网络编程_UDP协议_聊天程序

发送端：（将数据源改为键盘录入）

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;

public class UDPSendDemo {
    public static void main(String[] args) throws IOException {

        System.out.println("发送端启动.......");

        //1.udp的socket服务，使用DatagramSocket对象
        DatagramSocket ds = new DatagramSocket();

        //2.将要发送的数据封装到数据包中
        //使用DatagramPacket将数据封装到该对象包中
        BufferedReader bufr = new BufferedReader(new InputStreamReader(System.in));

        String line = null;

        while((line = bufr.readLine())!=null){
            byte[] buf = line.getBytes();
            DatagramPacket dp = new DatagramPacket(buf, buf.length, InetAddress.getByName("127.0.0.1"), 10000);
            ds.send(dp);
            if("over".equals(line))
                break;
        }

        ds.close();

    }

}

接收端：

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;

public class UDPReceiveDemo {

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

        System.out.println("接收端启动.......");
            //1.建立udp socket服务
        DatagramSocket ds = new DatagramSocket(10000);
        while(true){
                //2.创建数据包
                byte[] buf = new byte[1024];
                DatagramPacket dp = new DatagramPacket(buf, buf.length);

                //3.使用接收方法将数据存储在数据包中
                ds.receive(dp);

                //4.通过数据包对象的方法，解析其中的数据，比如：地址，端口，数据内容
                String ip = dp.getAddress().getHostAddress();
                int port = dp.getPort();
                String text = new String(dp.getData(),0,dp.getLength());

                System.out.println(ip+":"+port+":"+text);
        }
        //5.关闭资源
        //ds.close();
    }

}

基于多线程的聊天程序：

Send.java

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;

public class Send implements Runnable {

    private DatagramSocket ds;

    public Send(DatagramSocket ds){
        this.ds = ds;
    }

    @Override
    public void run() {

        try {
            BufferedReader bufr = new BufferedReader(new InputStreamReader(System.in));
            String line = null;

            while((line=bufr.readLine())!=null){

                byte[] buf = line.getBytes();
                DatagramPacket dp =
                        new DatagramPacket(buf,buf.length,InetAddress.getByName("192.168.1.255"),10001);
                ds.send(dp);

                if("886".equals(line))
                    break;
            }

            ds.close();
        } catch (Exception e) {

        }
    }

}

Rece.java

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

public class Rece implements Runnable {

    private DatagramSocket ds;

    public Rece(DatagramSocket ds) {
        this.ds = ds;
    }

    @Override
    public void run() {
        try {
            while (true) {

                // 2,创建数据包。
                byte[] buf = new byte[1024];
                DatagramPacket dp = new DatagramPacket(buf, buf.length);

                // 3,使用接收方法将数据存储到数据包中。
                ds.receive(dp);// 阻塞式的。

                // 4，通过数据包对象的方法，解析其中的数据,比如，地址，端口，数据内容。
                String ip = dp.getAddress().getHostAddress();
                int port = dp.getPort();
                String text = new String(dp.getData(), 0, dp.getLength());

                System.out.println(ip + "::" + text);
                if(text.equals("886")){
                    System.out.println(ip+"....退出聊天室");
                }

            }
        } catch (Exception e) {

        }

    }

}

ChatDemo.java

import java.io.IOException;
import java.net.DatagramSocket;
import java.net.SocketException;

public class ChatDemo {

    /**
     * @param args
     * @throws IOException
     */
    public static void main(String[] args) throws IOException {

        DatagramSocket send = new DatagramSocket();

        DatagramSocket rece = new DatagramSocket(10001);
        new Thread(new Send(send)).start();
        new Thread(new Rece(rece)).start();

    }

}