按日期分组

Aggregation aggregation2 = Aggregation.newAggregation(
        Aggregation.match(Criteria.where("type").is(VisitRecordByDay.TYPE_SHOW_WEI_BASE_VISIT)),
        Aggregation.group().sum("time").as("count")
);

/**
 * 获取指定时间段的数据，按日期统计数量
 *
 * @param field          按数据库中哪个字段统计
 * @param startTimestamp 开始时间戳
 * @param endTimestamp   结束时间戳
 * @param format         格式化时间，%Y-%m-%d 按天，%Y-%m 按月
 * @return List<CountVo>
 */
public List<CountVo> getListDate(String field, Date startTimestamp, Date endTimestamp, String format, String collectionName, Criteria criteria) {
    Aggregation aggregation = Aggregation.newAggregation(
            Aggregation.match(Criteria.where(field).gte(startTimestamp).lt(endTimestamp).andOperator(criteria)),
            Aggregation.project(field).and(DateOperators.DateToString.dateOf(field).toString(format)).as("date"),
            Aggregation.group("date").count().as("count"),
            Aggregation.project("date", "count").and("date").previousOperation(),
            Aggregation.sort(Sort.Direction.ASC, "date")
    );
    return mongoTemplate.aggregate(aggregation, collectionName, CountVo.class).getMappedResults();
}

/**
 * 获取指定时间段的数据，按某字段数量和统计
 */
public List<CountVo> getListDateForSum(String field, Date startTimestamp, Date endTimestamp, String format, String collectionName, Criteria criteria, String sumFieldName) {
    Aggregation aggregation = Aggregation.newAggregation(
            Aggregation.match(Criteria.where(field).gte(startTimestamp).lt(endTimestamp).andOperator(criteria)),
            Aggregation.project(field, sumFieldName).and(DateOperators.DateToString.dateOf(field).toString(format)).as("date"),
            Aggregation.group("date").count().as("count2").sum(sumFieldName).as("count"),
            Aggregation.project("date", "count").and("date").previousOperation(),
            Aggregation.sort(Sort.Direction.ASC, "date")
    );
    return mongoTemplate.aggregate(aggregation, collectionName, CountVo.class).getMappedResults();
}

时区差8小时

根据时间统计会出现

Aggregation.project().andExpression("add(createTime," + 8 * 60 * 60 * 1000 + ")").as("newDate")

统计表中所有数据某字段相加

Aggregation.group().sum("time").as("count")

日期补全

使用的是hutool工具包做底层支持

/**
 * 补全一个月的所有天
 *
 * @param dateList       原数据
 * @param startTimestamp 开始时间戳
 * @param endTimestamp   结束时间戳
 * @return List<CountVo>
 */
private List<CountVo> supplementMonth(List<CountVo> dateList, long startTimestamp, long endTimestamp) {
    // 今日之后不显示
    if (endTimestamp > new Date().getTime()) {
        endTimestamp = new Date().getTime();
    }
    long stride = 24 * 60 * 60 * 1000; // 步长
    ArrayList<CountVo> listDate = new ArrayList<>();
    for (long newTime = startTimestamp; newTime <= endTimestamp; newTime += stride) {
        String formatDate = DateUtil.format(new Date(newTime), "yyyy-MM-dd");
        boolean isFind = false;
        for (CountVo countVo : dateList) {
            if (formatDate.equals(countVo.getDate())) {
                listDate.add(countVo);
                isFind = true;
                break;
            }
        }
        if (!isFind) {
            listDate.add(new CountVo(formatDate, 0L));
        }
    }
    return listDate;
}


/**
 * 补全一年的所有月份
 *
 * @param dateList  原数据
 * @param startDate 一年开始时间
 * @return List<CountVo>
 */
private List<CountVo> supplementYear(List<CountVo> dateList, Date startDate) {
    ArrayList<CountVo> listDate = new ArrayList<>();
    for (int i = 0; i < 12; i++) {
        Date monthDate = DateUtil.offsetMonth(startDate, i);
        // 本月之后不显示
        if (monthDate.getTime() > new Date().getTime()) {
            break;
        }
        String formatDate = DateUtil.format(monthDate, "yyyy-MM");
        boolean isFind = false;
        for (CountVo countVo : dateList) {
            if (formatDate.equals(countVo.getDate())) {
                listDate.add(countVo);
                isFind = true;
                break;
            }
        }
        if (!isFind) {
            listDate.add(new CountVo(formatDate, 0L));
        }
    }
    return listDate;
}

日期补全CountVo

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@NoArgsConstructor
@AllArgsConstructor
public class CountVo {

    private String date;
    private long count;
    
}