Java Animated Maze Generator and Solver

In preparation for showing off the maze-navigating robot I made last week, I give you this program I wrote last year.

When I started to learn Java, I wrote this little program for practice. It features a GUI and multi-threading. It generates a maze and then slowly solves the maze so you can watch it go. I wrote this with the GNU project’s Java implementation (never used the official Sun one). The Makefile is therefore set up for gcj and gij. The Makefile can build the byte-compiled .jar file as well as a natively compiled version. I have updated it to use Ant, and I also use Sun’s OpenJDK these days.

The maze generation algorithm is what I believe to be called the “straw man” algorithm: the maze starts as a matrix of individual cells. Break down the walls between two cells that aren’t already connected and move into it. Choose another wall at random and repeat. If there are no walls left to break down, go back a step. Lather, rinse, repeat. If you are back in the starting cell with no more walls to break down, you are done.

Solving the maze is done in a similar way to generation. Go forward, right, or left if you can. If not, go back to the previous cell. This is the same algorithm I employed in the maze-navigating robot I built, which has kept me pretty busy. I will post pictures of it later.

You can specify the maze height, width, and cell pixel size on the command line when you run it. This runs with the defaults,

java -jar RunMaze.jar

Or if you grabbed the source,

ant run

And, for a tiny 100 by 100 maze,

java -jar RunMaze.jar 100 100 5


java -jar RunMaze.jar <width> <height> <cell-size>

So, why learn Java? I still don’t like Java, but I had missed out on an interesting research opportunity because I had zero Java experience. I probably wouldn’t use it on my own for anything but practice, as my own projects don’t really need to be super-portable. Java is ugly, bulky, and slow, but I don’t want to miss any more opportunities. Right after I was turned down because of my lack of experience, I bought a Java textbook and read it cover to cover on vacation. More importantly, I wrote simple little Java programs (like the one presented here) as I learned core concepts.

Update 2009-07-07: I use Java all the time at work now. There is really no escaping it. Except maybe with something like Clojure

Have a comment on this article? Start a discussion in my public inbox by sending an email to ~skeeto/ [mailing list etiquette] , or see existing discussions.

This post has archived comments.

null program

Chris Wellons (PGP)
~skeeto/ (view)