j_udpserver.java

一个十分好的java基础学习的课件

// ////////////////////////////////////////////////////////
// 
// J_UdpServer.java
// 
// Created by Jun-Hai Yong,    on XX xx, xxxx (Date)
// ////////////////////////////////////////////////////////
// Readme:
// A simple UDP example: server.
// ////////////////////////////////////////////////////////
// Using this example, please explicitly refer to the book:
//     Jun-Hai Yong. Programming in Java. 
//     Beijing: Tsinghua University Press, 2004.
// 使用本例子，请注明引用:
//     雍俊海. Java 程序设计. 北京: 清华大学出版社, 2004.
// Please note that the author and publisher make no 
// warranty of any kind on the examples provided.
// ////////////////////////////////////////////////////////

import java.net.*;
import java.io.*;
import java.util.Date;

public class J_UdpServer
{
    public static byte[] mb_getTime( )
    {
        Date d = new Date( );
        return d.toString( ).getBytes( );
    } // End of method: mb_getTime

    public static void main(String args[])
    {
        DatagramSocket dSocket;
        DatagramPacket inPacket;
        DatagramPacket outPacket;
        InetAddress    cAddr;
        int            cPort;
        byte[]         inBuffer= new byte[100];
        byte[]         outBuffer;
        String         s;

        try
        {
            dSocket = new DatagramSocket(8000);
            while (true)
            {
                inPacket= new DatagramPacket(inBuffer, inBuffer.length);
                dSocket.receive(inPacket);
                cAddr= inPacket.getAddress( );
                cPort= inPacket.getPort( );
                s= new String (inPacket.getData( ), 0, inPacket.getLength( ));
                System.out.println("Client Adr="+cAddr.getHostName( )+" at Port "+cPort+": "+s);

                outBuffer= mb_getTime( );
                outPacket= new DatagramPacket(outBuffer, outBuffer.length, cAddr, cPort);
                dSocket.send(outPacket);
            } // End of loop: while
        } // End of try
        catch (IOException e)
        {
            System.out.println("IOException occurred with socket.");
            System.out.println (e);
            e.printStackTrace( );
        } // End of try/structure
    } // End of method: main

} // End of class: J_UdpServer