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 */ 017 018 package org.apache.commons.math3.util; 019 020 import java.io.Serializable; 021 022 import org.apache.commons.math3.exception.util.LocalizedFormats; 023 import org.apache.commons.math3.exception.MathIllegalArgumentException; 024 import org.apache.commons.math3.exception.NullArgumentException; 025 026 /** 027 * A Default NumberTransformer for java.lang.Numbers and Numeric Strings. This 028 * provides some simple conversion capabilities to turn any java.lang.Number 029 * into a primitive double or to turn a String representation of a Number into 030 * a double. 031 * 032 * @version $Id: DefaultTransformer.java 1416643 2012-12-03 19:37:14Z tn $ 033 */ 034 public class DefaultTransformer implements NumberTransformer, Serializable { 035 036 /** Serializable version identifier */ 037 private static final long serialVersionUID = 4019938025047800455L; 038 039 /** 040 * @param o the object that gets transformed. 041 * @return a double primitive representation of the Object o. 042 * @throws NullArgumentException if Object <code>o</code> is {@code null}. 043 * @throws MathIllegalArgumentException if Object <code>o</code> 044 * cannot successfully be transformed 045 * @see <a href="http://commons.apache.org/collections/api-release/org/apache/commons/collections/Transformer.html">Commons Collections Transformer</a> 046 */ 047 public double transform(Object o) 048 throws NullArgumentException, MathIllegalArgumentException { 049 050 if (o == null) { 051 throw new NullArgumentException(LocalizedFormats.OBJECT_TRANSFORMATION); 052 } 053 054 if (o instanceof Number) { 055 return ((Number)o).doubleValue(); 056 } 057 058 try { 059 return Double.valueOf(o.toString()).doubleValue(); 060 } catch (NumberFormatException e) { 061 throw new MathIllegalArgumentException(LocalizedFormats.CANNOT_TRANSFORM_TO_DOUBLE, 062 o.toString()); 063 } 064 } 065 066 /** {@inheritDoc} */ 067 @Override 068 public boolean equals(Object other) { 069 if (this == other) { 070 return true; 071 } 072 return other instanceof DefaultTransformer; 073 } 074 075 /** {@inheritDoc} */ 076 @Override 077 public int hashCode() { 078 // some arbitrary number ... 079 return 401993047; 080 } 081 082 }