View Javadoc

    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.routines;
    18
    19  import java.text.DecimalFormat;
    20  import java.text.Format;
    21
    22  /***
    23   * <p><b>Currency Validation</b> and Conversion routines (<code>java.math.BigDecimal</code>).</p>
    24   *
    25   * <p>This is one implementation of a currency validator that has the following features:</p>
    26   *    <ul>
    27   *       <li>It is <i>lenient</i> about the the presence of the <i>currency symbol</i></li>
    28   *       <li>It converts the currency to a <code>java.math.BigDecimal</code></li>
    29   *    </ul>
    30   *
    31   * <p>However any of the <i>number</i> validators can be used for <i>currency</i> validation.
    32   *    For example, if you wanted a <i>currency</i> validator that converts to a
    33   *    <code>java.lang.Integer</code> then you can simply instantiate an
    34   *    <code>IntegerValidator</code> with the appropriate <i>format type</i>:</p>
    35   *
    36   *    <p><code>... = new IntegerValidator(false, IntegerValidator.CURRENCY_FORMAT);</code></p>
    37   *
    38   * <p>Pick the appropriate validator, depending on the type (e.g Float, Double, Integer, Long etc)
    39   *    you want the currency converted to. One thing to note - only the CurrencyValidator
    40   *    implements <i>lenient</i> behaviour regarding the currency symbol.</p>
    41   *
    42   * @version $Revision: 478334 $ $Date: 2006-11-22 21:31:54 +0000 (Wed, 22 Nov 2006) $
    43   * @since Validator 1.3.0
    44   */
    45  public class CurrencyValidator extends BigDecimalValidator {
    46
    47      private static final CurrencyValidator VALIDATOR = new CurrencyValidator();
    48
    49      /*** DecimalFormat's currency symbol */
    50      private static final char CURRENCY_SYMBOL = '\u00A4';
    51
    52      /***
    53       * Return a singleton instance of this validator.
    54       * @return A singleton instance of the CurrencyValidator.
    55       */
    56      public static BigDecimalValidator getInstance() {
    57          return VALIDATOR;
    58      }
    59
    60      /***
    61       * Construct a <i>strict</i> instance.
    62       */
    63      public CurrencyValidator() {
    64          this(true, true);
    65      }
    66
    67      /***
    68       * Construct an instance with the specified strict setting.
    69       *
    70       * @param strict <code>true</code> if strict
    71       *        <code>Format</code> parsing should be used.
    72       * @param allowFractions <code>true</code> if fractions are
    73       *        allowed or <code>false</code> if integers only.
    74       */
    75      public CurrencyValidator(boolean strict, boolean allowFractions) {
    76          super(strict, CURRENCY_FORMAT, allowFractions);
    77      }
    78
    79      /***
    80       * <p>Parse the value with the specified <code>Format</code>.</p>
    81       *
    82       * <p>This implementation is lenient whether the currency symbol
    83       *    is present or not. The default <code>NumberFormat</code>
    84       *    behaviour is for the parsing to "fail" if the currency
    85       *    symbol is missing. This method re-parses with a format
    86       *    without the currency symbol if it fails initially.</p>
    87       *
    88       * @param value The value to be parsed.
    89       * @param formatter The Format to parse the value with.
    90       * @return The parsed value if valid or <code>null</code> if invalid.
    91       */
    92      protected Object parse(String value, Format formatter) {
    93
    94          // Initial parse of the value
    95          Object parsedValue = super.parse(value, formatter);
    96          if (parsedValue != null || !(formatter instanceof DecimalFormat)) {
    97              return parsedValue;
    98          }
    99
    100         // Re-parse using a pattern without the currency symbol
    101         DecimalFormat decimalFormat = (DecimalFormat)formatter;
    102         String pattern = decimalFormat.toPattern();
    103         if (pattern.indexOf(CURRENCY_SYMBOL) >= 0) {
    104             StringBuffer buffer = new StringBuffer(pattern.length());
    105             for (int i = 0; i < pattern.length(); i++) {
    106                 if (pattern.charAt(i) != CURRENCY_SYMBOL) {
    107                     buffer.append(pattern.charAt(i));
    108                 }
    109             }
    110             decimalFormat.applyPattern(buffer.toString());
    111             parsedValue = super.parse(value, decimalFormat);
    112         }
    113         return parsedValue;
    114     }
    115 }