Given an ip in a numeric, string format, return the InetAddress. - Java Network

Java examples for Network:IP Address

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Description

Given an ip in a numeric, string format, return the InetAddress.

Demo Code


//package com.java2s;
import java.net.InetAddress;
import java.net.UnknownHostException;

public class Main {
    public static void main(String[] argv) throws Exception {
        String ip = "java2s.com";
        System.out.println(parseNumericIp(ip));
    }//w ww  . j a v  a 2s  .  co  m

    /**
     * Given an ip in a numeric, string format, return the InetAddress.
     * @param ip the ip address in string format (such as 3232235780)
     * @return the InetAddress object (such as the object representing 192.168.1.4)
     */
    public static InetAddress parseNumericIp(String ip) {
        return parseNumericIp(Long.parseLong(ip));
    }

    /**
     * Given an ip in numeric format, return the InetAddress.
     * @param ip the ip address in long (such as 3232235780)
     * @return the InetAddress object (such as the object representing 192.168.1.4)
     */
    public static InetAddress parseNumericIp(long ip) {
        try {
            return InetAddress.getByAddress(numericIpToByteArray(ip));
        } catch (UnknownHostException e) {
            return null;
        }
    }

    /**
     * Given an ip in numeric format, return a byte array that can be fed to
     * InetAddress.
     * @param ip the ip address in long (such as 3232235780)
     * @return the byte array.
     */
    public static byte[] numericIpToByteArray(long ip) {
        byte[] ipArray = new byte[4];
        ipArray[3] = (byte) (ip & 0xff);
        ipArray[2] = (byte) ((ip >> 8) & 0xff);
        ipArray[1] = (byte) ((ip >> 16) & 0xff);
        ipArray[0] = (byte) ((ip >> 24) & 0xff);
        return ipArray;
    }
}

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