org.objectstyle.cayenne.exp.BinaryExpression Maven / Gradle / Ivy

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/* ====================================================================
 * 
 * The ObjectStyle Group Software License, version 1.1
 * ObjectStyle Group - http://objectstyle.org/
 * 
 * Copyright (c) 2002-2005, Andrei (Andrus) Adamchik and individual authors
 * of the software. All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 
 * 3. The end-user documentation included with the redistribution, if any,
 *    must include the following acknowlegement:
 *    "This product includes software developed by independent contributors
 *    and hosted on ObjectStyle Group web site (http://objectstyle.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 * 
 * 4. The names "ObjectStyle Group" and "Cayenne" must not be used to endorse
 *    or promote products derived from this software without prior written
 *    permission. For written permission, email
 *    "andrus at objectstyle dot org".
 * 
 * 5. Products derived from this software may not be called "ObjectStyle"
 *    or "Cayenne", nor may "ObjectStyle" or "Cayenne" appear in their
 *    names without prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE OBJECTSTYLE GROUP OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 * 
 * This software consists of voluntary contributions made by many
 * individuals and hosted on ObjectStyle Group web site.  For more
 * information on the ObjectStyle Group, please see
 * .
 */
package org.objectstyle.cayenne.exp;

import java.io.PrintWriter;

/**
 * Generic binary expression. Describes an expression in a form: "leftoperand operation rightoperand".
 * SQL has a lot of binary expressions, for example AND, OR, =, etc.
 * 
 * @deprecated since 1.2
 * @author Andrus Adamchik
 */
public class BinaryExpression extends Expression {

    protected Object leftOperand;
    protected Object rightOperand;

    public BinaryExpression() {
    }

    public BinaryExpression(int type) {
        this.type = type;
    }

    protected void flattenTree() {

    }

    protected boolean pruneNodeForPrunedChild(Object prunedChild) {
        return true;
    }

    public final int getOperandCount() {
        return 2;
    }

    public Object evaluate(Object o) {
        return ASTCompiler.compile(this).evaluateASTChain(o);
    }

    /**
     * Creates a copy of this expression node, without copying children.
     * 
     * @since 1.1
     */
    public Expression shallowCopy() {
        return new BinaryExpression(type);
    }

    public Expression notExp() {
        Expression exp = ExpressionFactory.expressionOfType(Expression.NOT);
        exp.setOperand(0, this);
        return exp;
    }

    public Object getOperand(int index) {
        if (index == 0)
            return leftOperand;
        else if (index == 1)
            return rightOperand;

        throw new IllegalArgumentException("Invalid operand index for BinaryExpression: "
                + index);
    }

    public void setOperand(int index, Object value) {
        if (index == 0) {
            leftOperand = value;
            return;
        }
        else if (index == 1) {
            rightOperand = value;
            return;
        }

        throw new IllegalArgumentException("Invalid operand index for BinaryExpression: "
                + index);
    }

    /**
     * @since 1.1
     */
    public void encodeAsString(PrintWriter pw) {
        for (int i = 0; i < getOperandCount(); i++) {
            if (i > 0 || getOperandCount() == 1) {
                pw.print(" ");
                pw.print(expName());
                pw.print(" ");
            }

            Object op = getOperand(i);
            if (op == null) {
                pw.print("");
            }
            else if (op instanceof String) {
                pw.print("'" + op + "'");
            }
            else if (op instanceof Expression) {
                pw.print('(');
                ((Expression) op).encodeAsString(pw);
                pw.print(')');
            }
            else {
                pw.print(String.valueOf(op));
            }
        }
    }
}