1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one 3 * or more contributor license agreements. See the NOTICE file 4 * distributed with this work for additional information 5 * regarding copyright ownership. The ASF licenses this file 6 * to you under the Apache License, Version 2.0 (the 7 * "License"); you may not use this file except in compliance 8 * with the License. You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, 13 * software distributed under the License is distributed on an 14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 15 * KIND, either express or implied. See the License for the 16 * specific language governing permissions and limitations 17 * under the License. 18 * 19 */ 20 package org.apache.directory.mavibot.btree.comparator; 21 22 23 import java.util.Comparator; 24 25 26 /** 27 * Compares integers 28 * 29 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> 30 */ 31 public class IntComparator implements Comparator<Integer> 32 { 33 /** A static instance of a IntComparator */ 34 public static final IntComparator INSTANCE = new IntComparator(); 35 36 /** 37 * A private constructor of the IntComparator class 38 */ 39 private IntComparator() 40 { 41 } 42 43 44 /** 45 * Compare two integers. 46 * 47 * @param integer1 First integer 48 * @param integer2 Second integer 49 * @return 1 if integer1 > integer2, 0 if integer1 == integer2, -1 if integer1 < integer2 50 */ 51 public int compare( Integer integer1, Integer integer2 ) 52 { 53 if ( integer1 == integer2 ) 54 { 55 return 0; 56 } 57 58 if ( integer1 == null ) 59 { 60 if ( integer2 == null ) 61 { 62 return 0; 63 } 64 else 65 { 66 return -1; 67 } 68 } 69 else 70 { 71 if ( integer2 == null ) 72 { 73 return 1; 74 } 75 else 76 { 77 return integer1.compareTo( integer2 ); 78 } 79 } 80 } 81 }