TCP：TCP通信协议是一种可靠的网络协议，它在通信的两端各建立一个Socket对象

在通信之前一定要保证通信已经建立

通过Socket产生IO流来进行网络通信

package Day18_net;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.ServerSocket;
import java.net.Socket;

public class NetTest05 {
    public static void main(String[] args) throws IOException {
        //接收端
        //1、创建sercerSocket
        ServerSocket ss = new ServerSocket(10086);
        //2、监听客户端的链接
        Socket accept = ss.accept();
        //3、从链接通道中获取
        InputStream is = accept.getInputStream();
        //将字节流变为字符流
        InputStreamReader isr = new InputStreamReader(is);
        //添加缓冲流
        BufferedReader br = new BufferedReader(isr);

        int b;
        while ((b = br.read()) != -1) {
            System.out.print((char) b);
        }
        //4、
        accept.close();
        ss.close();

    }
}

package Day18_net;

import java.io.IOException;
import java.io.OutputStream;
import java.net.Socket;
import java.nio.charset.StandardCharsets;

public class NetTest04 {
    public static void main(String[] args) throws IOException {
        //发送端
        //1、创建Socket对象
        Socket socket = new Socket("127.0.0.1",10086);
        //2、可以从链接通道中获取输出流
        OutputStream os = socket.getOutputStream();
        //3、写出数据
        os.write("你好".getBytes("UTF-8"));
        //4、释放资源
        os.close();
        socket.close();
    }
}

TCP协议中的三次握手和四次挥手协议：