端口扫描。
可以告诉你目标host下面的哪些端口在运行服务,目标host下有哪些闲置端口。
import java.io.IOException;
import java.net.Socket;
import java.net.UnknownHostException;
public class LowPortScanner {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
String host = "localhost";
if (args.length > 0)
{
host = args[0];
}
for (int i = 1; i < 10; i++)
{
try
{
Socket s = new Socket(host, i);
System.out.println("there is a server on port " + i + " of " + host);
}
catch (UnknownHostException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
System.err.println(e);
break;
}
catch (IOException e)
{
}
}
System.out.println("END.");
}
}