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.math.BigDecimal;
20 import java.text.DecimalFormat;
21 import java.text.Format;
22
23 /**
24 * <p><b>Percentage Validation</b> and Conversion routines (<code>java.math.BigDecimal</code>).</p>
25 *
26 * <p>This is one implementation of a percent validator that has the following features:</p>
27 * <ul>
28 * <li>It is <i>lenient</i> about the presence of the <i>percent symbol</i></li>
29 * <li>It converts the percent to a <code>java.math.BigDecimal</code></li>
30 * </ul>
31 *
32 * <p>However any of the <i>number</i> validators can be used for <i>percent</i> validation.
33 * For example, if you wanted a <i>percent</i> validator that converts to a
34 * <code>java.lang.Float</code> then you can simply instantiate an
35 * <code>FloatValidator</code> with the appropriate <i>format type</i>:</p>
36 *
37 * <p><code>... = new FloatValidator(false, FloatValidator.PERCENT_FORMAT);</code></p>
38 *
39 * <p>Pick the appropriate validator, depending on the type (i.e Float, Double or BigDecimal)
40 * you want the percent converted to. Please note, it makes no sense to use
41 * one of the validators that doesn't handle fractions (i.e. byte, short, integer, long
42 * and BigInteger) since percentages are converted to fractions (i.e <code>50%</code> is
43 * converted to <code>0.5</code>).</p>
44 *
45 * @since 1.3.0
46 */
47 public class PercentValidator extends BigDecimalValidator {
48
49 private static final long serialVersionUID = -3508241924961535772L;
50
51 private static final PercentValidator VALIDATOR = new PercentValidator();
52
53 /** DecimalFormat's percent (thousand multiplier) symbol */
54 private static final char PERCENT_SYMBOL = '%';
55
56 private static final BigDecimal POINT_ZERO_ONE = new BigDecimal("0.01");
57
58 /**
59 * Gets the singleton instance of this validator.
60 * @return A singleton instance of the PercentValidator.
61 */
62 public static BigDecimalValidator getInstance() {
63 return VALIDATOR;
64 }
65
66 /**
67 * Constructs a <i>strict</i> instance.
68 */
69 public PercentValidator() {
70 this(true);
71 }
72
73 /**
74 * Constructs an instance with the specified strict setting.
75 *
76 * @param strict {@code true} if strict
77 * <code>Format</code> parsing should be used.
78 */
79 public PercentValidator(final boolean strict) {
80 super(strict, PERCENT_FORMAT, true);
81 }
82
83 /**
84 * <p>Parse the value with the specified <code>Format</code>.</p>
85 *
86 * <p>This implementation is lenient whether the currency symbol
87 * is present or not. The default <code>NumberFormat</code>
88 * behavior is for the parsing to "fail" if the currency
89 * symbol is missing. This method re-parses with a format
90 * without the currency symbol if it fails initially.</p>
91 *
92 * @param value The value to be parsed.
93 * @param formatter The Format to parse the value with.
94 * @return The parsed value if valid or {@code null} if invalid.
95 */
96 @Override
97 protected Object parse(final String value, final Format formatter) {
98
99 // Initial parse of the value
100 BigDecimal parsedValue = (BigDecimal) super.parse(value, formatter);
101 if (parsedValue != null || !(formatter instanceof DecimalFormat)) {
102 return parsedValue;
103 }
104
105 // Re-parse using a pattern without the percent symbol
106 final DecimalFormat decimalFormat = (DecimalFormat) formatter;
107 final String pattern = decimalFormat.toPattern();
108 if (pattern.indexOf(PERCENT_SYMBOL) >= 0) {
109 final StringBuilder buffer = new StringBuilder(pattern.length());
110 for (int i = 0; i < pattern.length(); i++) {
111 if (pattern.charAt(i) != PERCENT_SYMBOL) {
112 buffer.append(pattern.charAt(i));
113 }
114 }
115 decimalFormat.applyPattern(buffer.toString());
116 parsedValue = (BigDecimal) super.parse(value, decimalFormat);
117
118 // If parsed OK, divide by 100 to get percent
119 if (parsedValue != null) {
120 parsedValue = parsedValue.multiply(POINT_ZERO_ONE);
121 }
122
123 }
124 return parsedValue;
125 }
126 }