
				assignmentSpecifications.add( targetIndex, specification );
			}
			else {
				assignmentSpecifications.add( specification );
			}
			numberOfParametersInSetClause += specification.getParameters().length;
		}
	}

	public ArrayList getAssignmentSpecifications() {
		return assignmentSpecifications;
	}

	protected AST createIntoClause(String path, AST propertySpec) throws SemanticException {
		Queryable persister = ( Queryable ) getSessionFactoryHelper().requireClassPersister( path );

		IntoClause intoClause = ( IntoClause ) getASTFactory().create( INTO, persister.getEntityName() );
		intoClause.setFirstChild( propertySpec );
		intoClause.initialize( persister );

		addQuerySpaces( persister.getQuerySpaces() );

		return intoClause;
	}

	protected void prepareVersioned(AST updateNode, AST versioned) throws SemanticException {
		UpdateStatement updateStatement = ( UpdateStatement ) updateNode;
		FromClause fromClause = updateStatement.getFromClause();
		if ( versioned != null ) {
			// Make sure that the persister is versioned
			Queryable persister = fromClause.getFromElement().getQueryable();
			if ( !persister.isVersioned() ) {
				throw new SemanticException( "increment option specified for update of non-versioned entity" );
			}

			VersionType versionType = persister.getVersionType();
			if ( versionType instanceof UserVersionType ) {
				throw new SemanticException( "user-defined version types not supported for increment option" );
			}

			AST eq = getASTFactory().create( HqlSqlTokenTypes.EQ, "=" );
			AST versionPropertyNode = generateVersionPropertyNode( persister );

			eq.setFirstChild( versionPropertyNode );

			AST versionIncrementNode = null;
			if ( Date.class.isAssignableFrom( versionType.getReturnedClass() ) ) {
				versionIncrementNode = getASTFactory().create( HqlSqlTokenTypes.PARAM, "?" );
				ParameterSpecification paramSpec = new VersionTypeSeedParameterSpecification( versionType );
				( ( ParameterNode ) versionIncrementNode ).setHqlParameterSpecification( paramSpec );
				parameters.add( 0, paramSpec );
			}
			else {
				// Not possible to simply re-use the versionPropertyNode here as it causes
				// OOM errors due to circularity :(
				versionIncrementNode = getASTFactory().create( HqlSqlTokenTypes.PLUS, "+" );
				versionIncrementNode.setFirstChild( generateVersionPropertyNode( persister ) );
				versionIncrementNode.addChild( getASTFactory().create( HqlSqlTokenTypes.IDENT, "1" ) );
			}

			eq.addChild( versionIncrementNode );

			evaluateAssignment( eq, persister, 0 );

			AST setClause = updateStatement.getSetClause();
			AST currentFirstSetElement = setClause.getFirstChild();
			setClause.setFirstChild( eq );
			eq.setNextSibling( currentFirstSetElement );
		}
	}

	private AST generateVersionPropertyNode(Queryable persister) throws SemanticException {
		String versionPropertyName = persister.getPropertyNames()[ persister.getVersionProperty() ];
		AST versionPropertyRef = getASTFactory().create( HqlSqlTokenTypes.IDENT, versionPropertyName );
		AST versionPropertyNode = lookupNonQualifiedProperty( versionPropertyRef );
		resolve( versionPropertyNode );
		return versionPropertyNode;
	}

	protected void prepareLogicOperator(AST operator) throws SemanticException {
		( ( OperatorNode ) operator ).initialize();
	}

	protected void prepareArithmeticOperator(AST operator) throws SemanticException {
		( ( OperatorNode ) operator ).initialize();
	}

	public static void panic() {
		throw new QueryException( "TreeWalker: panic" );
	}
}