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: And.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 'and' operation expression executer.
029     */
030    public class And extends Operation
031    {
032        static final long serialVersionUID = 392330077126534022L;
033    
034      /**
035       * AND two expressions and return the boolean result. Override
036       * superclass method for optimization purposes.
037       *
038       * @param xctxt The runtime execution context.
039       *
040       * @return {@link org.apache.xpath.objects.XBoolean#S_TRUE} or 
041       * {@link org.apache.xpath.objects.XBoolean#S_FALSE}.
042       *
043       * @throws javax.xml.transform.TransformerException
044       */
045      public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException
046      {
047    
048        XObject expr1 = m_left.execute(xctxt);
049    
050        if (expr1.bool())
051        {
052          XObject expr2 = m_right.execute(xctxt);
053    
054          return expr2.bool() ? XBoolean.S_TRUE : XBoolean.S_FALSE;
055        }
056        else
057          return XBoolean.S_FALSE;
058      }
059      
060      /**
061       * Evaluate this operation directly to a boolean.
062       *
063       * @param xctxt The runtime execution context.
064       *
065       * @return The result of the operation as a boolean.
066       *
067       * @throws javax.xml.transform.TransformerException
068       */
069      public boolean bool(XPathContext xctxt)
070              throws javax.xml.transform.TransformerException
071      {
072        return (m_left.bool(xctxt) && m_right.bool(xctxt));
073      }
074    
075    }