// source code developed by DevDaily Interactive, Inc.

public class GCTest {

   final int NELEMS = 50000;

   void eatMemory() {

      int[] intArray = new int[NELEMS];

      for (int i=0; i<NELEMS; i++) {
        intArray[i] = i;
      }

   }

   public static void main (String[] args) {

      GCTest gct = new GCTest();

      // Step 1: get a Runtime object
      Runtime r = Runtime.getRuntime();

      // Step 2: determine the current amount of free memory
      long freeMem = r.freeMemory();
      System.out.println("free memory before creating array: " + freeMem);

      // Step 3: consume some memory
      gct.eatMemory();

      // Step 4: determine amount of memory left after consumption
      freeMem = r.freeMemory();
      System.out.println("free memory after creating array:  " + freeMem);

      // Step 5: run the garbage collector, then check freeMemory
      r.gc();
      freeMem = r.freeMemory();
      System.out.println("free memory after running gc():    " + freeMem);

   }

}