扫描端口

扫描端口

import java.net.*;
import java.io.*;

public class PortScan {
    public static void main(String[] args) {
        String host = "localhost";
        if (args.length > 0) {
            host = args[0];
        }
        // 扫描端口号小于1024的端口
        for (int i = 1; i < 1024; i++) {
            try {
                Socket s = new Socket(host, i);
                System.out.println("There is a server on port " + i + " of "
                        + host);
            } catch (UnknownHostException e) {
                System.err.println(e);
                break;
            } catch (IOException e) {
            }
        }
    }
}