// 创建服务器端
    ServerSocket server = new ServerSocket(5555);

    while(true){
    // 等待连接
    Socket accept = server.accept();

    OutputStream outputStream = accept.getOutputStream();
    outputStream.write("你好，我是服务器！\r\n".getBytes());
    outputStream.flush();

    // 读取数据
    InputStream inputStream = accept.getInputStream();

    BufferedReader reader = new BufferedReader(new InputStreamReader(
        inputStream));
    System.out.println("服务器：" + reader.readLine());

     outputStream.close();
     inputStream.close();
    }

 //创建套接字 确定要连接的服务器ip与端口口
    Socket socket=new Socket("172.17.23.77",5555);


    InputStream inputStream = socket.getInputStream();
    BufferedReader br=new BufferedReader(new InputStreamReader(inputStream));
    String readLine = br.readLine();
    System.out.println("客户端："+readLine);

    //向服务器发送消息
    OutputStream outputStream = socket.getOutputStream();
    outputStream.write("你好\r\n".getBytes());
    outputStream.flush();

    outputStream.close();
    inputStream.close();