Last days, I was working on a project which needs big heap size.And i always have the following exception
"main" java.lang.OutOfMemoryError: Java heap space
I found that the default java heap size is : 128MB , so my application need more about 1GP !!.
So the solution was to make it larger using the following command :

java -Xms<initial heap size> -Xmx<maximum heap size>

like
java -Xms32m -Xmx128m

in netBeans you can change your project heap size from Project Properties :

In netBeans,Open the configuration file etc/netbeans.conf(In netBeans installed directory) and modify the #netbeans_default_options="-J-Xmx128m to -J-Xmx96m and -J-XX:MaxPermSize=96m to -J-XX:MaxPermSize=64m". This way also we have to increase the Heap size.

Thank you so much for this addition

Just what I was looking for! cheers.

Thank you ....
you saved my app.. :-)

thank you for gave me some knowledge about this topic.

To be precise,

(Java 1.1)
java -ms32m -mx128m MyClassName

(Java 1.2 / 2.0)
java -Xms32m -Xmx128m MyClassName


'X' indicates that these are non-standard options that might not function the same way in future JVMs.