Accessing Apache's unique_id from Java code

Question

I need to access the mod_unique_id attribute for a request to my apache server. Is there a way to do that in the Java code, something like request.UNIQUE_ID?

I read through Environment Variables in Apache already and couldn't find anything, I also didn't entirely understand the article, so I may have missed something. If anyone could clear this up for me, that would be great!

Answer 1

You could add the UNIQUE_ID as a request header

Apache config:

    RequestHeader set UNIQUE_ID "%{UNIQUE_ID}e"

Then write some Java code to read this header:

    request.getHeader("UNIQUE_ID");

Answer 2

in /etc/apache2/apache2.conf:

<IfModule unique_id_module>
    SetEnvIf X-Requestid "^$" no_request_id
    RequestHeader set X-Requestid %{UNIQUE_ID}e env=no_request_id
</IfModule>

• add the symlink in modes-enabled:
  unique_id.load -> ../mods-available/unique_id.load
• in the shell, execute sudo a2enmod headers
• restart apache

in Java Code:

import javax.servlet.http.HttpServletRequest;
String uniqueId = request.getHeader("x-requestid");