import java.net.*;
import java.io.*;
public class DatagramReceiveDemo 
{	
	public static void main(String[] args) 
	{
		try
		{
			//聲明并創建DatagramSocket對象，并指定接收方程序接收數據端口為10745
			DatagramSocket receiveSocket = new DatagramSocket(10745);
	
			byte data[] = new byte[100];
			
			//創建接收數據包
			DatagramPacket receivePacket = new DatagramPacket(
					data,data.length);
			
			//利用循環監聽端口是否有客戶端發送的數據包
			while(true)
			{
				//接收數據報
				receiveSocket.receive(receivePacket);
				
				//獲取發送數據包的主機的地址
				String  sendIP = receivePacket.getAddress().toString();
				
				//獲取發送數據包的主機的端口號
				String sendPort = String.valueOf(receivePacket.getPort());
				String message = new String(receivePacket.getData(),0,receivePacket.getLength());
				
				//獲取發送數據包的內容
				System.out.println("Received data from:"+sendIP+":"+sendPort);
				System.out.println("Received data is:");
				System.out.println(message);
			}
		}
		catch(IOException e){e.printStackTrace();}		
	}
}