Java利用Socket类实现TCP通信程序

public static void main(String[] args) throws UnknownHostException {
    // 获取本机的InetAddress对象
    InetAddress localHost = InetAddress.getLocalHost();
    System.out.println(localHost);
    // 根据本机的主机名获取InetAddress对象
    InetAddress host = InetAddress.getByName("DESKTOP-3G22U7M");
    System.out.println(host);
    // 根据域名获取InetAddress对象
    InetAddress host2 = InetAddress.getByName("www.baidu.com");
    System.out.println(host2);
    // 根据InetAddress对象获取ip地址
    String hostAddress = host2.getHostAddress();
    System.out.println(hostAddress);
    // 根据InetAddress对象获取主机名
    String hostName = host2.getHostName();
    System.out.println(hostName);
}

Socket client = new Socket("127.0.0.1", 6666);

ServerSocket server = new ServerSocket(6666);

public class ServerTCP {
    public static void main(String[] args) throws IOException {
    System.out.println("服务端启动 , 等待连接 .... ");
        // 1.创建 ServerSocket对象，绑定端口，开始等待连接
        ServerSocket ss = new ServerSocket(6666);
        // 2.接收连接 accept 方法, 返回 socket 对象.
        Socket server = ss.accept();
        // 3.通过socket 获取输入流
        InputStream is = server.getInputStream();
        // 4.一次性读取数据
        // 4.1 创建字节数组
        byte[] b = new byte[1024];
        // 4.2 据读取到字节数组中.
        int len = is.read(b)；
        // 4.3 解析数组,打印字符串信息
        String msg = new String(b, 0, len);
        System.out.println(msg);
        // =================回写数据=======================
        // 5. 通过 socket 获取输出流
        OutputStream out = server.getOutputStream();
        // 6. 回写数据
        out.write("我很好,谢谢你".getBytes());
        // 7.关闭资源.
        out.close();
        is.close();
        server.close();
    }
}

public class ClientTCP {
    public static void main(String[] args) throws Exception {
        System.out.println("客户端 发送数据");
        // 1.创建 Socket ( ip , port ) , 确定连接到哪里.
        Socket client = new Socket("localhost", 6666);
        // 2.通过Scoket,获取输出流对象 
        OutputStream os = client.getOutputStream();
        // 3.写出数据.
        os.write("你好么? tcp ,我来了".getBytes());
        // ==============解析回写=========================
        // 4. 通过Scoket,获取 输入流对象
        InputStream in = client.getInputStream();
        // 5. 读取数据数据
        byte[] b = new byte[100];
        int len = in.read(b);
        System.out.println(new String(b, 0, len));
    // 6. 关闭资源 .
       in.close();
        os.close();
        client.close();
    }
}