public class API_ {
    public static void main(String[] args) throws UnknownHostException {
        //獲取本機 InetAddress 對象 getLocalHost
        InetAddress localHost = InetAddress.getLocalHost();
        System.out.println(localHost);//LAPTOP-U9K8AF0S/172.21.202.203 獲取到主機的信息(主機名和ip地址)
        //根據指定主機名/域名獲取 ip 地址對象
        InetAddress host1 = InetAddress.getByName("LAPTOP-U9K8AF0S");//LAPTOP-U9K8AF0S主機名
        System.out.println(host1);//LAPTOP-U9K8AF0S/172.21.202.203,通過主機名來獲取到ip地址,當然這邊輸出的是主機名和ip地址
        System.out.println(host1.getHostAddress());//172.21.202.203,獲取到ip地址
        InetAddress host2 = InetAddress.getByName("www.baidu.com");//www.baidu.com域名
        System.out.println(host2);//www.baidu.com/153.3.238.102,通過域名來獲取ip地址,當然這邊輸出的是域名和ip地址
        System.out.println(host2.getHostAddress());//153.3.238.102,獲取ip地址
    }
}

package TEMP.Temp3;
//使用以上方法的小demo
import java.net.InetAddress;
import java.net.UnknownHostException;
public class InetAddressDemo {
    public static void main(String[] args) {
        try{
            //獲取自己本機地址信息
            InetAddress localIp=InetAddress.getLocalHost();
            //1獲取此IP地址的全限定域名
            System.out.println("1.localIp.getCanonicalHostName()="
                    + localIp.getCanonicalHostName());
            //2獲取該InetAddress對象對應的IP地址字符串
            System.out.println("2.localIp.getHostAddress()="
                    + localIp.getHostAddress());
            //3獲得該InetAddress對象的主機名稱
            System.out.println("3.localIp.getHostName()="
                    + localIp.getHostName());
            System.out.println("4.localIp.toString()="+localIp.toString());
            //5.判斷是否可以到達該地址
            System.out.println("5.localIp.isReachable(5000)="
                    + localIp.isReachable(5000));
            System.out.println("====================================");
            System.out.println("====================================");
            //獲取指定域名地址的信息([eg]百度）
            InetAddress baiduip = InetAddress.getByName("www.baidu.com");
            //1獲取此IP地址的全限定域名
            System.out.println("1.baiduIp.getCanonicalHostName()="
                    + baiduip.getCanonicalHostName());
            //2獲取該InetAddress對象對應的IP地址字符串
            System.out.println("2.baiduIp.getHostAddress()="
                    + baiduip.getHostAddress());
            //3獲得該InetAddress對象的主機名稱
            System.out.println("3.baiduIp.getHostName()="
                    + baiduip.getHostName());
            System.out.println("4.baiduIp.toString()="+baiduip.toString());
            //5判斷是否可以到達該地址
            System.out.println("5.baiduIp.isReachable(5000)="
                    + baiduip.isReachable(5000));
            System.out.println("====================================");
            System.out.println("====================================");
            //獲取指定原始IP地址信息
            InetAddress ip = InetAddress.getByAddress(new byte[]{127,0,0,1});
            // InetAddress ip = InetAddress.getByName("127.0.0.1");
            System.out.println("1.ip.getCanonicalHostName()=" + ip.getCanonicalHostName());
            System.out.println("2.ip.getHostAddress()= "+ ip.getHostAddress());
            System.out.println("3.ip.getHostName()="+ ip.getHostName());
            System.out.println("4.ip.toString()="+ ip.toString());
            System.out.println("5.ip.isReachable(5000)="
                    + ip.isReachable(5000));
        }catch(UnknownHostException e){
            e.printStackTrace();
        }catch(Exception e){
            e.printStackTrace();
        }
    }
}
//輸出結果
//        1.localIp.getCanonicalHostName()=shizhanli.lan
//        2.localIp.getHostAddress()=192.168.30.151
//        3.localIp.getHostName()=shizhanli
//        4.localIp.toString()=shizhanli/192.168.30.151
//        5.localIp.isReachable(5000)=true
//        ====================================
//        ====================================
//        1.baiduIp.getCanonicalHostName()=14.215.177.38
//        2.baiduIp.getHostAddress()=14.215.177.38
//        3.baiduIp.getHostName()=www.baidu.com
//        4.baiduIp.toString()=www.baidu.com/14.215.177.38
//        5.baiduIp.isReachable(5000)=true
//        ====================================
//        ====================================
//        1.ip.getCanonicalHostName()=localhost
//        2.ip.getHostAddress()= 127.0.0.1
//        3.ip.getHostName()=localhost
//        4.ip.toString()=localhost/127.0.0.1
//        5.ip.isReachable(5000)=true

package TEMP.Temp3;
//給定地址，找出主機名
import java.net.InetAddress;
import java.net.UnknownHostException;
public class ReverseTest {
    public static void main(String[] args) throws UnknownHostException {
        InetAddress ia = InetAddress.getByName("192.168.30.151");
        System.out.println(ia.getCanonicalHostName());
    }
}
//輸出結果：
//shizhanli.lan

package TEMP.Temp3;
//找到本地機器的IP地址
import java.net.InetAddress;
import java.net.UnknownHostException;
public class MyAddress {
    public static void main(String[] args) {
        try{
            InetAddress me = InetAddress.getLocalHost();
            String dottedQuad = me.getHostAddress();//創(chuàng)建一個String類型的變量來接受返回的ip地址
            System.out.println("My address is " + dottedQuad);
        }catch (UnknownHostException ex){
            System.out.println("I'm sorry.I don't know my own address.");
        }
    }
}
//輸出：My address is 192.168.30.151