The program can play 'mp3' and 'wav' files. It checks for validity of the files before adding them, makes sure the user can not add identical music files, performs additional other checks while active and outputs error and information windows to the user if needed. The program has over 1600 lines of code, demonstrates intermediate knowledge of Java, usage of functional programming, object-oriented programming, multithreading, integration of external libraries, database, and more.
