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.math.util; 019 020 import java.io.Serializable; 021 022 import org.apache.commons.math.MathException; 023 024 /** 025 * A Default NumberTransformer for java.lang.Numbers and Numeric Strings. This 026 * provides some simple conversion capabilities to turn any java.lang.Number 027 * into a primitive double or to turn a String representation of a Number into 028 * a double. 029 * 030 * @version $Revision: 800112 $ $Date: 2009-08-02 13:23:37 -0400 (Sun, 02 Aug 2009) $ 031 */ 032 public class DefaultTransformer implements NumberTransformer, Serializable { 033 034 /** Serializable version identifier */ 035 private static final long serialVersionUID = 4019938025047800455L; 036 037 /** 038 * @param o the object that gets transformed. 039 * @return a double primitive representation of the Object o. 040 * @throws org.apache.commons.math.MathException If it cannot successfully 041 * be transformed or is null. 042 * @see <a href="http://commons.apache.org/collections/api-release/org/apache/commons/collections/Transformer.html"/> 043 */ 044 public double transform(Object o) throws MathException{ 045 046 if (o == null) { 047 throw new MathException("Conversion Exception in Transformation, Object is null"); 048 } 049 050 if (o instanceof Number) { 051 return ((Number)o).doubleValue(); 052 } 053 054 try { 055 return Double.valueOf(o.toString()).doubleValue(); 056 } catch (Exception e) { 057 throw new MathException(e, 058 "Conversion Exception in Transformation: {0}", e.getMessage()); 059 } 060 } 061 062 /** {@inheritDoc} */ 063 @Override 064 public boolean equals(Object other) { 065 if (this == other) { 066 return true; 067 } 068 if (other == null) { 069 return false; 070 } 071 return other instanceof DefaultTransformer; 072 } 073 074 /** {@inheritDoc} */ 075 @Override 076 public int hashCode() { 077 // some arbitrary number ... 078 return 401993047; 079 } 080 081 }