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: */
017: package org.apache.commons.validator.routines;
018:
019: import java.text.DecimalFormat;
020: import 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 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> behaviour regarding the currency symbol.</p>
041: *
042: * @version $Revision: 478334 $ $Date: 2006-11-22 21:31:54 +0000 (Wed, 22 Nov 2006) $
043: * @since Validator 1.3.0
044: */
045: public class CurrencyValidator extends BigDecimalValidator {
046:
047: private static final CurrencyValidator VALIDATOR = new CurrencyValidator();
048:
049: /** DecimalFormat's currency symbol */
050: private static final char CURRENCY_SYMBOL = '\u00A4';
051:
052: /**
053: * Return a singleton instance of this validator.
054: * @return A singleton instance of the CurrencyValidator.
055: */
056: public static BigDecimalValidator getInstance() {
057: return VALIDATOR;
058: }
059:
060: /**
061: * Construct a <i>strict</i> instance.
062: */
063: public CurrencyValidator() {
064: this (true, true);
065: }
066:
067: /**
068: * Construct an instance with the specified strict setting.
069: *
070: * @param strict <code>true</code> if strict
071: * <code>Format</code> parsing should be used.
072: * @param allowFractions <code>true</code> if fractions are
073: * allowed or <code>false</code> if integers only.
074: */
075: public CurrencyValidator(boolean strict, boolean allowFractions) {
076: super (strict, CURRENCY_FORMAT, allowFractions);
077: }
078:
079: /**
080: * <p>Parse the value with the specified <code>Format</code>.</p>
081: *
082: * <p>This implementation is lenient whether the currency symbol
083: * is present or not. The default <code>NumberFormat</code>
084: * behaviour is for the parsing to "fail" if the currency
085: * symbol is missing. This method re-parses with a format
086: * without the currency symbol if it fails initially.</p>
087: *
088: * @param value The value to be parsed.
089: * @param formatter The Format to parse the value with.
090: * @return The parsed value if valid or <code>null</code> if invalid.
091: */
092: protected Object parse(String value, Format formatter) {
093:
094: // Initial parse of the value
095: Object parsedValue = super .parse(value, formatter);
096: if (parsedValue != null
097: || !(formatter instanceof DecimalFormat)) {
098: return parsedValue;
099: }
100:
101: // Re-parse using a pattern without the currency symbol
102: DecimalFormat decimalFormat = (DecimalFormat) formatter;
103: String pattern = decimalFormat.toPattern();
104: if (pattern.indexOf(CURRENCY_SYMBOL) >= 0) {
105: StringBuffer buffer = new StringBuffer(pattern.length());
106: for (int i = 0; i < pattern.length(); i++) {
107: if (pattern.charAt(i) != CURRENCY_SYMBOL) {
108: buffer.append(pattern.charAt(i));
109: }
110: }
111: decimalFormat.applyPattern(buffer.toString());
112: parsedValue = super.parse(value, decimalFormat);
113: }
114: return parsedValue;
115: }
116: }
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