转自http://blog.yesky.com/Blog/tot/archive/2005/03/28/96525.html
jdk设置:
1.建立 JAVA_HOME install dir
2.path加上 %JAVA_HOME%\bin;
3.classpath 加上 .;%JAVA_HOME%\lib\tools.jar;%JAVA_HOME%\lib\dt.jar
使用:j2sdk1.4.2_09 在教育网的http://www.zusky.com/soft/ 自由天空下载
/*
* 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: whandey@163.com
*
* 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 = "202.205.3.143";
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 = 75;nport < 85;++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){}

}
}