Currently we handle out of memory once the error has already occurred. This in most case affects the responsiveness of the application and error messages are not readily available to the user. Instead of this approach we should be able to warn the user when the user is critically low on memory. We could achieve this with help of MemoryMXBean which of part of JDK 1.5 or above.

See some useful snippets of OutOfMemoryError Warning System here,

http://www.javaspecialists.eu/archive/Issue092.html

http://www.javalobby.org/forums/thread.jspa?messageID=91821553