001// --------------------------------------------------------------------------------
002// Copyright 2002-2024 Echo Three, LLC
003//
004// Licensed under the Apache License, Version 2.0 (the "License");
005// you may not use this file except in compliance with the License.
006// You may obtain a copy of 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,
012// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013// See the License for the specific language governing permissions and
014// limitations under the License.
015// --------------------------------------------------------------------------------
016
017package com.echothree.util.common.string;
018
019public class Inet4AddressUtils {
020    
021    private Inet4AddressUtils() {
022        super();
023    }
024    
025    private static class Inet4AddressUtilsHolder {
026        static Inet4AddressUtils instance = new Inet4AddressUtils();
027    }
028    
029    public static Inet4AddressUtils getInstance() {
030        return Inet4AddressUtilsHolder.instance;
031    }
032    
033    // http://darksleep.com/player/JavaAndUnsignedTypes.html
034    public String formatInet4Address(Integer inet4Address) {
035        long rawInet4Address = inet4Address & 0xFFFFFFFFL;
036        int inet4Address0 = (int)(rawInet4Address & 0xFF);
037        int inet4Address1 = (int)((rawInet4Address & 0xFF00) >> 8);
038        int inet4Address2 = (int)((rawInet4Address & 0xFF0000) >> 16);
039        int inet4Address3 = (int)(rawInet4Address >> 24);
040        StringBuilder sb = new StringBuilder().append(inet4Address3).append('.').append(inet4Address2).append('.').
041                append(inet4Address1).append('.').append(inet4Address0);
042
043        return sb.toString();
044    }
045
046}