How to get max heap size my java app is using?

Question

I'm running my Java app through command line without passing in any JVM settings (i.e. java -cp some.jar).

VisualVM shows the Java app allocated ~740M of Heap space.

Since I didn't pass in any JVM settings, how can I view what JVM settings my app is using?

Answer 1

You can use java.lang.management.MemoryUsage:

MemoryUsage mu = ManagementFactory.getMemoryMXBean().getHeapMemoryUsage();

and get max memory from it