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1   /*
2    * Copyright 2010 Werner Guttmann
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.exolab.castor.util;
17  
18  import java.util.regex.Pattern;
19  import java.util.regex.PatternSyntaxException;
20  
21  /**
22   * An implementation of {@link RegExpEvaluator} that uses the Java Regular
23   * Expression library.
24   * 
25   * @author <a href="mailto:george76@hotmail.com">George Varghese</a>
26   * @since 1.3.2
27   **/
28  public class SunRegExpEvaluator implements RegExpEvaluator {
29  
30      /**
31       * The Regular expression
32       **/
33      private Pattern _pattern;
34  
35      /**
36       * Sets the regular expression to match against during a call to #matches
37       * 
38       * @param rexpr
39       *            the regular expression
40       **/
41      public void setExpression(String rexpr) {
42  
43          if (rexpr != null) {
44              try {
45                  // -- patch and compile expression
46                  _pattern = Pattern.compile(rexpr);
47              } catch (PatternSyntaxException ex) {
48                  String err = "RegExp Syntax error: ";
49                  err += ex.getMessage();
50                  err += " ; error occured with the following "
51                          + "regular expression: " + rexpr;
52  
53                  throw new IllegalArgumentException(err, ex);
54              }
55          }
56      }
57  
58      /**
59       * Returns true if the given String is matched by the regular expression of
60       * this RegExpEvaluator
61       * 
62       * @param value
63       *            the String to check the production of
64       * @return true if the given string matches the regular expression of this
65       *         RegExpEvaluator
66       * @see #setExpression
67       **/
68      public boolean matches(String value) {
69          if (_pattern != null) {
70              return _pattern.matcher(value).matches();
71          }
72          return true;
73      }
74  
75  }
76