How do I use Confluence's servlet-filter module?

Question

I have recently become aware of Confluence's servlet-filter module. However, after trying to get it to work, I have run into a dead end. I am getting my information here:

https://developer.atlassian.com/confdev/confluence-plugin-guide/confluence-plugin-module-types/servlet-filter-module

Here is what I tried. I annotated my atlassian-plugin.xml file like so:

<servlet-filter name="My Test Filter" key="OURAPP" class="com.test.filters.HelloWorldFilter" location="after-encoding" weight="100">
    <description>Forwards you to a test "Hello, world!" page.</description>
    <url-pattern>/helloworld</url-pattern>
    <dispatcher>REQUEST</dispatcher>
</servlet-filter>

Then, I created a standard Java servlet (extends HttpServlet, etc.) at com/test/filters called HelloWorldFilter.java. In the "doGet()" method, I simply have a System.out.println() line that reads "IN THE FILTER". However, when I go to the following URLs, I always get the "Page Not Found" error page:

http://127.0.0.1:8090/helloworld

http://127.0.0.1:8090/OURAPP/helloworld

http://127.0.0.1:8090/plugins/OURAPP/helloworld

http://127.0.0.1:8090/rest/helloworld

http://127.0.0.1:8090/rest/OURAPP/helloworld

http://127.0.0.1:8090/OURAPP/rest/helloworld

We have a custom Confluence plugin, lets call it OURAPP, that is serving up data not only through the browser GUI, but also through Confluence's REST capabilities. I am trying to create a filter that manages valid and invalid requests alike. We can access the REST at:

http://127.0.0.1:8090/rest/reststuff/v1/some_function_here

Like I said in the beginning, I have run into a dead end here, and cannot figure out how to get this to work. Can anybody offer up any suggestions or example code of how to get this working?

Answer 1

After a couple of days messing around with this, I FINALLY figured out what was wrong. I was extending javax.servlet.http.HttpServlet instead of implementing javax.servlet.Filter. After I changed to implementing Filter, and implemented all the proper methods, my servlet filter started to work at 127.0.0.1:8090/helloworld. There are a number of examples out there that use a standard Java Servlet (i.e., extending HttpServlet) but that [apparently] does not work with Confluence. I hope this helps somebody else out there struggling with Confluence's confusion. Thanks to all who took the time to read.