根据java面向对象的原理，ip地址也被封装成了对象，InetAdress

import java.net.InetAddress;import java.net.UnknownHostException;import java.util.Arrays;import org.junit.Test;/** * 获取ip地址 * @author WangShuang * */public class Demo {    @Test    public void run1() {        try {            //获取本机的ip地址            InetAddress localHost = InetAddress.getLocalHost();            System.out.println(localHost);            //已知别人的域名 获取别人的ip地址对象            InetAddress byName = InetAddress.getByName("www.baidu.com");            System.out.println(byName);            String hostAddress = byName.getHostAddress();//返回ip地址的字符串表现形式            System.out.println(hostAddress);            InetAddress[] allByName = InetAddress.getAllByName("www.baidu.com");            System.out.println(Arrays.toString(allByName));        } catch (UnknownHostException e) {            e.printStackTrace();        }    }}