网络编程

1.如何定位一台主机？IP:端口，定位到计算机上的某个资源；

package com.langtao.Demo1;

import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.UnknownHostException;

public class Application {

public static void main(String[] args) throws UnknownHostException {

InetAddress inetAddress = InetAddress.getLocalHost();
System.out.println(inetAddress);

InetAddress address2 = InetAddress.getByName("www.baidu.com");
System.out.println(address2);

InetSocketAddress inetSocketAddress = new InetSocketAddress("www.sina.com", 8080);
System.out.println(inetSocketAddress);

}
}

2.如何传输数据？

2.1 TCP & UDP

TCP：面向连接，打电话（先接通，再通信）; 三次牵手，四次挥手；客户端/服务器
UDP：数据报协议，发短信（直接发信息）

2.2 TCP/IP协议簇