class test{ public static void main(String args[]) { Runtime r = Runtime.getRuntime(); long mem1, mem2; Integer someints[] = new Integer[1000]; System.out.println("Total memory is: " +r.totalMemory()); mem1 = r.freeMemory(); System.out.println("Initial free memory: " + mem1); r.gc(); mem1 = r.freeMemory(); System.out.println("Free memory after garbage collection: "+ mem1); for(int i=0; i<1000; i++) someints[i] = new Integer(i); // allocate integers mem2 = r.freeMemory(); System.out.println("Free memory after allocation: " + mem2); System.out.println("Memory used by allocation: "+ (mem1-mem2)); // discard Integers for(int i=0; i<1000; i++) someints[i] = null; r.gc(); // request garbage collection mem2 = r.freeMemory(); System.out.println("Free memory after collecting" +" discarded Integers: " + mem2); }} |
When run the code the output will be similar to this
Total memory is: 5177344
Initial free memory: 4986744
Free memory after garbage collection: 5063784
Free memory after allocation: 5045296
Memory used by allocation: 18488
Free memory after collecting discarded Integers: 5063784