Issue #273: Caching Patterns [new pattern] - #277

• Put under review badge to the pull request
• Does the example code implement the pattern correctly and follow good coding practices?
• Does the example code have enough test coverage?
• Is the example code commented well enough?
• Is the example code following JavaDoc conventions?
• Are the project coding conventions being followed?
• Is the class diagram generated correctly?
• Is the index.md implemented correctly so the pattern will show correctly on the web site?

Remarks:

• There is an error in package declaration. The folder structure suggests package of com.wssia.caching but the declaration reads main.java.com.wssia.caching. For consistency I suggest you change the package to com.iluwatar.caching.
• There seems to be no main method in App. Is it intended to be run only through the JUnit tests? Please note that this is not consistent with the other examples.
• There is an option to use MongoDB as backend database. However, this is not enabled by default and instead in-memory data structure is used. Apparently MongoDB it is taken to use by setting the boolean flag in AppTest#setUp. I tried this and it seems to work.

@waisuan I'm done reviewing. Overall the implementation looks good. When you've implemented the changes please comment on this thread and I'll check again.

Hello @iluwatar. Thanks for the feedback. Kindly check the latest changes and let me know if there is anything else that I have missed out. Thanks.

P.S. And yes, I have left an option to use MongoDB as the backend DB as an alternative. Initially, I was testing with Mongo but it slipped my mind that this approach might cause the global maven compilation to fail when running the tests. So, I set the default DB to an internal structure instead to avoid said issue. Also, you're correct -- setting the flag in AppManager.initDB(boolean useMongoDB) allows the switching of the DBs. Hope that's alright. :)

P.P.S. I am not sure why the code coverage test failed. I did not make any major changes to the code. I looked at the details of the coverage test and there weren't any significant feedback on which modules/classes were causing the decrease in coverage. So...I'm uncertain as to whether my commit was the cause of the decrease or not. Do let me know if there is something I can do to fix this. Thanks.

Thank you very much for the valuable contribution!