1 /* 2 * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/expr/DefaultEqualityExpr.java,v 1.11 2005/03/21 22:39:16 elharo Exp $ 3 * $Revision: 1.11 $ 4 * $Date: 2005/03/21 22:39:16 $ 5 * 6 * ==================================================================== 7 * 8 * Copyright (C) 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 13 * are met: 14 * 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions, and the following disclaimer. 17 * 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions, and the disclaimer that follows 20 * these conditions in the documentation and/or other materials 21 * provided with the distribution. 22 * 23 * 3. The name "Jaxen" must not be used to endorse or promote products 24 * derived from this software without prior written permission. For 25 * written permission, please contact license@jaxen.org. 26 * 27 * 4. Products derived from this software may not be called "Jaxen", nor 28 * may "Jaxen" appear in their name, without prior written permission 29 * from the Jaxen Project Management (pm@jaxen.org). 30 * 31 * In addition, we request (but do not require) that you include in the 32 * end-user documentation provided with the redistribution and/or in the 33 * software itself an acknowledgement equivalent to the following: 34 * "This product includes software developed by the 35 * Jaxen Project (http://www.jaxen.org/)." 36 * Alternatively, the acknowledgment may be graphical using the logos 37 * available at http://www.jaxen.org/ 38 * 39 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED 40 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 41 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 42 * DISCLAIMED. IN NO EVENT SHALL THE Jaxen AUTHORS OR THE PROJECT 43 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 45 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF 46 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 47 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 48 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 49 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 50 * SUCH DAMAGE. 51 * 52 * ==================================================================== 53 * This software consists of voluntary contributions made by many 54 * individuals on behalf of the Jaxen Project and was originally 55 * created by bob mcwhirter <bob@werken.com> and 56 * James Strachan <jstrachan@apache.org>. For more information on the 57 * Jaxen Project, please see <http://www.jaxen.org/>. 58 * 59 * $Id: DefaultEqualityExpr.java,v 1.11 2005/03/21 22:39:16 elharo Exp $ 60 */ 61 62 63 64 package org.jaxen.expr; 65 66 import java.util.Iterator; 67 import java.util.List; 68 import org.jaxen.Context; 69 import org.jaxen.JaxenException; 70 import org.jaxen.Navigator; 71 import org.jaxen.function.BooleanFunction; 72 import org.jaxen.function.NumberFunction; 73 import org.jaxen.function.StringFunction; 74 75 abstract class DefaultEqualityExpr extends DefaultTruthExpr implements EqualityExpr 76 { 77 public DefaultEqualityExpr( Expr lhs, Expr rhs ) 78 { 79 super( lhs, rhs ); 80 } 81 82 public String toString() 83 { 84 return "[(DefaultEqualityExpr): " + getLHS() + ", " + getRHS() + "]"; 85 } 86 87 public Object evaluate( Context context ) throws JaxenException 88 { 89 Object lhsValue = getLHS().evaluate( context ); 90 Object rhsValue = getRHS().evaluate( context ); 91 92 if( lhsValue == null || rhsValue == null ) 93 { 94 return Boolean.FALSE; 95 } 96 97 Navigator nav = context.getNavigator(); 98 99 if( bothAreSets( lhsValue, rhsValue ) ) 100 { 101 return evaluateSetSet( (List) lhsValue, (List) rhsValue, nav ); 102 } 103 else if ( eitherIsSet( lhsValue, rhsValue ) ) 104 { 105 if ( isSet( lhsValue ) ) 106 { 107 return evaluateSetSet( (List) lhsValue, convertToList( rhsValue ), nav ); 108 } 109 else 110 { 111 return evaluateSetSet( convertToList( lhsValue ), (List) rhsValue, nav ); 112 } 113 } 114 else 115 { 116 return evaluateObjectObject( lhsValue, rhsValue, nav ) ? Boolean.TRUE : Boolean.FALSE; 117 } 118 } 119 120 private Boolean evaluateSetSet( List lhsSet, List rhsSet, Navigator nav ) 121 { 122 if( setIsEmpty( lhsSet ) || setIsEmpty( rhsSet ) ) 123 { 124 return Boolean.FALSE; 125 } 126 127 for( Iterator lhsIterator = lhsSet.iterator(); lhsIterator.hasNext(); ) 128 { 129 Object lhs = lhsIterator.next(); 130 131 for( Iterator rhsIterator = rhsSet.iterator(); rhsIterator.hasNext(); ) 132 { 133 Object rhs = rhsIterator.next(); 134 135 if( evaluateObjectObject( lhs, rhs, nav ) ) 136 { 137 return Boolean.TRUE; 138 } 139 } 140 } 141 142 return Boolean.FALSE; 143 } 144 145 private boolean evaluateObjectObject( Object lhs, Object rhs, Navigator nav ) 146 { 147 if( eitherIsBoolean( lhs, rhs ) ) 148 { 149 return evaluateObjectObject( BooleanFunction.evaluate( lhs, nav ), 150 BooleanFunction.evaluate( rhs, nav ) ); 151 } 152 else if( eitherIsNumber( lhs, rhs ) ) 153 { 154 return evaluateObjectObject( NumberFunction.evaluate( lhs, 155 nav ), 156 NumberFunction.evaluate( rhs, 157 nav ) ); 158 } 159 else 160 { 161 return evaluateObjectObject( StringFunction.evaluate( lhs, 162 nav ), 163 StringFunction.evaluate( rhs, 164 nav ) ); 165 } 166 } 167 168 protected abstract boolean evaluateObjectObject( Object lhs, Object rhs ); 169 }