JavaRanch uses a Java program to pick the weekly winners for book promotions.  It previously used a serious of classes that went the URLs, parsed the data, went to more URLs, picked some random winners and then output them to a file.  These contortions were done because the old software was hard to change.  With the new Java based software, we have much more active development.  Time for a new approach.

Designing the new pick winners program.  (It’s the 3rd iteration of the program and the 2nd I’ve done so I’m familiar with the domain.)

1. Decide to make a web based version (servlet)
2. Think about what I need from the database.
3. Write three DAO methods to get post, topic and user info.  While I wrote the integration tests first, I did write the unit tests after the code.
4. Start the pick winner class  Realize there is a lot of date validation logic (and determining the default week) and rename class to WinnerPickingWeek to encapsulate the date range.
5. Start the pick winner class again.  Call the three DAO methods tying them together.
6. Now add the randomness.  My test with 1 post will give me enough determinism to keep the tests passing and useful.
7. Added a test for excluding ineligible winners (like Henry and I – the winner pickers)
8. Now on to the front end.  My servlet needs to make sure you are logged in as admin and then delegate to the processing logic.

This got a useable program that runs much faster.  After that I added some jQuery logic to make the page dynamic and even more useful.  But that’s another topic – possibly a more interesting one.  I’ll post it later in the week.