org.eclipse.persistence.internal.jpa.parsing.NotEqualsNode Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of eclipselink Show documentation

EclipseLink build based upon Git transaction f2b9fc5

There is a newer version: 5.0.0-B03

/*
 * Copyright (c) 1998, 2019 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0,
 * or the Eclipse Distribution License v. 1.0 which is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
 */

// Contributors:
//     Oracle - initial API and implementation from Oracle TopLink
package org.eclipse.persistence.internal.jpa.parsing;

import org.eclipse.persistence.expressions.Expression;

/**
 * INTERNAL
 * Purpose: Represent a '<>' in EJBQL
 * 
Responsibilities:
 * 

 *  Generate the correct expression for an '<>' in EJBQL
 * 
 *    @author Jon Driscoll and Joel Lucuik
 *    @since TopLink 4.0
 */
public class NotEqualsNode extends BinaryOperatorNode {

    /**
     * EqualsNode constructor comment.
     */
    public NotEqualsNode() {
        super();
    }

    /**
     * INTERNAL
     * Validate node and calculates its type.
     */
    @Override
    public void validate(ParseTreeContext context) {
        super.validate(context);
        TypeHelper typeHelper = context.getTypeHelper();
        setType(typeHelper.getBooleanType());
    }

    /**
     * Resolve the expression. The steps are:
     * 1. Set the expressionBuilder for the left and right nodes
     * 2. Generate the expression for the left node
     * 3. Add the .notEqual to the where clause returned from step 2
     * 4. Generate the expression for the right side and use it as the parameter for the .equals()
     * 5. Return the completed where clause to the caller
     */
    @Override
    public Expression generateExpression(GenerationContext context) {
        Expression whereClause = getLeft().generateExpression(context);
        whereClause = whereClause.notEqual(getRight().generateExpression(context));
        return whereClause;
    }

    /**
     * INTERNAL
     * Get the string representation of this node.
     */
    @Override
    public String getAsString() {
        return left.getAsString() + " <> " + right.getAsString();
    }
}