[网络协议]Java 基础练习（十七）使用Tcp与Udp实现简单通信

1、通信软件的功能

有客户端和服务器端，实现客户端和服务器相互不停的发送和接收消息。
要求发送和接收消息可以同时进行。

使用tcp实现

//-- 读取数据类
import java.io.IOException;
import java.io.InputStream;
import java.net.Socket;

public class ReadData extends  Thread {

    private Socket socket;

    public ReadData(Socket socket){
        this.socket=socket;
    }

    @Override
    public void run() {
        super.run();
        InputStream inputStream=null;
            try {
                inputStream = socket.getInputStream();
                byte[] bytes = new byte[1024];
                int read = inputStream.read(bytes);
                while (read!=-1){
                    System.out.println(new String(bytes,0,read));
                    read=inputStream.read(bytes);
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
    }
}

//-- 写数据类
import java.io.IOException;
import java.io.OutputStream;
import java.net.Socket;
import java.util.Scanner;

public class WriteData extends  Thread {
    private Socket socket;

    public  WriteData(Socket socket){
        this.socket=socket;
    }

    @Override
    public void run() {
        super.run();
        OutputStream outputStream =null;
        while (true){
            Scanner scanner = new Scanner(System.in);
            String s=scanner.nextLine();
            try {
                outputStream = socket.getOutputStream();
                outputStream.write(s.getBytes());
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

    }
}
//-- 我作为客户端
import java.io.IOException;
import java.net.Socket;

public class My {
    public static void main(String[] args) throws IOException {
        Socket socket = new Socket("localhost", 9000);
        new WriteData(socket).start();
        new ReadData(socket).start();
    }
}
//-- 你作为服务端
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;

// 一个作为服务器，一个作为客户端
//服务器中可以读写，但是在一个线程中会read与scanner会相互阻塞，将两个阻塞分开到两个线程中即可
public class You {
    public static void main(String[] args) throws IOException {
        ServerSocket serverSocket = new ServerSocket(9000);

        //向下转型，在设计类时寻找相同点作为属性，子类没有相同点，可向上转型呢？面向对象
        Socket accept = serverSocket.accept();

        new ReadData(accept).start();
        new WriteData(accept).start();

    }

使用Udp实现

//-- 我作为客户端发送消息
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.util.Scanner;


public class My implements Runnable {

    private int dkh;

    public My(int dkh){
        this.dkh=dkh;
    }

    @Override
    public void run() {

        while (true) {

            udpMy();

        }

    }

    void udpMy() {
        DatagramSocket datagramSocket = null;

        DatagramPacket datagramPacket = null;

        try {
            datagramSocket = new DatagramSocket();
            Scanner scanner = new Scanner(System.in);
            String s = scanner.next();
            byte[] bytes = s.getBytes();//一次全部接受发送,不必固定字节数组的长度
            InetAddress locahost = InetAddress.getByName("localhost");
            datagramPacket = new DatagramPacket(bytes, 0, bytes.length, locahost, dkh);
            datagramSocket.send(datagramPacket);

        } catch (Exception e) {

        } finally {

        }


    }
}
//-- 你作为服务端接受消息
package ParcticeDiwuzhou.lx0813.lx.udptx;

import java.net.DatagramPacket;
import java.net.DatagramSocket;


public class You implements Runnable {
//    private Lock lock;
//
//    public You(Lock lock){
//        this.lock=lock;
//    }

    private int dkh;

    public You(int dkh){
        this.dkh=dkh;
    }

    @Override
    public void run() {

        while (true) {

            udpYou();

        }

    }
    void udpYou() {

        DatagramSocket datagramSocket = null;
        DatagramPacket datagramPacket = null;

        try {

            datagramSocket = new DatagramSocket(dkh);
            byte[] bytes = new byte[1024];
            datagramPacket = new DatagramPacket(bytes, 0, bytes.length);
            datagramSocket.receive(datagramPacket);
            System.out.print("You:");
            System.out.println(new String(bytes));

        } catch (Exception e) {

        } finally {

        }
    }

}
//-- 开启两个线程我和你可以是客户端的同时也是服务端
public class MyMianThread {
    public static void main(String[] args) {
        Lock lock=new ReentrantLock();

        My my = new My(9600);
        Thread thread = new Thread(my);
        thread.start();

        You you = new You(9601);
        Thread thread1 = new Thread(you);
        thread1.start();

    }
}
//-- You
public class YouMianThread {
    public static void main(String[] args) {
        Lock lock=new ReentrantLock();

        You you = new You(9600);
        Thread thread1 = new Thread(you);
        thread1.start();


        My my = new My(9601);
        Thread thread = new Thread(my);
        thread.start();
    }
}