There are multiple Java development environments on the current market, but very few of them are as easy to use as Greenfoot, a system based on objects specifically aimed at educational purposes.
The main ideal behind Greenfoot is to offer the user a graphical environment that includes animations and sounds as soon as you start using it. The only thing the user has to do is choose the objects that are going to be used and assign them the different actions that they have to fulfil.
Greenfoot uses a pre-established loop that orders each object to fulfil its action when the animation is activated, thus only requiring that the user establishes these actions and how the objects interact with one another.
An easy way to learn how to program in Java.
Furthermore, Greenfoot includes a very complete tutorial with which you'll be able to learn to use the program in very little time. Because it includes information to be able to advance step by step and thus understand how everything works.
Therefore, if you need a program that will help a group of students to start to program with objects or you simply feel like developing your own Java games, you have to download Greenfoot.