001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one
003     * or more contributor license agreements. See the NOTICE file
004     * distributed with this work for additional information
005     * regarding copyright ownership. The ASF licenses this file
006     * to you under the Apache License, Version 2.0 (the  "License");
007     * you may not use this file except in compliance with the License.
008     * You may obtain a copy of the License at
009     *
010     *     http://www.apache.org/licenses/LICENSE-2.0
011     *
012     * Unless required by applicable law or agreed to in writing, software
013     * distributed under the License is distributed on an "AS IS" BASIS,
014     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015     * See the License for the specific language governing permissions and
016     * limitations under the License.
017     */
018    /*
019     * $Id: Equals.java 468655 2006-10-28 07:12:06Z minchau $
020     */
021    package org.apache.xpath.operations;
022    
023    import org.apache.xpath.XPathContext;
024    import org.apache.xpath.objects.XBoolean;
025    import org.apache.xpath.objects.XObject;
026    
027    /**
028     * The '=' operation expression executer.
029     */
030    public class Equals extends Operation
031    {
032        static final long serialVersionUID = -2658315633903426134L;
033    
034      /**
035       * Apply the operation to two operands, and return the result.
036       *
037       *
038       * @param left non-null reference to the evaluated left operand.
039       * @param right non-null reference to the evaluated right operand.
040       *
041       * @return non-null reference to the XObject that represents the result of the operation.
042       *
043       * @throws javax.xml.transform.TransformerException
044       */
045      public XObject operate(XObject left, XObject right)
046              throws javax.xml.transform.TransformerException
047      {
048        return left.equals(right) ? XBoolean.S_TRUE : XBoolean.S_FALSE;
049      }
050      
051      /**
052       * Execute a binary operation by calling execute on each of the operands,
053       * and then calling the operate method on the derived class.
054       *
055       *
056       * @param xctxt The runtime execution context.
057       *
058       * @return The XObject result of the operation.
059       *
060       * @throws javax.xml.transform.TransformerException
061       */
062      public boolean bool(XPathContext xctxt)
063              throws javax.xml.transform.TransformerException
064      {
065        XObject left = m_left.execute(xctxt, true);
066        XObject right = m_right.execute(xctxt, true);
067    
068        boolean result = left.equals(right) ? true : false;
069            left.detach();
070            right.detach();
071        return result;
072      }
073    
074    }