calculating client IP address

[Lowell Kirsh]

I want to create a link that a user can click which will create a popup
telling the user their ip address. I have:

var ip = new java.net.InetAddress.getLocalHost().toString();
alert("Your IP address is: " + ip.substring(ip.indexOf("/")+1))

but this does not seem to work. It says the ip is 127.0.0.1. Strangely,
this piece of code used to work but all of a sudden it doesn't for some
unknown reason. Can anyone tell me what's wrong with the above code?

Lowell

[Evertjan.]

Lowell Kirsh wrote on 21 aug 2004 in comp.lang.javascript:

I want to create a link that a user can click which will create a popup
telling the user their ip address. I have:
If it does not direct to a[nother] page it is not a link
var ip = new java.net.InetAddress.getLocalHost().toString();
alert("Your IP address is: " + ip.substring(ip.indexOf("/")+1))
What scriptlanguage/platform are you using ["new java.net"?]?
Surely not clientside javascript with DOM [=wisdom?] ?
but this does not seem to work. It says the ip is 127.0.0.1. Strangely,
this piece of code used to work but all of a sudden it doesn't for some
unknown reason. Can anyone tell me what's wrong with the above code?

We would first have to know the above.
--
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)

[Michael Winter]

On 21 Aug 2004 07:41:23 GMT, Evertjan. <ex**************@interxnl.net>
wrote:

Lowell Kirsh wrote on 21 aug 2004 in comp.lang.javascript:

[snip]

var ip = new java.net.InetAddress.getLocalHost().toString();
alert("Your IP address is: " + ip.substring(ip.indexOf("/")+1))

What scriptlanguage/platform are you using ["new java.net"?]?
Surely not clientside javascript with DOM [=wisdom?] ?

It's Java (the networking package) being called from JavaScript. Opera and
IE don't seem to support that (if they do, a different syntax is required).

but this does not seem to work. It says the ip is 127.0.0.1. Strangely,
this piece of code used to work but all of a sudden it doesn't for some
unknown reason. Can anyone tell me what's wrong with the above code?

Whilst this would be more appropriate in a Java group, you're here now.

If you look at the description of the getLocalHost() method, you'll see:

If there is a security manager, its checkConnect method is called
with the local host name and -1 as its arguments to see if the
operation is allowed. If the operation is not allowed, an
InetAddress representing the loopback address is returned.

Java running under JavaScript will be using a security manager and, I
should imagine, a very restricted one at that. Whilst the code worked
running on my machine (using only Mozilla and Netscape, I might add), I
doubt that it will work from a remote host. In that case, as it states
above, you'll have the loopback address returned.

In other words: it a security thing that you can do nothing about.

Mike

--
Michael Winter
Replace ".invalid" with ".uk" to reply by e-mail.

[Andrew Thompson]

On Sat, 21 Aug 2004 08:14:10 GMT, Michael Winter wrote:

Java running under JavaScript will be using a security manager and, I
should imagine, a very restricted one at that.

Java run under the control of JS is actually subjected
to a more strict security environment than are regular
applets. Im afraid I have few further details, but am
amazed the OP could ever get any access to the user's IP
address using Java in an applet (let alone one operated
via JS) ..reaks of the MSVM to me..

If that is the case 'used to worki n IE', my only advice
to the OP is 'get used to *not* being able to do that'..

The MSVM is no longer supported by MS, and there are
various utilities on 'the market' for ridding one's
Windows of this insecure pretence for Java.

--
Andrew Thompson
http://www.PhySci.org/ Open-source software suite
http://www.PhySci.org/codes/ Web & IT Help
http://www.1point1C.org/ Science & Technology