Years ago, I used a program written in java, to run java code, and it showed the step-by-step execution, creating blocks of colors for every new object created or variables.

I do not remember the name, now giving course on java and want to show it to my students


  • Written in java
  • uses swing UI
  • Can run .java or .class files to show How are generated java objects, using colored blocks

The program that I mean, it was almost for children, built colored blocks with different data types (classes, primitive, constant, numbers , etc).

Each time an instruction is executed in Java was shown as an object built or variables are passed each other. This with an animation to highlight for a like variables are passed

Add a small demo done in Word


An alternative is welcome.

  • Are you wondering about an IDE (Integrated Development Environment)? – Zizouz212 Aug 21 '15 at 4:10

The builtin debugger of IntelliJ IDEA can do this, running a program step by step between arbitrary breakpoints that you defines.

You can also look at jdb, the standalone java debugger from oracle.

| improve this answer | |
  • 1
    IDEA is a good IDE, but, I need something else – jasilva Aug 21 '15 at 16:05


BlueJ is an IDE designed for people new to Java. It has features to assist the beginner.

Logo of BlueJ IDE

I've not used it. Just guessing that it might be the tool you remember.

They also offer a textbook, Objects First, designed for teaching newbies. Find more teacher resources on their web site. Look for BlueJ presentations and Birds of a Feather meetings at conferences.

| improve this answer | |

Would Eclipse work? It's an IDE written in SWT, and it's designed exactly for Java. You can find it at eclipse.org

I believe it is written in Java (Uses SWT, not Swing. It will be hard to find something advanced that uses Swing as many things have likely moved over to JavaFX). It also offers "toggles" and "breaks", allowing the code to stop executing when the runtime hits that section of code - It's intended for debugging actually, but it will work just as fine.

It does colour variables that are global or local, as well as the primitive data types. There's support for Strings, docs, and comments I believe as well. Here are some images:

  • General Development Environment:

    enter image description here

  • Code "Toggles" and "Breakpoints"

    enter image description here

| improve this answer | |
  • 1
    elicpse is a great IDE, I use daily, but not what I require – jasilva Aug 21 '15 at 19:25
  • @jasilva Then there really isn't anything that suits your requirements. – Zizouz212 Aug 21 '15 at 19:26
  • It exists, but can not remember his name, I get to use many years ago, it does not really have a lot of science, just run stepper each instrucion and draw colored blocks to represent the instructions. I do not remember if it was a jar, but the interface used swing (or awt, really do not remember) to represent the blocks – jasilva Aug 21 '15 at 19:31

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.