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 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> behavior regarding the currency symbol.</p>
41 *
42 * @since 1.3.0
43 */
44 public class CurrencyValidator extends BigDecimalValidator {
45
46 private static final long serialVersionUID = -4201640771171486514L;
47
48 private static final CurrencyValidator VALIDATOR = new CurrencyValidator();
49
50 /** DecimalFormat's currency symbol */
51 private static final char CURRENCY_SYMBOL = '\u00A4';
52
53 /**
54 * Gets the singleton instance of this validator.
55 * @return A singleton instance of the CurrencyValidator.
56 */
57 public static BigDecimalValidator getInstance() {
58 return VALIDATOR;
59 }
60
61 /**
62 * Constructs a <i>strict</i> instance.
63 */
64 public CurrencyValidator() {
65 this(true, true);
66 }
67
68 /**
69 * Constructs an instance with the specified strict setting.
70 *
71 * @param strict {@code true} if strict
72 * <code>Format</code> parsing should be used.
73 * @param allowFractions {@code true} if fractions are
74 * allowed or {@code false} if integers only.
75 */
76 public CurrencyValidator(final boolean strict, final boolean allowFractions) {
77 super(strict, CURRENCY_FORMAT, allowFractions);
78 }
79
80 /**
81 * <p>Parse the value with the specified <code>Format</code>.</p>
82 *
83 * <p>This implementation is lenient whether the currency symbol
84 * is present or not. The default <code>NumberFormat</code>
85 * behavior is for the parsing to "fail" if the currency
86 * symbol is missing. This method re-parses with a format
87 * without the currency symbol if it fails initially.</p>
88 *
89 * @param value The value to be parsed.
90 * @param formatter The Format to parse the value with.
91 * @return The parsed value if valid or {@code null} if invalid.
92 */
93 @Override
94 protected Object parse(final String value, final Format formatter) {
95
96 // Initial parse of the value
97 Object parsedValue = super.parse(value, formatter);
98 if (parsedValue != null || !(formatter instanceof DecimalFormat)) {
99 return parsedValue;
100 }
101
102 // Re-parse using a pattern without the currency symbol
103 final DecimalFormat decimalFormat = (DecimalFormat) formatter;
104 final String pattern = decimalFormat.toPattern();
105 if (pattern.indexOf(CURRENCY_SYMBOL) >= 0) {
106 final StringBuilder buffer = new StringBuilder(pattern.length());
107 for (int i = 0; i < pattern.length(); i++) {
108 if (pattern.charAt(i) != CURRENCY_SYMBOL) {
109 buffer.append(pattern.charAt(i));
110 }
111 }
112 decimalFormat.applyPattern(buffer.toString());
113 parsedValue = super.parse(value, decimalFormat);
114 }
115 return parsedValue;
116 }
117 }