像这种作业最好还是自己做

既然你也写了一个,那还是用你自己的最好,

努力吧

斑竹好强啊,呵呵,我都学了一个月了,连题目都看不懂 ,哎,我的努力啊.........白费了....................

哦!

不要哦啊
到底是什么问题啊

我也试了一下
客户端

import java.io.*;
import java.net.*;

public class UDPtest {
    public static void main(String []args){
        DatagramSocket dp = null;
        InetAddress address = null;
        DatagramPacket packet = null;
        if(args.length != 1) 
        {
            System.out.println(\"Please use the command java UDPtest <hostname>\"); return; }
        try {
             dp = new DatagramSocket();
        } catch (SocketException e) {
            System.out.println(\"打开端口失败\");
        }
        byte[] data = new byte[256];
        try {
            address = InetAddress.getByName(args [0]);
        } catch (UnknownHostException e) {
            System.out.println(\"没有找到对方主机\");
        }
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        try {
            data = br.readLine().getBytes();
            packet = new DatagramPacket (data, data.length, address, 5000);
            dp.send(packet); 
                packet = new DatagramPacket(data,data.length); 
                dp.receive(packet);
                String received = new String(packet.getData(),0,packet.getLength());
            while(!received.equals(\"bye\"))
            {
                System.out.println(received + \" from \"+address.getHostAddress()+\":\"+packet.getPort()); 
                data = br.readLine().getBytes();
                packet = new DatagramPacket (data, data.length, address, 5000);
                dp.send(packet);
                data = new byte[256];
                    packet = new DatagramPacket(data,data.length); 
                    dp.receive(packet);
                    received = new String(packet.getData(),0,packet.getLength()); 
            }
                
        } catch (IOException e) {
            e.printStackTrace();
        }
        dp.close(); 
    }
}

import java.io.*;
import java.net.*;

public class UDPserver {
    
    public static void main(String []args){
        DatagramSocket dp = null;
        DatagramPacket packet = null;
        try {
             dp = new DatagramSocket(5000);
        } catch (SocketException e) {
            System.out.println(\"打开端口失败\");
        }
        byte[] data = new byte[256];
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        try {
            packet = new DatagramPacket (data, data.length);
            dp.receive(packet); 
                String received = new String(packet.getData(),0,packet.getLength());
            while(!received.equals(\"bye\"))
            {
                InetAddress address = packet.getAddress();
                int port = packet.getPort();
                    System.out.println(received + \" from \"+address.getHostAddress()+\":\"+port);
                data = br.readLine().getBytes(); 
                    packet = new DatagramPacket(data,data.length,address,port); 
                    dp.send(packet);
                data = new byte[256];
                packet = new DatagramPacket (data, data.length);
                dp.receive(packet); 
                received = new String(packet.getData(),0,packet.getLength());
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        dp.close(); 
    }
}