我有很多看起来像这样的文件。
{
"_id" : ObjectId("5bcf7d670a31a41b382823e2"),
"score" : 75
}
我的后端语言是java。 我使用_id字段按日期过滤数据。
我有一个Java方法,该方法提供了有关时区的Object_id。
public static ObjectId getObjectId(String date, String fromTimeZone) {
SimpleDateFormat formatterFrom = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
formatterFrom.setTimeZone(TimeZone.getTimeZone(fromTimeZone));
return new ObjectId(Long.toHexString(formatterFrom.parse(date).getTime() / 1000L) + "0000000000000000");
}
fromTimeZone可能类似于。
GMT+08:00
UTC
Africa/Algiers
Europe/London etc.
现在,我想在应用程序仪表板上添加一些图表。所以我需要最近7天这样的数据。
{date: Nov-01, score:75}
{date: Nov-02, score:75}
{date: Nov-03, score:75}
{date: Nov-04, score:75}
{date: Nov-05, score:75}
{date: Nov-06, score:75}
{date: Nov-07, score:75}
由于许多用户使用不同的时区,所以我真的不知道该怎么做。
请帮助。
答案 0 :(得分:1)
您只需要获取匹配的文档,按时区按日期分组,对分数求和并输出文档。
获取并格式化结果
//Create Variables
String endDt = "2018-11-08 01:02:03";
String startDt = "2018-11-01 01:02:03";
String timeZone = "GMT+08:00";
//Query Filter
Bson query = Aggregates.match(Filters.and(
Filters.lte("_id", getObjectId(endDt,timeZone)),
Filters.gte("_id", getObjectId(startDt,timeZone ))
));
//Objectid to datetime expression
Document toDate = new Document("$toDate", "$_id");
Bson objectIdToDate = Aggregates.projection(Projections.fields(
Projections.excludeId(),
Projections.include("score"),
Projections.computed("date", toDate)
));
//Date expression with timezone
Document dateExpression = Document.parse(
"{'$dateFromParts':{
'year':{'$year':{'date':'$date','timezone:'"+ timeZone +"}},
'month':{'$month':{'date':'$date','timezone':"+ timeZone +"}},
'day':{'$dayOfMonth':{'date':'$date','timezone':"+ timeZone +"}}
}}"
);
//Group by Date
Bson group = Aggregates.group(new Document("$_id", dateExpression), Accumlators.sum("score", "$score"));
//final output
Bson fields = Aggregates.projection(Projections.fields(
Projections.excludeId(),
Projections.include("score"),
Projections.computed("date", "$_id")
));
//Fetch matching records
AggregateIterable<Document> iterable = collection.aggregate(Arrays.asList(query,objectIdToDate,group,fields));
//Format results
for(Document document:iterable) {
document.put("date", formatDateToMonthDay(date));
}
辅助方法
public static String formatDateToMonthDay(Date date) {
DateTimeFormattter monthDayFormatter = DateTimeFormatter.ofPattern("MMM-dd");
Instant instant = date.toInstant();
return instant.format(monthDayFormatter);
}
public ObjectId getObjectId(String date, String fromTimeZone) {
DateTimeFormattter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
LocalDateTime localDateTime = LocalDateTime.parse(date,formatter);
Instant instant = LocalDateTime.ofInstant(instant, ZoneId.of(fromTimeZone)).toInstant();
return new ObjectId(Long.toHexString(instant.getEpochSecond()) + "0000000000000000");
}