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Java program to perform garbage collection

Java program to perform garbage collection: Free memory in Java virtual machine is printed and then garbage collection is done using gc method of RunTime class, freeMemory method returns the amount of free memory in JVM, getRunTime method is used to get reference of current RunTime object.

Java programming source code

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());
   }
}

Download Garbage collection program class file.

Output of program:
Output of Java program for garbage collection

Obviously, the amount of available memory after garbage collection will be different on your computer. Numbers are not important, what is important is that the mount of memory available is more after garbage collection than before. You can use this code in your program or projects which uses large amount of memory or where new objects are created frequently but required for a short span of time.