public class memorytest {
    public static void main(String[] args) {
        myClass test = new myClass();
        Thread thread = new Thread(test);
        thread.start();

    }
}

class myClass extends Thread {
    public void run() {
        try {
            Thread.sleep(10);
        } catch (InterruptedException e) {
                       e.printStackTrace();
        }
        while (true) {
            System.out.println(Runtime.getRuntime().freeMemory());
        }
    }

}