Forcing deallocation of large cache object in Java

Question

I use a large (millions) entries hashmap to cache values needed by an algorithm, the key is a combination of two objects as a long. Since it grows continuously (because keys in

Answer 1

Clear the hashmap:

hashmap.clear();

Then force a garbage collector run:

Runtime.getRuntime().gc();

This is the Javadoc page for Runtime.gc().