    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017package org.apache.commons.validator.routines;
    018
    019import java.text.DecimalFormat;
    020import java.text.Format;
    021
    022/**
    023 * <p><b>Currency Validation</b> and Conversion routines (<code>java.math.BigDecimal</code>).</p>
    024 *
    025 * <p>This is one implementation of a currency validator that has the following features:</p>
    026 *    <ul>
    027 *       <li>It is <i>lenient</i> about the presence of the <i>currency symbol</i></li>
    028 *       <li>It converts the currency to a <code>java.math.BigDecimal</code></li>
    029 *    </ul>
    030 *
    031 * <p>However any of the <i>number</i> validators can be used for <i>currency</i> validation.
    032 *    For example, if you wanted a <i>currency</i> validator that converts to a
    033 *    <code>java.lang.Integer</code> then you can simply instantiate an
    034 *    <code>IntegerValidator</code> with the appropriate <i>format type</i>:</p>
    035 *
    036 *    <p><code>... = new IntegerValidator(false, IntegerValidator.CURRENCY_FORMAT);</code></p>
    037 *
    038 * <p>Pick the appropriate validator, depending on the type (e.g Float, Double, Integer, Long etc)
    039 *    you want the currency converted to. One thing to note - only the CurrencyValidator
    040 *    implements <i>lenient</i> behavior regarding the currency symbol.</p>
    041 *
    042 * @version $Revision$
    043 * @since Validator 1.3.0
    044 */
    045public class CurrencyValidator extends BigDecimalValidator {
    046
    047    private static final long serialVersionUID = -4201640771171486514L;
    048
    049    private static final CurrencyValidator VALIDATOR = new CurrencyValidator();
    050
    051    /** DecimalFormat's currency symbol */
    052    private static final char CURRENCY_SYMBOL = '\u00A4';
    053
    054    /**
    055     * Return a singleton instance of this validator.
    056     * @return A singleton instance of the CurrencyValidator.
    057     */
    058    public static BigDecimalValidator getInstance() {
    059        return VALIDATOR;
    060    }
    061
    062    /**
    063     * Construct a <i>strict</i> instance.
    064     */
    065    public CurrencyValidator() {
    066        this(true, true);
    067    }
    068
    069    /**
    070     * Construct an instance with the specified strict setting.
    071     *
    072     * @param strict <code>true</code> if strict
    073     *        <code>Format</code> parsing should be used.
    074     * @param allowFractions <code>true</code> if fractions are
    075     *        allowed or <code>false</code> if integers only.
    076     */
    077    public CurrencyValidator(boolean strict, boolean allowFractions) {
    078        super(strict, CURRENCY_FORMAT, allowFractions);
    079    }
    080
    081    /**
    082     * <p>Parse the value with the specified <code>Format</code>.</p>
    083     *
    084     * <p>This implementation is lenient whether the currency symbol
    085     *    is present or not. The default <code>NumberFormat</code>
    086     *    behavior is for the parsing to "fail" if the currency
    087     *    symbol is missing. This method re-parses with a format
    088     *    without the currency symbol if it fails initially.</p>
    089     *
    090     * @param value The value to be parsed.
    091     * @param formatter The Format to parse the value with.
    092     * @return The parsed value if valid or <code>null</code> if invalid.
    093     */
    094    @Override
    095    protected Object parse(String value, Format formatter) {
    096
    097        // Initial parse of the value
    098        Object parsedValue = super.parse(value, formatter);
    099        if (parsedValue != null || !(formatter instanceof DecimalFormat)) {
    100            return parsedValue;
    101        }
    102
    103        // Re-parse using a pattern without the currency symbol
    104        DecimalFormat decimalFormat = (DecimalFormat)formatter;
    105        String pattern = decimalFormat.toPattern();
    106        if (pattern.indexOf(CURRENCY_SYMBOL) >= 0) {
    107            StringBuilder buffer = new StringBuilder(pattern.length());
    108            for (int i = 0; i < pattern.length(); i++) {
    109                if (pattern.charAt(i) != CURRENCY_SYMBOL) {
    110                    buffer.append(pattern.charAt(i));
    111                }
    112            }
    113            decimalFormat.applyPattern(buffer.toString());
    114            parsedValue = super.parse(value, decimalFormat);
    115        }
    116        return parsedValue;
    117    }
    118}