How to find the number of objects in the heap

Question

How can I find the number of live objects on the heap in Java program?

Answer 1

As far as I know, you cannot. You can, however, get the amount of memory used for the program:

 Runtime rt = Runtime.getRuntime();
 System.out.println("Used: " + (rt.totalMemory() - rt.freeMemory());
 System.out.println("Free: " + rt.freeMemory());
 System.out.println("Total: " + rt.totalMemory());