ExpiredWindow.java

package com.netease.youdata.util;

import java.util.concurrent.ConcurrentHashMap;

public class ExpiredWindow<K, V> {

    private Long windowSize;

    private ConcurrentHashMap<K, V> dataMap = new ConcurrentHashMap<>();

    private ConcurrentHashMap<K, Long> timeMap = new ConcurrentHashMap<>();

    private Thread cleanupThread() {
        return new Thread(() -> {
            while (true) {
                timeMap.forEach((k, remain) -> {
                    if (remain == 0) {
                        timeMap.remove(k);
                        dataMap.remove(k);
                        System.out.println("clean " + k);
                    } else {
                        timeMap.put(k, remain - 1);
                    }
                });
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }, "clean thread");
    }

    public V get(K key) {
        return dataMap.getOrDefault(key, null);
    }

    public void put(K key, V value) {
        dataMap.put(key, value);
        timeMap.put(key, windowSize);
    }

    public ExpiredWindow(Long seconds) {
        windowSize = seconds;
        cleanupThread().start();
    }
}