[Java] 取多个时间段内的重叠时间部分 日期类型使用yyyyMMddHHmmss的Long类型（20220513104000）

流程/思路：

package controller;

import java.util.*;
import java.util.stream.Collectors;

public class TestController {

    /**
     * @param unusableTimeList 所有时间段：[startTime, endTime, startTime, endTime, startTime, endTime]
     * @return 返回时间段：[startTime, endTime, startTime, endTime]
     */
    public static List<Long> getOverlapTimeRange(List<Long> unusableTimeList) {
        List<Long> finalUnusableTimeList = new ArrayList<>();
        // 统计时间段，去重
        Map<List<Long>, Integer> timeRangeMap = new HashMap<>();
        // 获取每段时间的时间点，去重
        Set<Long> timeSet = new HashSet<>(unusableTimeList);
        // 将Set转换为List, 并排序
        List<Long> newUnusableTimeList = new ArrayList<>(timeSet).stream().sorted(Long::compareTo).collect(Collectors.toList());
        // 统计每段时间的重复次数
        Map<String, Integer> timeRangeReserCountMap = new HashMap<>();
        for (int i = 0; i < newUnusableTimeList.size(); i++) {
            if (i + 1 == newUnusableTimeList.size()) break;
            // 每段时间的间隔
            Long startInt = newUnusableTimeList.get(i);
            Long endInt = newUnusableTimeList.get(i + 1);
            String key = startInt + "_" + endInt;
            // 每段时间的重复次数
            Integer timeRangeCount = timeRangeReserCountMap.get(key) != null ? timeRangeReserCountMap.get(key) : 0;
            //迭代每段时间范围，算出每子时间段内的重复时间占用数量
            for (int j = 0; j < unusableTimeList.size(); j = j + 2) {
                if (j + 1 == unusableTimeList.size()) break;
                //预约开始结束范围
                Long reserStartInt = unusableTimeList.get(j);
                Long reserEndInt = unusableTimeList.get(j + 1);
                if (reserStartInt <= startInt && endInt <= reserEndInt) {
                    timeRangeCount++;
                }
                if (timeRangeReserCountMap.get(key) != null && timeRangeReserCountMap.get(key) > 1) { // 判断该时间段是否达到某种需求条件,这里为时间段重复次数大于1的就返回
                    timeRangeMap.put(Arrays.asList(startInt, endInt), timeRangeCount);
                }
                timeRangeReserCountMap.put(key, timeRangeCount);
            }
        }
        for (Map.Entry<List<Long>, Integer> entry : timeRangeMap.entrySet()) {
            finalUnusableTimeList.addAll(entry.getKey());
        }
        return finalUnusableTimeList;
    }

    public static void main(String[] args) {
        List<Long> unusableTimeList = new ArrayList<>();
        unusableTimeList.add(20200513000000L);
        unusableTimeList.add(20200513235959L);
        unusableTimeList.add(20200513120000L);
        unusableTimeList.add(20200513235959L);
        unusableTimeList.add(20200513101010L);
        unusableTimeList.add(20200513111111L);
        unusableTimeList.add(20200513131313L);
        unusableTimeList.add(20200513151515L);
        List<Long> overlapTimeRange = getOverlapTimeRange(unusableTimeList);
        System.out.println(overlapTimeRange);

    }
}