Recently I had to figure out a way to add undo/redo functionality to an existing Java application. Searching the web for some guidance I got a bit scared by finding posts that gave the impression that undo in Java is an overly complex thing that requires 10+ mysterious classes, best combined with reflection and modified GoF patterns.
I write this post to show you how simple undo in Java is and how it can be easily added to an existing application. You do not need to study Command patterns or rebuild half of your app, just follow the pragmatic approach described below and add a few simple classes to your application!
In our concrete case the requirement was to add undo functionality to an existing Excel-like spreadsheet application that had a horrible menu management and no patterns in it at all. Continue reading “Add Undo/Redo functionality to a Java app” »