datagramreceivedemo.java

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import java.net.*;
import java.io.*;
public class DatagramReceiveDemo 
{	
	public static void main(String[] args) 
	{
		try
		{
			//声明并创建DatagramSocket对象，并指定接收方程序接收数据端口为10745
			DatagramSocket receiveSocket = new DatagramSocket(10745);
	
			byte data[] = new byte[100];
			
			//创建接收数据包
			DatagramPacket receivePacket = new DatagramPacket(
					data,data.length);
			
			//利用循环监听端口是否有客户端发送的数据包
			while(true)
			{
				//接收数据报
				receiveSocket.receive(receivePacket);
				
				//获取发送数据包的主机的地址
				String  sendIP = receivePacket.getAddress().toString();
				
				//获取发送数据包的主机的端口号
				String sendPort = String.valueOf(receivePacket.getPort());
				String message = new String(receivePacket.getData(),0,receivePacket.getLength());
				
				//获取发送数据包的内容
				System.out.println("Received data from:"+sendIP+":"+sendPort);
				System.out.println("Received data is:");
				System.out.println(message);
			}
		}
		catch(IOException e){e.printStackTrace();}		
	}
}