1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17 package org.apache.commons.validator.routines;
18
19 import java.text.DecimalFormat;
20 import java.text.Format;
21 import java.math.BigDecimal;
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 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 * @version $Revision: 478334 $ $Date: 2006-11-22 21:31:54 +0000 (Wed, 22 Nov 2006) $
46 * @since Validator 1.3.0
47 */
48 public class PercentValidator extends BigDecimalValidator {
49
50 private static final PercentValidator VALIDATOR = new PercentValidator();
51
52 /*** DecimalFormat's percent (thousand multiplier) symbol */
53 private static final char PERCENT_SYMBOL = '%';
54
55 private static final BigDecimal POINT_ZERO_ONE = new BigDecimal("0.01");
56
57 /***
58 * Return a singleton instance of this validator.
59 * @return A singleton instance of the PercentValidator.
60 */
61 public static BigDecimalValidator getInstance() {
62 return VALIDATOR;
63 }
64
65 /***
66 * Construct a <i>strict</i> instance.
67 */
68 public PercentValidator() {
69 this(true);
70 }
71
72 /***
73 * Construct an instance with the specified strict setting.
74 *
75 * @param strict <code>true</code> if strict
76 * <code>Format</code> parsing should be used.
77 */
78 public PercentValidator(boolean strict) {
79 super(strict, PERCENT_FORMAT, true);
80 }
81
82 /***
83 * <p>Parse the value with the specified <code>Format</code>.</p>
84 *
85 * <p>This implementation is lenient whether the currency symbol
86 * is present or not. The default <code>NumberFormat</code>
87 * behaviour is for the parsing to "fail" if the currency
88 * symbol is missing. This method re-parses with a format
89 * without the currency symbol if it fails initially.</p>
90 *
91 * @param value The value to be parsed.
92 * @param formatter The Format to parse the value with.
93 * @return The parsed value if valid or <code>null</code> if invalid.
94 */
95 protected Object parse(String value, Format formatter) {
96
97
98 BigDecimal parsedValue = (BigDecimal)super.parse(value, formatter);
99 if (parsedValue != null || !(formatter instanceof DecimalFormat)) {
100 return parsedValue;
101 }
102
103
104 DecimalFormat decimalFormat = (DecimalFormat)formatter;
105 String pattern = decimalFormat.toPattern();
106 if (pattern.indexOf(PERCENT_SYMBOL) >= 0) {
107 StringBuffer buffer = new StringBuffer(pattern.length());
108 for (int i = 0; i < pattern.length(); i++) {
109 if (pattern.charAt(i) != PERCENT_SYMBOL) {
110 buffer.append(pattern.charAt(i));
111 }
112 }
113 decimalFormat.applyPattern(buffer.toString());
114 parsedValue = (BigDecimal)super.parse(value, decimalFormat);
115
116
117 if (parsedValue != null) {
118 parsedValue = parsedValue.multiply(POINT_ZERO_ONE);
119 }
120
121 }
122 return parsedValue;
123 }
124 }