Music playing

You shouldn't really get out of memory errors. This could either be a problem with Greenfoot/JDK, or an issue with the way you've programmed your scenario (e.g. keeping too many songs in memory). Could you share your scenario (probably without music tracks) or say a bit more about when the out of memory problems occur?

The out of memory problems occur usually after several compiles (I suspect mainly after editing my world class). I have put a lot of effort into graphics and sounds which I think is the main thing chewing up resources. If I post it so you can see it do you need the source code. I'm a bit hesitant about posting that as of yet.

This is one of the errors I get after compiling (sometimes) java.lang.OutOfMemoryError: Java heap space at java.awt.image.DataBufferInt.<init>(DataBufferInt.java:41) at java.awt.image.Raster.createPackedRaster(Raster.java:458) at java.awt.image.DirectColorModel.createCompatibleWritableRaster(DirectColorModel.java:1015) at java.awt.GraphicsConfiguration.createCompatibleImage(GraphicsConfiguration.java:163) at greenfoot.util.GraphicsUtilities.toCompatibleTranslucentImage(GraphicsUtilities.java:285) at greenfoot.util.GraphicsUtilities.loadCompatibleTranslucentImage(GraphicsUtilities.java:227) at greenfoot.GreenfootImage.loadURL(GreenfootImage.java:260) at greenfoot.GreenfootImage.loadFile(GreenfootImage.java:287) at greenfoot.GreenfootImage.<init>(GreenfootImage.java:109) at greenfoot.World.setBackground(World.java:195) at gameScreen.removeButtons(gameScreen.java:625) at gameScreen.addMainMenu(gameScreen.java:607) at gameScreen.<init>(gameScreen.java:144) at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27) at java.lang.reflect.Constructor.newInstance(Constructor.java:513) at greenfoot.core.Simulation.newInstance(Simulation.java:520) at greenfoot.platforms.ide.WorldHandlerDelegateIDE$3.run(WorldHandlerDelegateIDE.java:406) at greenfoot.core.Simulation.runQueuedTasks(Simulation.java:411) at greenfoot.core.Simulation.maybePause(Simulation.java:269) at greenfoot.core.Simulation.runContent(Simulation.java:201) at greenfoot.core.Simulation.run(Simulation.java:194)

That message is the world background tipping the memory use over the edge. But of course, it may be something else that is actually consuming the memory. There did used to be a JDK bug that would sometimes incorrectly retain the memory, but if you're doing a lot with images and sounds, that might be a likely candidate. If you're not happy about publishing the source code, you can alternatively email it to nccb@greenfoot.org so I can take a look to try to help.

I gave it a try, and I was able to reproduce the error if I reset a few times quite quickly. Your scenario is using quite a few images, but the problem is being exacerbated by some caching that Greenfoot is doing, which prevents garbage collection from clearing up the old images. We've added a fix to Greenfoot 2.2.0 (which should be out in the next few weeks) that should help alleviate the problem.