擷取IP地址

參考CORE JAVA。

在JAVA中，InetAddress類用於操作與IP地址相關的內容，常用方法如下：

java.net.InetAddress 1.0• static InetAddress getByName(String host)• static InetAddress[] getAllByName(String host)constructs an InetAddress, or an array of all Internetaddresses, for the given host name.• static InetAddress getLocalHost()constructs an InetAddress for the local host.• byte[] getAddress()returns an array of bytes that contains thenumerical address.• String getHostAddress()returns a string with decimal numbers,separated by periods, for example "132.163.4.102".• String getHostName()returns the host name.

 

package com.lujinhong.corejava;import java.net.InetAddress;import java.net.UnknownHostException;public class InetAddressTest {    public static void main(String[] args) {        try {// Get the first argument as the hostname.            if (args.length > 0) {                InetAddress[] inetAddresses = InetAddress.getAllByName(args[0]);                for(InetAddress ia : inetAddresses){                    System.out.println(ia);                }            }else{//if No argument, get the localhost ip address.                InetAddress localHostAddress = InetAddress.getLocalHost();                System.out.println(localHostAddress);                System.out.println(localHostAddress);            }        } catch (UnknownHostException e) {            e.printStackTrace();        }    }}