Trying to get request parameter out to access log in tomcat

Question

I trying to investigate how often a particular HTTP request is getting send to a web site. The request is a POST and has a parameter named "_method". I can see this in firebug getting net over.

I need to check the value of this "_method" parameter, so following the documentation http://tomcat.apache.org/tomcat-6.0-doc/config/valve.html#Access_Log_Valve I add the following to the tomcat access configuration for the valve

%{_method}r

But it is not coming out in access logs.

I wonder is that because of the underscore?

Note, the parameter name cannot be changed.

Kletter

Answer 1

OK, What I had to do was use the ExtendedAccessLogValve.

I added the below to my server.xml

    <Valve className="org.apache.catalina.valves.ExtendedAccessLogValve" directory="logs" pattern="c-dns x-H(remoteUser) date time cs-method cs-uri x-H(protocol) sc-status bytes x-P(_method)" prefix="localhost_extended_access_log." resolveHosts="false" suffix=".txt"/>

The part x-P(_method) is the crucial part which gave it to me.

I am including answer for any on-lookers.

Kletter

Answer 2

%{xxx}r 

is used for an "attribute in the ServletRequest" not for HTTP parameters (which are what I assume you mean, if you can see it in Firebug). ServletRequest attributes will be entirely server-side, so you would not be able to see them in Firebug.

If you want to output HTTP parameters (and it's not a GET, ie. they are in the URL) I think you would have to use Request Dumper Valve documented on that same page.

Difference between getAttribute() and getParameter() explains the difference if the above is not clear.

Number

Good point. Forgot about that. Think I need to use ExtendedAccessLogValve. Will test that and get it working and then post updated. – Kletter

Here's an example for anyone else having trouble with this: <Valve className="org.apache.catalina.valves.AccessLogValve" conditionIf="LogMe" directory="logs" prefix="localhost_access_log" suffix=".txt" pattern="%h %l %u %t &quot;%r&quot; %s %b,customAttribute: %{customAttribute}r" /> – Bauer