udpscan.java

精通Java核心技术源代码

// ==================== Program Discription =====================
// 程序名称：示例12-9: UDPScan.java
// 程序目的：熟悉DatagramSocket的基本用法，查询端口的占用情况。
//=========================================================
import java.net.*;

public class UDPScan
{
	  public static void main(String args[])
	  {
		for (int port=1024;port<=65535;port++) {
		   try {
		      DatagramSocket server=new DatagramSocket(port);
		      server.close();
		   }
		   catch(SocketException e) {
			 System.out.println("there is a server in port "+port+".");
		   }
     }
	 }
}