1 /*
2 * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/function/TranslateFunction.java,v 1.4 2003/06/29 18:04:41 ssanders Exp $
3 * $Revision: 1.4 $
4 * $Date: 2003/06/29 18:04:41 $
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: TranslateFunction.java,v 1.4 2003/06/29 18:04:41 ssanders Exp $
60 */
61
62
63 package org.jaxen.function;
64
65 import java.util.HashMap;
66 import java.util.List;
67 import java.util.Map;
68
69 import org.jaxen.Context;
70 import org.jaxen.Function;
71 import org.jaxen.FunctionCallException;
72 import org.jaxen.Navigator;
73
74 /***
75 * <p><b>4.2</b> <code><i>string</i> translate(<i>string</i>,<i>string</i>,<i>string</i>)</code>
76 *
77 * The translation is done thru a HashMap.
78 * Performance tip (for anyone who needs to improve the performance of this particular function):
79 * Cache the HashMaps, once they are constructed.
80 *
81 * @author Jan Dvorak ( jan.dvorak @ mathan.cz )
82 *
83 */
84 public class TranslateFunction implements Function
85 {
86
87 public Object call(Context context,
88 List args) throws FunctionCallException
89 {
90 if (args.size() == 3)
91 {
92 return evaluate( args.get(0),
93 args.get(1),
94 args.get(2),
95 context.getNavigator() );
96 }
97
98 throw new FunctionCallException( "translate() requires three arguments." );
99 }
100
101 public static String evaluate(Object strArg,
102 Object fromArg,
103 Object toArg,
104 Navigator nav)
105 {
106 String inStr = StringFunction.evaluate( strArg, nav );
107 String fromStr = StringFunction.evaluate( fromArg, nav );
108 String toStr = StringFunction.evaluate( toArg, nav );
109
110 // Initialize the mapping in a HashMap
111 Map charMap = new HashMap();
112 int fromLen = fromStr.length();
113 int toLen = toStr.length();
114 for ( int i = 0; i < fromLen; ++i ) {
115 String cFrom = fromStr.substring( i, i+1 ).intern();
116 if ( charMap.containsKey( cFrom ) ) {
117 // We've seen the character before, ignore
118 continue;
119 }
120 if ( i < toLen ) {
121 Character cTo = new Character( toStr.charAt( i ) );
122 // Will change
123 charMap.put( cFrom, cTo );
124 } else {
125 // Will delete
126 charMap.put( cFrom, null );
127 }
128 }
129
130 // Process the input string thru the map
131 StringBuffer outStr = new StringBuffer( inStr.length() );
132 int inLen = inStr.length();
133 for ( int i = 0; i < inLen; ++i ) {
134 String cIn = inStr.substring( i, i+1 );
135 if ( charMap.containsKey( cIn ) ) {
136 Character cTo = (Character) charMap.get( cIn );
137 if ( cTo != null ) {
138 outStr.append( cTo.charValue() );
139 }
140 } else {
141 outStr.append( cIn );
142 }
143 }
144
145 return new String( outStr );
146 }
147 }
148