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.math3.util; 018 019 import java.io.Serializable; 020 import java.util.Collection; 021 import java.util.HashMap; 022 import java.util.Map; 023 import java.util.Set; 024 025 import org.apache.commons.math3.exception.MathIllegalArgumentException; 026 027 /** 028 * This TansformerMap automates the transformation of mixed object types. 029 * It provides a means to set NumberTransformers that will be selected 030 * based on the Class of the object handed to the Maps 031 * <code>double transform(Object o)</code> method. 032 * @version $Id: TransformerMap.java 1416643 2012-12-03 19:37:14Z tn $ 033 */ 034 public class TransformerMap implements NumberTransformer, Serializable { 035 036 /** Serializable version identifier */ 037 private static final long serialVersionUID = 4605318041528645258L; 038 039 /** 040 * A default Number Transformer for Numbers and numeric Strings. 041 */ 042 private NumberTransformer defaultTransformer = null; 043 044 /** 045 * The internal Map. 046 */ 047 private Map<Class<?>, NumberTransformer> map = null; 048 049 /** 050 * Build a map containing only the default transformer. 051 */ 052 public TransformerMap() { 053 map = new HashMap<Class<?>, NumberTransformer>(); 054 defaultTransformer = new DefaultTransformer(); 055 } 056 057 /** 058 * Tests if a Class is present in the TransformerMap. 059 * @param key Class to check 060 * @return true|false 061 */ 062 public boolean containsClass(Class<?> key) { 063 return map.containsKey(key); 064 } 065 066 /** 067 * Tests if a NumberTransformer is present in the TransformerMap. 068 * @param value NumberTransformer to check 069 * @return true|false 070 */ 071 public boolean containsTransformer(NumberTransformer value) { 072 return map.containsValue(value); 073 } 074 075 /** 076 * Returns the Transformer that is mapped to a class 077 * if mapping is not present, this returns null. 078 * @param key The Class of the object 079 * @return the mapped NumberTransformer or null. 080 */ 081 public NumberTransformer getTransformer(Class<?> key) { 082 return map.get(key); 083 } 084 085 /** 086 * Sets a Class to Transformer Mapping in the Map. If 087 * the Class is already present, this overwrites that 088 * mapping. 089 * @param key The Class 090 * @param transformer The NumberTransformer 091 * @return the replaced transformer if one is present 092 */ 093 public NumberTransformer putTransformer(Class<?> key, NumberTransformer transformer) { 094 return map.put(key, transformer); 095 } 096 097 /** 098 * Removes a Class to Transformer Mapping in the Map. 099 * @param key The Class 100 * @return the removed transformer if one is present or 101 * null if none was present. 102 */ 103 public NumberTransformer removeTransformer(Class<?> key) { 104 return map.remove(key); 105 } 106 107 /** 108 * Clears all the Class to Transformer mappings. 109 */ 110 public void clear() { 111 map.clear(); 112 } 113 114 /** 115 * Returns the Set of Classes used as keys in the map. 116 * @return Set of Classes 117 */ 118 public Set<Class<?>> classes() { 119 return map.keySet(); 120 } 121 122 /** 123 * Returns the Set of NumberTransformers used as values 124 * in the map. 125 * @return Set of NumberTransformers 126 */ 127 public Collection<NumberTransformer> transformers() { 128 return map.values(); 129 } 130 131 /** 132 * Attempts to transform the Object against the map of 133 * NumberTransformers. Otherwise it returns Double.NaN. 134 * 135 * @param o the Object to be transformed. 136 * @return the double value of the Object. 137 * @throws MathIllegalArgumentException if the Object can not be 138 * transformed into a Double. 139 * @see org.apache.commons.math3.util.NumberTransformer#transform(java.lang.Object) 140 */ 141 public double transform(Object o) throws MathIllegalArgumentException { 142 double value = Double.NaN; 143 144 if (o instanceof Number || o instanceof String) { 145 value = defaultTransformer.transform(o); 146 } else { 147 NumberTransformer trans = getTransformer(o.getClass()); 148 if (trans != null) { 149 value = trans.transform(o); 150 } 151 } 152 153 return value; 154 } 155 156 /** {@inheritDoc} */ 157 @Override 158 public boolean equals(Object other) { 159 if (this == other) { 160 return true; 161 } 162 if (other instanceof TransformerMap) { 163 TransformerMap rhs = (TransformerMap) other; 164 if (! defaultTransformer.equals(rhs.defaultTransformer)) { 165 return false; 166 } 167 if (map.size() != rhs.map.size()) { 168 return false; 169 } 170 for (Map.Entry<Class<?>, NumberTransformer> entry : map.entrySet()) { 171 if (! entry.getValue().equals(rhs.map.get(entry.getKey()))) { 172 return false; 173 } 174 } 175 return true; 176 } 177 return false; 178 } 179 180 /** {@inheritDoc} */ 181 @Override 182 public int hashCode() { 183 int hash = defaultTransformer.hashCode(); 184 for (NumberTransformer t : map.values()) { 185 hash = hash * 31 + t.hashCode(); 186 } 187 return hash; 188 } 189 190 }