As part of implementing the WhitestarMediaLibary project once it had been reviewed using SOLID principles, In this post I will cover adding a database interface and implementation.
The first thing that I realised when I came to implement the database interface is I had not considered the update and delete operators. This would be in keeping with the CRUD paradigm. Creating the interface was standard fare, as was moving the database parts of the WhitestarMusicLibrary to a new class DB40MusicDatabase.
Another item I noticed was missing from the design stage was exceptions so I created 2 exceptions: MediaNotFound and UnsupportedMedia. The class structure is now:
In addition to this a general search method has been added to the Database interface. This search method takes a predicate WhitestarMedia instead of using method overloading e.g search(String track), search(Date year) etc. The only issue this presents if one wanted to search for a date range. However at this stage I am trying to focus on structure (SOLID) and not creating functionality.
