怎么样扫描计算机系统本地和远程的端口,监测其是打开还是关闭的在很多应用程序中都要用到,下面是用java实现的简单的端口扫描程序。 Source Code: 
 
 /*  * Created on 2005-3-22  *  * TODO To change the template for this generated file go to  * Window - Preferences - Java - Code Style - Code Templates  */ /**  * @author whandey    connect to me: [email protected]  *  * TODO To change the template for this generated type comment go to  * Window - Preferences - Java - Code Style - Code Templates  */ import java.io.*; import java.net.*; import java.util.*;  public class SocketPort {
  public static void main(String[] args) {      String ip = "159.162.39.27";       String hostname = new String();          try{ //get the target ip address and hostname    InetAddress address = InetAddress.getByName(ip);    System.out.println(address);    hostname = address.getHostName();    System.out.println(hostname);    }    catch(UnknownHostException e)    {     System.out.println("Could not find "+ ip);          }         try   {   // creat the output file    PrintWriter fout = new PrintWriter( new FileWriter("PortInf.txt"));    fout.println("Information Of The Port On the " + hostname +"computer ");    fout.println();      // do ports scan   for(int nport = 25;nport < 30;++nport)   {    try   {        Socket s = new Socket(hostname,nport);    fout.println("The port " + nport + " is open!");        fout.println("Connected to "+ s.getInetAddress() + " on port " + s.getPort() + " from port "+ s.getLocalPort() + " of " + s.getLocalAddress());    //print the connected socket information    }        catch(IOException e)    {     fout.println("The port " + nport + " is closed!");     }       }   fout.close();      }   catch(IOException e){}     } }
 
   
 
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