1 /* 2 * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/expr/DefaultAndExpr.java,v 1.16 2006/11/30 18:49:27 elharo Exp $ 3 * $Revision: 1.16 $ 4 * $Date: 2006/11/30 18:49:27 $ 5 * 6 * ==================================================================== 7 * 8 * Copyright 2000-2002 bob mcwhirter & James Strachan. 9 * All rights reserved. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions are 13 * met: 14 * 15 * * Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 18 * * Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 22 * * Neither the name of the Jaxen Project nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS 27 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A 29 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER 30 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 31 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 32 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 33 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 34 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 35 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 36 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 37 * 38 * ==================================================================== 39 * This software consists of voluntary contributions made by many 40 * individuals on behalf of the Jaxen Project and was originally 41 * created by bob mcwhirter <bob@werken.com> and 42 * James Strachan <jstrachan@apache.org>. For more information on the 43 * Jaxen Project, please see <http://www.jaxen.org/>. 44 * 45 * $Id: DefaultAndExpr.java,v 1.16 2006/11/30 18:49:27 elharo Exp $ 46 */ 47 48 package org.jaxen.expr; 49 50 import org.jaxen.Context; 51 import org.jaxen.JaxenException; 52 import org.jaxen.Navigator; 53 import org.jaxen.function.BooleanFunction; 54 55 class DefaultAndExpr extends DefaultLogicalExpr 56 { 57 /*** 58 * 59 */ 60 private static final long serialVersionUID = -5237984010263103742L; 61 62 DefaultAndExpr(Expr lhs, 63 Expr rhs) 64 { 65 super( lhs, 66 rhs ); 67 } 68 69 public String getOperator() 70 { 71 return "and"; 72 } 73 74 public String toString() 75 { 76 return "[(DefaultAndExpr): " + getLHS() + ", " + getRHS() + "]"; 77 } 78 79 public Object evaluate(Context context) throws JaxenException 80 { 81 Navigator nav = context.getNavigator(); 82 Boolean lhsValue = BooleanFunction.evaluate( getLHS().evaluate( context ), nav ); 83 84 if ( !lhsValue.booleanValue() ) 85 { 86 return Boolean.FALSE; 87 } 88 89 // Short circuits are required in XPath. "The right operand is not 90 // evaluated if the left operand evaluates to false." 91 Boolean rhsValue = BooleanFunction.evaluate( getRHS().evaluate( context ), nav ); 92 93 if ( !rhsValue.booleanValue() ) 94 { 95 return Boolean.FALSE; 96 } 97 98 return Boolean.TRUE; 99 } 100 101 102 }