How to deal with “java.lang.OutOfMemoryError: Java heap space” error?

Question

I am writing a client-side Swing application (graphical font designer) on Java 5. Recently, I am running into java.lang.OutOfMemoryEr

Answer 1

Big caveat ---- at my office, we were finding that (on some windows machines) we could not allocate more than 512m for Java heap. This turned out to be due to the Kaspersky anti-virus product installed on some of those machines. After uninstalling that AV product, we found we could allocate at least 1.6gb, i.e, -Xmx1600m (m is mandatory other wise it will lead to another error "Too small initial heap") works.

No idea if this happens with other AV products but presumably this is happening because the AV program is reserving a small block of memory in every address space, thereby preventing a single really large allocation.