Spring MongoTemplate。排序在geo查询（NearQuery）中不工作

Question

Query query = new Query();
query.with(new Sort(Direction.DESC, "timeStamp"));
Criteria criteria = new Criteria();
criteria.and("type").is("MeasurementPoint");
query.addCriteria(criteria);

NearQuery queryN = NearQuery.near(p).maxDistance(new Distance(distance, Metrics.KILOMETERS)).num(range).query(query);
GeoResults<MeasurementPoint> geoPoints = mongoTemplate.geoNear(queryN, MeasurementPoint.class);

Answer 1

不幸的是，不可能对geoNear结果进行排序，因为它不返回游标，默认排序是与点的距离。您可以做的是用Java代码手动对结果进行排序。请注意，代码bellow忽略了距离，只按“时间戳”排序。

List<GeoResult<Person>> results = geoPoints.getContent();
Collections.sort(results, new Comparator<GeoResult<Person>>() {
    @Override
    public int compare(GeoResult<Person> o1, GeoResult<Person> o2) {
        return o1.getContent().getTimeStamp() == 2.getContent().getTimeStamp() ? 0 : 
                (o1.getContent().getTimeStamp() > o2.getContent().getTimeStamp() ? 1 : -1) ;
        }
    });

另一种方法是使用$geowitin和$centersphere。因为你要用一些距离（距离变量）来限制结果，所以这可以起作用。

    Query query = Query.query(Criteria.where("coords").withinSphere(new Circle(p, new Distance(distance, Metrics.KILOMETERS).getNormalizedValue())));
    query.with(new Sort(Direction.DESC, "timeStamp"));
    Criteria criteria = new Criteria();
    criteria.and("type").is("MeasurementPoint");
    query.addCriteria(criteria);

    List<Person> geoPoints = mongoTemplate.find(query, MeasurementPoint.class);

您可以在此处找到有关$GeoWithin和$CenterSphere的更多信息：