telnet time-a.nist.gov 13

telnet horstmann.com 80

GET / HTTP/1.1
Host:horstmann.com
blank line

public class Test1 {
    public static void main(String[] args) {
        /*創(chuàng)建一個指定地址和端口的套接字，如果創(chuàng)建失敗會拋出一個UnknownHostException*/
        try (Socket s = new Socket("time-a.nist.gov",13);
             Scanner in = new Scanner(s.getInputStream(),"utf-8")
             ){
            while (in.hasNextLine()){
                String line = in.nextLine();
                System.out.println(line);
            }
        }catch (IOException e) {
            /*如果存在host 不存在之外的異常會拋出一個IOException 異常
            * UnknownHostException是這個異常的子異常
            * */
            e.printStackTrace();
        }
    }
}

Socket s = new Socket(...);
s.setTimeout(10000);

Socket s =new Socket();
s.connect(new InetSocketAddress(host,port),timeout)

public class Test1 {
    public static void main(String[] args) throws UnknownHostException {
        String host = "www.baidu.com";
        /*InetAddress address = InetAddress.getByAddress(host);*/
        /*
        一般的域名只會對應一個一個IP地址
        而一些訪問量比較大的域名會對應多個IP地址，從而實現(xiàn)負載均衡
        可以通過上面的方法獲取一個IP地址
        也可以通過下面的方法獲取一個域名對應的多個IP地址
         */
        /*InetAddress 的toString方法會會返回一個字符串類型，進而打印會輸出對應的ip地址*/
        InetAddress[] addresses = InetAddress.getAllByName(host);
        for (InetAddress address : addresses){
            System.out.println(address);
        }
    }
}

    public static void main(String[] args) throws UnknownHostException {
        InetAddress address = InetAddress.getLocalHost();
        System.out.println(address);
    }

Socket(String host,int port)

InputStream getInputStream()
OutputStream getOutputStream()

void connect(SocketAddress address)

void connect(SocketAddress address,int timeout)

void setTimeout(int timeout)

boolean isConnected()

boolean isClosed()

statci InetAddress getByName(String host)
statci InetAddress[] getAllByName(String host)

static InetAddress getLocalHost()

byte[] getAddress()

String getHostAddress()

String getHostName()