Compatibility of Java HTTP Api with Piwik 2.9.1

I am wanting to log usage of an application. however the app is servlet based and i dont have access to source code to change it. So my plan is to add a custom servlet to log to piwik, then chain back into regular app flow.
We are using Piwiki 2.9.1
What version of the Java HTTP API is compatible with this Piwik version?

The latest version of Java API should be compatible. If it isn’t, please report in the issue tracker of the java sdk