作者：

出处：

客户端：

import java.net.DatagramPacket;

import java.net.DatagramSocket;

import java.net.InetAddress;

import java.net.SocketException;

import java.net.UnknownHostException;

import java.io.IOException;

public class UdpClient {

    public static void main(String arg[]) {

        String outstr;

        if(arg.length >= 1)

            outstr = arg[0];

        else

            outstr = "count";

        try {

            DatagramSocket socket = new DatagramSocket();

            byte outblock[] = outstr.getBytes();

            InetAddress address = InetAddress.getLocalHost();

            DatagramPacket outpacket =

                    new DatagramPacket(outblock,outblock.length,address,8765);

            socket.send(outpacket);

            System.out.println("Client sent: " + outstr);

            byte inblock[] = new byte[256];

            DatagramPacket inpacket =

                    new DatagramPacket(inblock,inblock.length);

            socket.receive(inpacket);

            String instr = new String(inpacket.getData(),0,inpacket.getLength());

            System.out.println("Client got: " + instr);

            socket.close();

        } catch(SocketException e) {

            System.out.println(e);

        } catch(UnknownHostException e) {

            System.out.println(e);

        } catch(IOException e) {

            System.out.println(e);

        }

    }

}

服务器端：

import java.net.DatagramSocket;

import java.net.DatagramPacket;

import java.net.InetAddress;

import java.io.IOException;

import java.util.Date;

public class UdpServer {

    public static void main(String arg[]) {

        DatagramSocket socket = null;

        int count = 0;

        try {

            socket = new DatagramSocket(8765);

        } catch(IOException e) {

            System.out.println(e);

        }

        while(true) {

            try {

                byte block[] = new byte[256];

                DatagramPacket inpacket

                        = new DatagramPacket(block,block.length);

socket.receive(inpacket);

                int length = inpacket.getLength();

                System.out.println("Length of the data received: " + length);

   byte inblock[] = inpacket.getData();

                String inmsg = new String(inblock,0,length);

                System.out.println("Server got: " + inmsg);

                count++;

                String outmsg;

                if(inmsg.equals("date")) {

                    Date date = new Date();

                    outmsg = date.toString();

                } else if(inmsg.equals("halt")) {

                    socket.close();

                    return;

                } else if(inmsg.equals("count")) {

                    outmsg = "Number of messages: " + count;

                } else {

                    outmsg = "What is " + inmsg + "?";

                }

                byte outblock[] = outmsg.getBytes();

                InetAddress returnaddress = inpacket.getAddress();

                int returnport = inpacket.getPort();

                DatagramPacket outpacket = new DatagramPacket(

                        outblock,outblock.length,returnaddress,returnport);

                socket.send(outpacket);

            } catch (IOException e) {

                e.printStackTrace();

            }

        }

    }

}

 

作者：

出处：