Re: Ping from JAVA to IP Address

From:

Robert Klemme <shortcutter@googlemail.com>

Newsgroups:

comp.lang.java.programmer

Date:

Mon, 24 Oct 2011 20:26:22 +0200

Message-ID:

<9gloupFf3oU1@mid.individual.net>

On 24.10.2011 20:01, sahm wrote:

I'm tiring to ping to External IP address (e.x : www.google.com) but I
keep get false every time.
I write function to do the ping. I can ping to local IP address fine,
but when I try to ping any external IP (e.x. www.google.com) it wont
work I keep get false.
this is my code

Does a command line ping work? If not you cannot expect it to work from
Java. There might be firewalls in between blocking ICMP.

============ start ===============
package netscan;

import java.io.IOException;
import java.net.InetAddress;
import java.net.UnknownHostException;

public class NetPing
{
     boolean reach = false;
     public boolean pinging()
     {
         try
         {
             InetAddress address =
InetAddress.getByName("www.google.com");
             reach =address.isReachable(60000);

AFAIK there is no guarantee that isReachable() does a ping:
http://download.oracle.com/javase/6/docs/api/java/net/InetAddress.html#isReachable(int)

             System.out.println(String.valueOf(reach));

         }
         catch(UnknownHostException uhe)
         {
             System.out.println(uhe.toString());
         }
         catch(IOException io)
         {
             System.out.println(io.toString());
         }
         catch(Exception e)
         {
             System.out.println(e.toString());
         }

         return reach;
     }

}
============ end ===============

Kind regards

robert

--
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/