1 /* 2 * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/expr/DefaultUnionExpr.java,v 1.14 2005/09/06 13:41:01 elharo Exp $ 3 * $Revision: 1.14 $ 4 * $Date: 2005/09/06 13:41:01 $ 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: DefaultUnionExpr.java,v 1.14 2005/09/06 13:41:01 elharo Exp $ 60 */ 61 62 63 64 package org.jaxen.expr; 65 66 import java.util.ArrayList; 67 import java.util.Collections; 68 import java.util.HashSet; 69 import java.util.Iterator; 70 import java.util.List; 71 import java.util.Set; 72 import org.jaxen.Context; 73 import org.jaxen.JaxenException; 74 import org.jaxen.XPathSyntaxException; 75 76 /*** 77 * @deprecated this class will become non-public in the future; 78 * use the interface instead 79 */ 80 public class DefaultUnionExpr extends DefaultBinaryExpr implements UnionExpr 81 { 82 public DefaultUnionExpr(Expr lhs, 83 Expr rhs) 84 { 85 super( lhs, 86 rhs ); 87 } 88 89 public String getOperator() 90 { 91 return "|"; 92 } 93 94 public String toString() 95 { 96 return "[(DefaultUnionExpr): " + getLHS() + ", " + getRHS() + "]"; 97 } 98 99 public Object evaluate(Context context) throws JaxenException 100 { 101 List results = new ArrayList(); 102 103 try { 104 List lhsResults = (List) getLHS().evaluate( context ); 105 List rhsResults = (List) getRHS().evaluate( context ); 106 107 Set unique = new HashSet(); 108 109 results.addAll( lhsResults ); 110 unique.addAll( lhsResults ); 111 112 Iterator rhsIter = rhsResults.iterator(); 113 114 while ( rhsIter.hasNext() ) 115 { 116 Object each = rhsIter.next(); 117 118 if ( ! unique.contains( each ) ) 119 { 120 results.add( each ); 121 unique.add( each ); 122 } 123 } 124 125 Collections.sort(results, new NodeComparator(context.getNavigator())); 126 127 return results; 128 } 129 catch (ClassCastException e) { 130 throw new XPathSyntaxException(this.getText(), context.getPosition(), "Unions are only allowed over node-sets"); 131 } 132 } 133 134 public void accept(Visitor visitor) 135 { 136 visitor.visit(this); 137 } 138 139 } 140