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 import java.math.BigDecimal; 022 023 /** 024 * <p><b>Percentage Validation</b> and Conversion routines (<code>java.math.BigDecimal</code>).</p> 025 * 026 * <p>This is one implementation of a percent validator that has the following features:</p> 027 * <ul> 028 * <li>It is <i>lenient</i> about the the presence of the <i>percent symbol</i></li> 029 * <li>It converts the percent to a <code>java.math.BigDecimal</code></li> 030 * </ul> 031 * 032 * <p>However any of the <i>number</i> validators can be used for <i>percent</i> validation. 033 * For example, if you wanted a <i>percent</i> validator that converts to a 034 * <code>java.lang.Float</code> then you can simply instantiate an 035 * <code>FloatValidator</code> with the appropriate <i>format type</i>:</p> 036 * 037 * <p><code>... = new FloatValidator(false, FloatValidator.PERCENT_FORMAT);</code></p> 038 * 039 * <p>Pick the appropriate validator, depending on the type (i.e Float, Double or BigDecimal) 040 * you want the percent converted to. Please note, it makes no sense to use 041 * one of the validators that doesn't handle fractions (i.e. byte, short, integer, long 042 * and BigInteger) since percentages are converted to fractions (i.e <code>50%</code> is 043 * converted to <code>0.5</code>).</p> 044 * 045 * @version $Revision: 493905 $ $Date: 2007-01-08 03:11:38 +0100 (Mo, 08. Jan 2007) $ 046 * @since Validator 1.3.0 047 */ 048 public class PercentValidator extends BigDecimalValidator { 049 050 private static final PercentValidator VALIDATOR = new PercentValidator(); 051 052 /** DecimalFormat's percent (thousand multiplier) symbol */ 053 private static final char PERCENT_SYMBOL = '%'; 054 055 private static final BigDecimal POINT_ZERO_ONE = new BigDecimal("0.01"); 056 057 /** 058 * Return a singleton instance of this validator. 059 * @return A singleton instance of the PercentValidator. 060 */ 061 public static BigDecimalValidator getInstance() { 062 return VALIDATOR; 063 } 064 065 /** 066 * Construct a <i>strict</i> instance. 067 */ 068 public PercentValidator() { 069 this(true); 070 } 071 072 /** 073 * Construct an instance with the specified strict setting. 074 * 075 * @param strict <code>true</code> if strict 076 * <code>Format</code> parsing should be used. 077 */ 078 public PercentValidator(boolean strict) { 079 super(strict, PERCENT_FORMAT, true); 080 } 081 082 /** 083 * <p>Parse the value with the specified <code>Format</code>.</p> 084 * 085 * <p>This implementation is lenient whether the currency symbol 086 * is present or not. The default <code>NumberFormat</code> 087 * behaviour is for the parsing to "fail" if the currency 088 * symbol is missing. This method re-parses with a format 089 * without the currency symbol if it fails initially.</p> 090 * 091 * @param value The value to be parsed. 092 * @param formatter The Format to parse the value with. 093 * @return The parsed value if valid or <code>null</code> if invalid. 094 */ 095 protected Object parse(String value, Format formatter) { 096 097 // Initial parse of the value 098 BigDecimal parsedValue = (BigDecimal)super.parse(value, formatter); 099 if (parsedValue != null || !(formatter instanceof DecimalFormat)) { 100 return parsedValue; 101 } 102 103 // Re-parse using a pattern without the percent symbol 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 // If parsed OK, divide by 100 to get percent 117 if (parsedValue != null) { 118 parsedValue = parsedValue.multiply(POINT_ZERO_ONE); 119 } 120 121 } 122 return parsedValue; 123 } 124 }