Head First Java, 2nd Edition

Chapter 16. Collections and Generics: Data structures

Sorting is a snap in Java. You have all the tools for collecting and manipulating your data without having to write your own sort algorithms (unless you’re reading this right now sitting in your Computer Science 101 class, in which case, trust us—you are SO going to be writing sort code while the rest of us just call a method in the Java API). The Java Collections Framework has a data structure that should work for virtually anything you’ll ever need to do. Want to keep a list that you can easily keep adding to? Want to find something by name? Want to create a list that automatically takes out all the duplicates? Sort your co-workers by the number of times they’ve stabbed you in the back? Sort your pets by number of tricks learned? It’s all here...

Tracking song popularity on your jukebox

Congratulations on your new job—managing the automated jukebox system at Lou’s Diner. There’s no Java inside the jukebox itself, but each time someone plays a song, the song data is appended to a simple text file.

Your job is to manage the data to track song popularity, generate reports, and manipulate the playlists. You’re not writing the entire app—some of the other software developer/ waiters are involved as well, but you’re responsible for managing ...