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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.apache.commons.validator;
18  
19  import java.text.DateFormat;
20  import java.text.ParseException;
21  import java.text.SimpleDateFormat;
22  import java.util.Locale;
23  
24  /***
25   * <p>Perform date validations.</p>
26   * <p>
27   * This class is a Singleton; you can retrieve the instance via the
28   * getInstance() method.
29   * </p>
30   *
31   * @version $Revision: 478334 $ $Date: 2006-11-22 21:31:54 +0000 (Wed, 22 Nov 2006) $
32   * @since Validator 1.1
33   */
34  public class DateValidator {
35  
36      /***
37       * Singleton instance of this class.
38       */
39      private static final DateValidator DATE_VALIDATOR = new DateValidator();
40  
41      /***
42       * Returns the Singleton instance of this validator.
43       * @return A singleton instance of the DateValidator.
44       */
45      public static DateValidator getInstance() {
46          return DATE_VALIDATOR;
47      }
48  
49      /***
50       * Protected constructor for subclasses to use.
51       */
52      protected DateValidator() {
53          super();
54      }
55  
56      /***
57       * <p>Checks if the field is a valid date.  The pattern is used with
58       * <code>java.text.SimpleDateFormat</code>.  If strict is true, then the
59       * length will be checked so '2/12/1999' will not pass validation with
60       * the format 'MM/dd/yyyy' because the month isn't two digits.
61       * The setLenient method is set to <code>false</code> for all.</p>
62       *
63       * @param value The value validation is being performed on.
64       * @param datePattern The pattern passed to <code>SimpleDateFormat</code>.
65       * @param strict Whether or not to have an exact match of the datePattern.
66       * @return true if the date is valid.
67       */
68      public boolean isValid(String value, String datePattern, boolean strict) {
69  
70          if (value == null
71                  || datePattern == null
72                  || datePattern.length() <= 0) {
73  
74              return false;
75          }
76  
77          SimpleDateFormat formatter = new SimpleDateFormat(datePattern);
78          formatter.setLenient(false);
79  
80          try {
81              formatter.parse(value);
82          } catch(ParseException e) {
83              return false;
84          }
85  
86          if (strict && (datePattern.length() != value.length())) {
87              return false;
88          }
89  
90          return true;
91      }
92  
93      /***
94       * <p>Checks if the field is a valid date.  The <code>Locale</code> is
95       * used with <code>java.text.DateFormat</code>.  The setLenient method
96       * is set to <code>false</code> for all.</p>
97       *
98       * @param value The value validation is being performed on.
99       * @param locale The locale to use for the date format, defaults to the default
100      * system default if null.
101      * @return true if the date is valid.
102      */
103     public boolean isValid(String value, Locale locale) {
104 
105         if (value == null) {
106             return false;
107         }
108 
109         DateFormat formatter = null;
110         if (locale != null) {
111             formatter = DateFormat.getDateInstance(DateFormat.SHORT, locale);
112         } else {
113             formatter =
114                     DateFormat.getDateInstance(
115                             DateFormat.SHORT,
116                             Locale.getDefault());
117         }
118 
119         formatter.setLenient(false);
120 
121         try {
122             formatter.parse(value);
123         } catch(ParseException e) {
124             return false;
125         }
126 
127         return true;
128     }
129 
130 }