Get the remote address using ServletRequest.getRemoteAddr()

Sunday, June 25. 2006

Get the remote address using ServletRequest.getRemoteAddr()

Only when configuring Apache Web Server Plug-In for WebLogic, I happened to know that the API getRemoteAddr in Servlet Spec by design is not necessarily return the source client IP, as stated in the SDK:

String getRemoteAddr()

Returns the Internet Protocol (IP) address of the client or last proxy that sent the request. For HTTP servlets, same as the value of the CGI variable REMOTE_ADDR.

Returns:
a String containing the IP address of the client that sent the request

Beware of the "last proxy", which in this context it is the Apache Web server, so should we assume we could always obtain the source client IP address by calling getRemoteAddr? Should we assume there is always configuration we can make on the App server so that there will be additional parameter (like WL-Proxy-Client-IP for this case) added into the HTTP header?
If we should not, what would be the better way to get the client IP address? Or, should we get the client IP after all?

Something else about the getRemoteAddr puzzled me when I was studying the API doc: since it states that it will always return the IP (Internet Protocol) address, why would it return String instead of InetAddress object?

Posted by Steven Yong in computer at 14:15 | Comment (1) | Trackbacks (0)

...

Trackbacks

Trackback specific URI for this entry

No Trackbacks

Comments

Display comments as (Linear | Threaded)

Talk about being "lazy". Returning a String object for multi-purpose use, i.e. if you need an InetAddress object, just "create on the fly"??

I read the bug description and it says that, "the intention was to be like what CGI does, and that's string based.", so, does that mean that the team building the SDK was emulating what existing capabilities CGI has only?

They probably took the easy way out to give a generic object such as String back so that they need not write additional methods to return an InetAddress object when it probably wasn't needed in the first place. That's because they "assume" that the developer would use the java.net API to get the InetAddress object when required.

Hmmm.. Just wondering, if the API code will use the InetAddress.toString() method in the getRemoteAddr() method??

#1 Angie Tan (Homepage) on 2006-06-26 11:20 (Reply)

Add Comment