The Ironism

The Ironism

The lair of Lars J. Nilsson. Contains random musings on beer, writing and this thing we call life.

February 2010


A Google Analytics Plugin for Nexus


Note: this post is cross-posted on

Since Firebase Community Edition uses Maven heavily, I realized I’d like to track our Nexus repository in Google Analytics. The Nexus Book says that there exists such a plugin already, but apparently now one knows where it is. So here’s my attempt to write a simple one.

If you’re an impatient kind, here’s the source code.

I created the project  in Eclipse, instructions here.

Now, let’s start off with a “repository customizer” which is Nexus extension point we’ll use to insert a custom request processor into every repository…

Not too complicated. We’re using injection to get hold of the actual tracker components and we’re inserting it into all repostories.

Wait, all repositories? Yes, and it’s problem I haven’t really figured out yet. Ideally I’d like to track “hosted” repositories only. However, we’ve configured all our builds to use a few common development “groups” for convenience. However, Nexus seems to treat groups as first class members, so even though an artifact may be deployed in a hosted repository while accessed through a group, the request processor will not get notified for the hosted repository, only the group. I tend to see “groups” as equivalent to “views” in which case I’d expect the hosted repository to be called as well, but, no…

Now, let’s create a request processor which will react when someone “reads” a path in a repository.  We’ll take it in pieces…

We configure the plugin via system properties (not too beautiful, I know), the “tracker id” is the google tracking code id and is mandatory, and the “refer url” will be set on the call to GA if available.  We’re using the JGoogleAnalytics library to call GA for us. Also, I’m being naughty and throwing an illegal state exception if the tracker id is missing, since GA updates every 24 hours we’d like to be notified on errors early.

There’s  two methods above, one sets the logging in the tracker code to use to slf4j logger instead and the other checks for and sets the referer URL:

Not too complicated eh? The only thing to note is that the only way to set the refer URL is by creating a new URL building strategy. Well, I can live with that.

Before we go on we’ll create a small subclass on FocusPoint which we’ll use for tracking. Since JGoogleAnalitycs is made primarily for applications the focus point will URL encode itself, however, that won’t work for us, so we need to override it’s getContentURI method:

And finally we’ll tie it all toghether. We’ll react on “read” actions, create a URI (of form ‘//path’) and track asynchronously (which will spawn a new thread for calling GA:

And that’s it. It’s not perfect: though ideally I’d like to track hosted repositories only, I’d like to avoid tracking crawlers and I would prefer not to configure via system properties (hint for you Nexus bundle users out there, you can set system properties in the “conf/wrapper.conf” files), but I’ll leave those for a rainy day.

Here’s the source code as a Maven project.Enjoy!

Update: If you download and try to compile, you will probably be missing the JGoogleAnalytics lib. You’re welcome to use our, GA-tracked, repository if you like 🙂

The proprietor of this blog. Lunchtime poet, former opera singer, computer programmer. But not always in that order. Ask me again tomorrow.

    Comments 1
    • Shelley Wetzell
      Posted on

      Shelley Wetzell Shelley Wetzell


      It’s easier to keep out of the conversation and not take the chance of being misunderstood.