001    /*
002     * Copyright 2002-2007 the original author or authors.
003     * 
004     * Licensed under the Apache License, Version 2.0 (the "License"); you may not
005     * use this file except in compliance with the License. You may obtain a copy of
006     * the License at
007     * 
008     * http://www.apache.org/licenses/LICENSE-2.0
009     * 
010     * Unless required by applicable law or agreed to in writing, software
011     * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
012     * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
013     * License for the specific language governing permissions and limitations under
014     * the License.
015     */
016    package org.springframework.rules.support;
017    
018    import java.util.Comparator;
019    
020    /**
021     * Comparator for comparing Number instances.
022     * <p>
023     * Uses the double value of the number to do the actual comparison
024     * 
025     * @author Peter De Bruycker
026     */
027    public class NumberComparator implements Comparator {
028    
029            public static final NumberComparator INSTANCE = new NumberComparator();
030            
031            private NumberComparator() {
032                    // singleton
033            }
034            
035            public int compare(Object o1, Object o2) {
036                    Number n1 = (Number) o1;
037                    Number n2 = (Number) o2;
038    
039                    return Double.compare(n1.doubleValue(), n2.doubleValue());
040            }
041    }