udpserver.java

TCP/IP服务器端与客户端 你可以通过此建立一个TCP服务端

import java.io.*;
import java.net.*;
class UDPServer 
{
	public static void main(String args[]) throws Exception
	{
		DatagramSocket serverSocket = new DatagramSocket(9876);
		byte[] receiveData = new byte[1024];
		byte[] sendData = new byte[1024];
		while(true)
		{
			DatagramPacket receivePacket =
			new DatagramPacket(receiveData, receiveData.length);
			serverSocket.receive(receivePacket);
			String sentence = new String(receivePacket.getData());
			InetAddress IPAddress = receivePacket.getAddress();
			int port = receivePacket.getPort();
			String capitalizedSentence = sentence.toUpperCase();
			sendData = capitalizedSentence.getBytes();
			DatagramPacket sendPacket =
			new DatagramPacket(sendData, sendData.length, IPAddress, port);
			serverSocket.send(sendPacket);
		}
	}
}