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1   /*
2    * Copyright 2001-2004 The Apache Software Foundation.
3    * 
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    * 
8    *      http://www.apache.org/licenses/LICENSE-2.0
9    * 
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */ 
16  package org.apache.commons.betwixt.strategy;
17  
18  import org.apache.commons.betwixt.XMLUtils;
19  
20  /***
21   * <code>NameMapper</code> implementation that processes a name by replacing or stripping
22   * illegal characters before passing result down the chain.
23   * 
24   * @author Robert Burrell Donkin
25   * @since 0.5
26   */
27  public class BadCharacterReplacingNMapper implements NameMapper {
28      /*** Next mapper in chain, possibly null */
29      private NameMapper chainedMapper;
30      /*** Replacement character, possibly null */
31      private Character replacement = null;
32      
33      /***
34        * Constructs a replacing mapper which delegates to given mapper.
35        * @param chainedMapper next link in processing chain, possibly null
36        */
37      public BadCharacterReplacingNMapper(NameMapper chainedMapper) {
38          this.chainedMapper = chainedMapper;
39      }	
40  
41      /***
42        * Gets the character that should be used to replace bad characters
43        * if null then bad characters will be deleted.
44        * @return the replacement Character possibly null
45        */
46      public Character getReplacement() {
47          return replacement;
48      }
49      
50      /***
51        * Sets the character that should be used to replace bad characters.
52        * @param replacement the Charcter to be used for replacement if not null.
53        * Otherwise, indicates that illegal characters should be deleted.
54        */
55      public void setReplacement( Character replacement ) {
56          this.replacement = replacement;
57      } 
58  
59      /***
60       * This implementation processes characters which are not allowed in xml
61       * element names and then returns the result from the next link in the chain.
62       * This processing consists of deleting them if no replacement character
63       * has been set. 
64       * Otherwise, the character will be replaced.
65       *  
66       * @param typeName the string to convert 
67       * @return the processed input
68       */
69      public String mapTypeToElementName(String typeName) {
70          
71          StringBuffer buffer = new StringBuffer( typeName );
72          for (int i=0, size = buffer.length(); i< size; i++) {
73              char nextChar = buffer.charAt( i );
74              boolean bad = false;
75              if ( i==0 ) {
76                  bad = !XMLUtils.isNameStartChar( nextChar );
77              } else {
78                  bad = !XMLUtils.isNameChar( nextChar );
79              }
80                  
81              if (bad) {
82                  if ( replacement != null ) {
83                      buffer.setCharAt( i, replacement.charValue() );
84                  } else {
85                      // delete
86                      buffer.deleteCharAt( i );
87                      i--;
88                      size--;
89                  }
90              }
91          }
92          
93          if ( buffer.length() == 0 ) {
94              throw new IllegalArgumentException(
95  "Element name contains no legal characters and no replacements have been set.");
96          }
97          
98          typeName = buffer.toString();
99          
100         if ( chainedMapper == null ) {
101             return typeName;
102         }
103         return chainedMapper.mapTypeToElementName( typeName );
104     }
105 }