##### Coverage Report - org.jaxen.function.TranslateFunction

Classes in this File | Line Coverage | Branch Coverage | Complexity
TranslateFunction |
96% |
100% |
| 3.8333333333333335;3.833

1 |  |
     /*
2 |  |
      * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/function/TranslateFunction.java,v 1.9 2005/06/28 13:44:45 elharo Exp $
3 |  |
      * $Revision: 1.9 $
4 |  |
      * $Date: 2005/06/28 13:44:45 $
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 1.9 2005/06/28 13:44:45 elharo 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>
76 |  |
      * <b>4.2</b>
77 |  |
      * <code><i>string</i> translate(<i>string</i>,<i>string</i>,<i>string</i>)</code>
78 |  |
      * </p>
79 |  |
      *
80 |  |
      * <blockquote src="http://www.w3.org/TR/xpath#function-translate">
81 |  |
      * <p>
82 |  |
      * The <b><a href="http://www.w3.org/TR/xpath#function-translate">translate</a></b> function
83 |  |
      * returns the first argument string with occurrences of characters in
84 |  |
      * the second argument string replaced by the character at the
85 |  |
      * corresponding position in the third argument string. For example,
86 |  |
      * <code>translate("bar","abc","ABC")</code> returns the string
87 |  |
      * <code>BAr</code>. If there is a character in the second argument
88 |  |
      * string with no character at a corresponding position in the third
89 |  |
      * argument string (because the second argument string is longer than
90 |  |
      * the third argument string), then occurrences of that character in the
91 |  |
      * first argument string are removed. For example,
92 |  |
      * <code>translate("--aaa--","abc-","ABC")</code> returns
93 |  |
      * <code>"AAA"</code>. If a character occurs more than once in the
94 |  |
      * second argument string, then the first occurrence determines the
95 |  |
      * replacement character. If the third argument string is longer than
96 |  |
      * the second argument string, then excess characters are ignored.
97 |  |
      * </p>
98 |  |
      *
99 |  |
      * <blockquote> <b>NOTE: </b>The <b>translate</b> function is not a
100 |  |
      * sufficient solution for case conversion in all languages. A future
101 |  |
      * version of XPath may provide additional functions for case
102 |  |
      * conversion.</blockquote>
103 |  |
      *
104 |  |
      * </blockquote>
105 |  |
      *
106 |  |
      * @author Jan Dvorak ( jan.dvorak @ mathan.cz )
107 |  |
      *
108 |  |
      * @see <a href="http://www.w3.org/TR/xpath#function-translate"
109 |  |
      *      target="_top">Section 4.2 of the XPath Specification</a>
110 |  |
      */
111 |  |
     public class TranslateFunction implements Function
112 |  |
     {
113 |  |
114 |  |
          /* The translation is done thru a HashMap. Performance tip (for anyone
115 |  |
           * who needs to improve the performance of this particular function):
116 |  |
           * Cache the HashMaps, once they are constructed. */
117 |  |
118 |  |
         /**
119 |  |
          * Create a new <code>TranslateFunction</code> object.
120 |  |
          */
121 | 294 |
         public TranslateFunction() {}
122 |  |
123 |  |
124 |  |
         /** Returns a copy of the first argument in which
125 |  |
          * characters found in the second argument are replaced by
126 |  |
          * corresponding characters from the third argument.
127 |  |
          *
128 |  |
          * @param context the context at the point in the
129 |  |
          *         expression when the function is called
130 |  |
          * @param args a list that contains exactly three items
131 |  |
          *
132 |  |
          * @return a <code>String</code> built from <code>args.get(0)</code>
133 |  |
          *     in which occurrences of characters in <code>args.get(1)</code>
134 |  |
          *     are replaced by the corresponding characters in <code>args.get(2)</code>
135 |  |
          *
136 |  |
          * @throws FunctionCallException if <code>args</code> does not have exactly three items
137 |  |
          */
138 |  |
         public Object call(Context context,
139 |  |
                            List args) throws FunctionCallException
140 |  |
         {
141 | 306 |
             if (args.size() == 3) {
142 | 300 |
                 return evaluate( args.get(0),
143 |  |
                                  args.get(1),
144 |  |
                                  args.get(2),
145 |  |
                                  context.getNavigator() );
146 |  |
             }
147 |  |
148 | 6 |
             throw new FunctionCallException( "translate() requires three arguments." );
149 |  |
         }
150 |  |
151 |  |
         /**
152 |  |
          * Returns a copy of <code>strArg</code> in which
153 |  |
          * characters found in <code>fromArg</code> are replaced by
154 |  |
          * corresponding characters from <code>toArg</code>.
155 |  |
          * If necessary each argument is first converted to it string-value
156 |  |
          * as if by the XPath <code>string()</code> function.
157 |  |
          *
158 |  |
          * @param strArg the base string
159 |  |
          * @param fromArg the characters to be replaced
160 |  |
          * @param toArg the characters they will be replaced by
161 |  |
          * @param nav the <code>Navigator</code> used to calculate the string-values of the arguments.
162 |  |
          *
163 |  |
          * @return a copy of <code>strArg</code> in which
164 |  |
          *  characters found in <code>fromArg</code> are replaced by
165 |  |
          *  corresponding characters from <code>toArg</code>
166 |  |
          *
167 |  |
          * @throws FunctionCallException if one of the arguments is a malformed Unicode string;
168 |  |
          *     that is, if surrogate characters don't line up properly
169 |  |
          *
170 |  |
          */
171 |  |
         public static String evaluate(Object strArg,
172 |  |
                                       Object fromArg,
173 |  |
                                       Object toArg,
174 |  |
                                       Navigator nav) throws FunctionCallException
175 |  |
         {
176 | 300 |
             String inStr = StringFunction.evaluate( strArg, nav );
177 | 300 |
             String fromStr = StringFunction.evaluate( fromArg, nav );
178 | 300 |
             String toStr = StringFunction.evaluate( toArg, nav );
179 |  |
180 |  |
             // Initialize the mapping in a HashMap
181 | 300 |
             Map characterMap = new HashMap();
182 | 300 |
             String[] fromCharacters = toUnicodeCharacters(fromStr);
183 | 300 |
             String[] toCharacters = toUnicodeCharacters(toStr);
184 | 288 |
             int fromLen = fromCharacters.length;
185 | 288 |
             int toLen = toCharacters.length;
186 | 1128 |
             for ( int i = 0; i < fromLen; i++ ) {
187 | 840 |
                 String cFrom = fromCharacters[i];
188 | 840 |
                 if ( characterMap.containsKey( cFrom ) ) {
189 |  |
                     // We've seen the character before, ignore
190 | 24 |
                     continue;
191 |  |
                 }
192 |  |
193 | 816 |
                 if ( i < toLen ) {
194 |  |
                     // Will change
195 | 672 |
                     characterMap.put( cFrom, toCharacters[i] );
196 |  |
                 }
197 |  |
                 else {
198 |  |
                     // Will delete
199 | 144 |
                     characterMap.put( cFrom, null );
200 |  |
                 }
201 |  |
             }
202 |  |
203 |  |
             // Process the input string thru the map
204 | 288 |
             StringBuffer outStr = new StringBuffer( inStr.length() );
205 | 288 |
             String[] inCharacters = toUnicodeCharacters(inStr);
206 | 288 |
             int inLen = inCharacters.length;
207 | 1314 |
             for ( int i = 0; i < inLen; i++ ) {
208 | 1026 |
                 String cIn = inCharacters[i];
209 | 1026 |
                 if ( characterMap.containsKey( cIn ) ) {
210 | 822 |
                     String cTo = (String) characterMap.get( cIn );
211 | 822 |
                     if ( cTo != null ) {
212 | 678 |
                         outStr.append( cTo );
213 |  |
                     }
214 |  |
                 }
215 |  |
                 else {
216 | 204 |
                     outStr.append( cIn );
217 |  |
                 }
218 |  |
             }
219 |  |
220 | 288 |
             return outStr.toString();
221 |  |
         }
222 |  |
223 |  |
         private static String[] toUnicodeCharacters(String s) throws FunctionCallException {
224 |  |
225 | 888 |
             String[] result = new String[s.length()];
226 | 888 |
             int stringLength = 0;
227 | 3540 |
             for (int i = 0; i < s.length(); i++) {
228 | 2664 |
                 char c1 = s.charAt(i);
229 | 2664 |
                 if (isHighSurrogate(c1)) {
230 |  |
                     try {
231 | 54 |
                         char c2 = s.charAt(i+1);
232 | 54 |
                         if (isLowSurrogate(c2)) {
233 | 42 |
                             result[stringLength] = (c1 + "" + c2).intern();
234 | 42 |
                             i++;
235 |  |
                         }
236 |  |
                         else {
237 | 12 |
                             throw new FunctionCallException("Mismatched surrogate pair in translate function");
238 |  |
                         }
239 |  |
                     }
240 | 0 |
                     catch (StringIndexOutOfBoundsException ex) {
241 | 0 |
                         throw new FunctionCallException("High surrogate without low surrogate at end of string passed to translate function");
242 | 42 |
                     }
243 |  |
                 }
244 |  |
                 else {
245 | 2610 |
                     result[stringLength]=String.valueOf(c1).intern();
246 |  |
                 }
247 | 2652 |
                 stringLength++;
248 |  |
             }
249 |  |
250 | 876 |
             if (stringLength == result.length) return result;
251 |  |
252 |  |
             // trim array
253 | 42 |
             String[] trimmed = new String[stringLength];
254 | 42 |
             System.arraycopy(result, 0, trimmed, 0, stringLength);
255 | 42 |
             return trimmed;
256 |  |
257 |  |
         }
258 |  |
259 |  |
         private static boolean isHighSurrogate(char c) {
260 | 2664 |
             return c >= 0xD800 && c <= 0xDBFF;
261 |  |
         }
262 |  |
263 |  |
         private static boolean isLowSurrogate(char c) {
264 | 54 |
             return c >= 0xDC00 && c <= 0xDFFF;
265 |  |
         }
266 |  |
267 |  |
     }