AutoPool.java

package com.cwidanage;

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

public class KryoTest {

    public static Queue<A> queue = new LinkedList<>();

    static class A {
        @Override
        protected void finalize() throws Throwable {
            // control how much we pool
            if (queue.size() < 1000) {
                queue.add(this);
            }
        }
    }

    static A instance() {
        if (queue.isEmpty()) {
            System.out.println("New");
            return new A();
        }
        System.out.println("Reuse");
        return queue.poll();
    }

    public static void main(String[] args) {


        new Thread(new Runnable() {
            @Override
            public void run() {
                while (true) {
                    System.gc();
                    try {
                        Thread.sleep(10000);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            }
        });

        while (true) {
            instance();
        }
    }
}