单机延迟队列（环形数组）

单机版延迟队列，适用业务中，X秒/分钟/小时后执行的业务场景，此方案的弊端完全在内存，机器异常重启后数据丢失，优势轻量

1,目前支持到秒级别，若有毫秒级，需要自己修改timeLoop()方法中的睡眠时间；

2,线程池参数threadPoolInit()，根据自己的业务场景进行调整;

import lombok.extern.slf4j.Slf4j;

import java.util.ArrayList;
import java.util.Collection;
import java.util.LinkedList;
import java.util.List;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.function.Consumer;
import java.util.stream.Collectors;


@Slf4j
public class DelayCycleBuffer {

    
    private final List> cycleDataList;

    
    private final AtomicInteger clock = new AtomicInteger(0);

    
    private ThreadPoolExecutor threadPoolExecutor;

    
    private void threadPoolInit() {
        threadPoolExecutor = new ThreadPoolExecutor(32, 64, 10, TimeUnit.SECONDS, new LinkedBlockingQueue<>(100000), run -> new Thread(run, "CONSUME-THREAD-" + run.hashCode()));
    }


    
    private final int capacity;

    
    private final AtomicInteger size = new AtomicInteger(0);

    
    public DelayCycleBuffer(int capacity, Consumer> callBack) {
        if (capacity < 0) {
            throw new IllegalArgumentException("capacity must >=0");
        }
        cycleDataList = new CopyOnWriteArrayList<>();
        //初始化
        for (int i = 0; i < capacity; i++) {
            cycleDataList.add(new CycleData<>());
        }
        this.capacity = capacity;
        //线程池初始化
        this.threadPoolInit();
        //开启时间轮询1s一次
        this.timeLoop(callBack);
    }

    
    public void put(T t, Integer second) {
        if (t == null || second == null || second < 0) {
            throw new IllegalArgumentException("param is valid~!");
        }
        int currentClock = clock.get();
        int nextClock = currentClock + 1 + second;
        DataInfo data = new DataInfo<>();
        data.setCircle(nextClock / capacity);
        data.setData(t);

        int index = nextClock % capacity;
        CycleData tCycleData = this.cycleDataList.get(index);
        tCycleData.dataInfoList.add(data);
        size.incrementAndGet();
    }

    
    public Collection takeData(int clockTime) {
        log.info("------exec ---{}s", clockTime);
        Collection result = new ArrayList<>();
        CycleData tCycleData = cycleDataList.get(clockTime);
        //过滤出，不是当前圈的数据 ，并且将符合条件的数据，放入result中
        List> dataInfoList = tCycleData.getDataInfoList().stream().filter(m -> {
            if (m.getCircle() > 0) {
                m.setCircle(m.getCircle() - 1);
                return true;
            }
            result.add(m.getData());
            size.decrementAndGet();
            return false;
        }).collect(Collectors.toList());
        tCycleData.setDataInfoList(dataInfoList);
        return result;
    }

    
    private void timeLoop(Consumer> callBack) {
        Thread thread = new Thread(() -> {
            log.info("-------------time loop is started~!----");
            while (true) {
                try {
                    int clockTime = clock.getAndIncrement();
                    threadPoolExecutor.submit(() -> {
                        Collection ts = takeData(clockTime);
                        callBack.accept(ts);
                    });
                    int currClock = clock.get();
                    if (currClock == capacity) {
                        clock.compareAndSet(currClock, 0);
                    }
                    TimeUnit.MILLISECONDS.sleep(1000L);
                } catch (Exception e) {
                    log.error("exception~!", e);
                }
            }
        }, "TimeLoop-Thread");
        thread.setDaemon(true);
        thread.start();
    }

    public int getSize() {
        return size.get();
    }

    public static class CycleData {
        private List> dataInfoList = new LinkedList<>();

        public List> getDataInfoList() {
            return dataInfoList;
        }

        public void setDataInfoList(List> dataInfoList) {
            this.dataInfoList = dataInfoList;
        }
    }

  
    public static class DataInfo {
        private Integer circle = 0;

        
        private T data;

        public Integer getCircle() {
            return circle;
        }

        public void setCircle(Integer circle) {
            this.circle = circle;
        }

        public T getData() {
            return data;
        }

        public void setData(T data) {
            this.data = data;
        }
    }

}

单元测试：

import lombok.extern.slf4j.Slf4j;
import org.springframework.util.CollectionUtils;

import java.util.Random;
import java.util.concurrent.TimeUnit;

@Slf4j
public class DelayCycleBufferTest {

    public static void main(String[] args) throws InterruptedException {
        //初始化，并申明消费方法
        DelayCycleBuffer delayCycleBuffer = new DelayCycleBuffer<>(3600, dataList -> {
            if (CollectionUtils.isEmpty(dataList)) {
                return;
            }
            //直接做打印
            log.info("get data from rang buff size :{}", dataList.size());
        });
        
        //模拟存放数据
        Random random = new Random();
        new Thread(()->{
            for (int i = 0; i < 20000; i++) {
                delayCycleBuffer.put("数据"+i, random.nextInt(30));
            }
        }).start();
        
        //检查数量变化
        new Thread(()->{
            while (true){
                try{
                    log.info("剩余{}个", delayCycleBuffer.getSize());
                    TimeUnit.MILLISECONDS.sleep(1000L);
                }catch (Exception ignore){}
            }
        }).start();
        Thread.sleep(Integer.MAX_VALUE);
    }
}