Java program using Garbage Collection

import java.util.*;
 
class GarbageCollection
{
   public static void main(String s[]) throws Exception
   {
      Runtime rs =  Runtime.getRuntime();
      System.out.println("Free memory in JVM before Garbage Collection = "+rs.freeMemory());
      rs.gc();
      System.out.println("Free memory in JVM after Garbage Collection = "+rs.freeMemory());
   }
}