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    1   /*
    2    * $Id: DateValidator.java 366933 2006-01-07 22:51:01Z niallp $
    3    * $Rev: 366933 $
    4    * $Date: 2006-01-07 22:51:01 +0000 (Sat, 07 Jan 2006) $
    5    *
    6    * ====================================================================
    7    * Copyright 2001-2006 The Apache Software Foundation
    8    *
    9    * Licensed under the Apache License, Version 2.0 (the "License");
    10   * you may not use this file except in compliance with the License.
    11   * You may obtain a copy of the License at
    12   *
    13   *     http://www.apache.org/licenses/LICENSE-2.0
    14   *
    15   * Unless required by applicable law or agreed to in writing, software
    16   * distributed under the License is distributed on an "AS IS" BASIS,
    17   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    18   * See the License for the specific language governing permissions and
    19   * limitations under the License.
    20   */
    21
    22  package org.apache.commons.validator;
    23
    24  import java.text.DateFormat;
    25  import java.text.ParseException;
    26  import java.text.SimpleDateFormat;
    27  import java.util.Locale;
    28
    29  /***
    30   * <p>Perform date validations.</p>
    31   * <p>
    32   * This class is a Singleton; you can retrieve the instance via the
    33   * getInstance() method.
    34   * </p>
    35   *
    36   * @since Validator 1.1
    37   */
    38  public class DateValidator {
    39
    40      /***
    41       * Singleton instance of this class.
    42       */
    43      private static final DateValidator DATE_VALIDATOR = new DateValidator();
    44
    45      /***
    46       * Returns the Singleton instance of this validator.
    47       * @return A singleton instance of the DateValidator.
    48       */
    49      public static DateValidator getInstance() {
    50          return DATE_VALIDATOR;
    51      }
    52
    53      /***
    54       * Protected constructor for subclasses to use.
    55       */
    56      protected DateValidator() {
    57          super();
    58      }
    59
    60      /***
    61       * <p>Checks if the field is a valid date.  The pattern is used with
    62       * <code>java.text.SimpleDateFormat</code>.  If strict is true, then the
    63       * length will be checked so '2/12/1999' will not pass validation with
    64       * the format 'MM/dd/yyyy' because the month isn't two digits.
    65       * The setLenient method is set to <code>false</code> for all.</p>
    66       *
    67       * @param value The value validation is being performed on.
    68       * @param datePattern The pattern passed to <code>SimpleDateFormat</code>.
    69       * @param strict Whether or not to have an exact match of the datePattern.
    70       * @return true if the date is valid.
    71       */
    72      public boolean isValid(String value, String datePattern, boolean strict) {
    73
    74          if (value == null
    75                  || datePattern == null
    76                  || datePattern.length() <= 0) {
    77
    78              return false;
    79          }
    80
    81          SimpleDateFormat formatter = new SimpleDateFormat(datePattern);
    82          formatter.setLenient(false);
    83
    84          try {
    85              formatter.parse(value);
    86          } catch(ParseException e) {
    87              return false;
    88          }
    89
    90          if (strict && (datePattern.length() != value.length())) {
    91              return false;
    92          }
    93
    94          return true;
    95      }
    96
    97      /***
    98       * <p>Checks if the field is a valid date.  The <code>Locale</code> is
    99       * used with <code>java.text.DateFormat</code>.  The setLenient method
    100      * is set to <code>false</code> for all.</p>
    101      *
    102      * @param value The value validation is being performed on.
    103      * @param locale The locale to use for the date format, defaults to the default
    104      * system default if null.
    105      * @return true if the date is valid.
    106      */
    107     public boolean isValid(String value, Locale locale) {
    108
    109         if (value == null) {
    110             return false;
    111         }
    112
    113         DateFormat formatter = null;
    114         if (locale != null) {
    115             formatter = DateFormat.getDateInstance(DateFormat.SHORT, locale);
    116         } else {
    117             formatter =
    118                     DateFormat.getDateInstance(
    119                             DateFormat.SHORT,
    120                             Locale.getDefault());
    121         }
    122
    123         formatter.setLenient(false);
    124
    125         try {
    126             formatter.parse(value);
    127         } catch(ParseException e) {
    128             return false;
    129         }
    130
    131         return true;
    132     }
    133
    134 }