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 */ 017package org.apache.commons.validator.routines; 018 019import java.text.DecimalFormat; 020import java.text.Format; 021import 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 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 $Revision$ 046 * @since Validator 1.3.0 047 */ 048public class PercentValidator extends BigDecimalValidator { 049 050 private static final long serialVersionUID = -3508241924961535772L; 051 052 private static final PercentValidator VALIDATOR = new PercentValidator(); 053 054 /** DecimalFormat's percent (thousand multiplier) symbol */ 055 private static final char PERCENT_SYMBOL = '%'; 056 057 private static final BigDecimal POINT_ZERO_ONE = new BigDecimal("0.01"); 058 059 /** 060 * Return a singleton instance of this validator. 061 * @return A singleton instance of the PercentValidator. 062 */ 063 public static BigDecimalValidator getInstance() { 064 return VALIDATOR; 065 } 066 067 /** 068 * Construct a <i>strict</i> instance. 069 */ 070 public PercentValidator() { 071 this(true); 072 } 073 074 /** 075 * Construct an instance with the specified strict setting. 076 * 077 * @param strict <code>true</code> if strict 078 * <code>Format</code> parsing should be used. 079 */ 080 public PercentValidator(boolean strict) { 081 super(strict, PERCENT_FORMAT, true); 082 } 083 084 /** 085 * <p>Parse the value with the specified <code>Format</code>.</p> 086 * 087 * <p>This implementation is lenient whether the currency symbol 088 * is present or not. The default <code>NumberFormat</code> 089 * behavior is for the parsing to "fail" if the currency 090 * symbol is missing. This method re-parses with a format 091 * without the currency symbol if it fails initially.</p> 092 * 093 * @param value The value to be parsed. 094 * @param formatter The Format to parse the value with. 095 * @return The parsed value if valid or <code>null</code> if invalid. 096 */ 097 @Override 098 protected Object parse(String value, Format formatter) { 099 100 // Initial parse of the value 101 BigDecimal parsedValue = (BigDecimal)super.parse(value, formatter); 102 if (parsedValue != null || !(formatter instanceof DecimalFormat)) { 103 return parsedValue; 104 } 105 106 // Re-parse using a pattern without the percent symbol 107 DecimalFormat decimalFormat = (DecimalFormat)formatter; 108 String pattern = decimalFormat.toPattern(); 109 if (pattern.indexOf(PERCENT_SYMBOL) >= 0) { 110 StringBuilder buffer = new StringBuilder(pattern.length()); 111 for (int i = 0; i < pattern.length(); i++) { 112 if (pattern.charAt(i) != PERCENT_SYMBOL) { 113 buffer.append(pattern.charAt(i)); 114 } 115 } 116 decimalFormat.applyPattern(buffer.toString()); 117 parsedValue = (BigDecimal)super.parse(value, decimalFormat); 118 119 // If parsed OK, divide by 100 to get percent 120 if (parsedValue != null) { 121 parsedValue = parsedValue.multiply(POINT_ZERO_ONE); 122 } 123 124 } 125 return parsedValue; 126 } 127}