1 /* 2 * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/expr/DefaultUnionExpr.java,v 1.17 2006/11/30 18:49:27 elharo Exp $ 3 * $Revision: 1.17 $ 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: DefaultUnionExpr.java,v 1.17 2006/11/30 18:49:27 elharo Exp $ 46 */ 47 48 49 50 package org.jaxen.expr; 51 52 import java.util.ArrayList; 53 import java.util.Collections; 54 import java.util.HashSet; 55 import java.util.Iterator; 56 import java.util.List; 57 import java.util.Set; 58 import org.jaxen.Context; 59 import org.jaxen.JaxenException; 60 import org.jaxen.XPathSyntaxException; 61 62 /*** 63 * @deprecated this class will become non-public in the future; 64 * use the interface instead 65 */ 66 public class DefaultUnionExpr extends DefaultBinaryExpr implements UnionExpr 67 { 68 /*** 69 * 70 */ 71 private static final long serialVersionUID = 7629142718276852707L; 72 73 public DefaultUnionExpr(Expr lhs, 74 Expr rhs) 75 { 76 super( lhs, 77 rhs ); 78 } 79 80 public String getOperator() 81 { 82 return "|"; 83 } 84 85 public String toString() 86 { 87 return "[(DefaultUnionExpr): " + getLHS() + ", " + getRHS() + "]"; 88 } 89 90 public Object evaluate(Context context) throws JaxenException 91 { 92 List results = new ArrayList(); 93 94 try { 95 List lhsResults = (List) getLHS().evaluate( context ); 96 List rhsResults = (List) getRHS().evaluate( context ); 97 98 Set unique = new HashSet(); 99 100 results.addAll( lhsResults ); 101 unique.addAll( lhsResults ); 102 103 Iterator rhsIter = rhsResults.iterator(); 104 105 while ( rhsIter.hasNext() ) 106 { 107 Object each = rhsIter.next(); 108 109 if ( ! unique.contains( each ) ) 110 { 111 results.add( each ); 112 unique.add( each ); 113 } 114 } 115 116 Collections.sort(results, new NodeComparator(context.getNavigator())); 117 118 return results; 119 } 120 catch (ClassCastException e) { 121 throw new XPathSyntaxException(this.getText(), context.getPosition(), "Unions are only allowed over node-sets"); 122 } 123 } 124 125 } 126