You receive this message when compiling a code in Java:
Exception in thread "main" java.lang.OutOfMemoryError: Java heap space
When this exception occurs, it means that Java has run out of memory. If this code is still under development process, you should investigate for any memory leak issue. Or you could let Java to use more memory.
You can increase memory(heap size) by run java including these parameters:
-Xms[initial heap size] -Xmx[maximum heap size]
For example, set initial heap size to 128m and maximum to 256m.
java -Xms128m -Xmx256m
In NetBeans, simply goes to Project Properties –> Run.
Then you can add these parameters in VM Options.