Simple example of JVM GC usage

GC.java

import java.util.LinkedList;
import java.util.Queue;
import java.util.Scanner;

public class GC {
    
    private static Queue<Object> queue = new LinkedList<Object>();
    private static Scanner scanner = new Scanner(System.in); 
    
    public static void main(String...args) {
        while (true) {
            printCurrentState();
            printInvitation();
            processCommand();
        }
    }

    private static void printCurrentState() {
        print("Current number of objects is: " + queue.size());
    }
    
    private static void printInvitation() {
        print("Add or remove some objects. Use +/-N");
    }

    private static void processCommand() {
        int number = scanner.nextInt();
        
        if (number > 0) {
            increase(number);
        } else {
            decrease(Math.abs(number));
        }
    }
    
    private static void increase(int number) {
        for (int i = 0; i < number; i++) {
            queue.add(new Object());
        }
    }

    private static void decrease(int number) {
        for (int i = 0; i < number; i++) {
            queue.poll();
        }
    }

    private static void print(String message) {
        System.out.println(message);
    }
    
}