Get nearest location with elasticsearch

Question

I'm building an application that requires elasticsearch to find the nearest location based on latitude and longitude. At the moment I'm able to do this based on a GeoPoint and a maximum distance in kilometers.

@Override
public List<CityDefinition> findCitiesNearby(GeoPoint geo, double distance, String source) {
    LOGGER.info("<findCitiesNearby>");

    FilterBuilder filterBuilderGeo = FilterBuilders.geoDistanceFilter("geo").point(geo.getLat(), geo.getLon()).distance(distance, DistanceUnit.KILOMETERS);

    SearchQuery q = new NativeSearchQueryBuilder()
            .withFilter(filterBuilderGeo);

    List<CityDefinition> fields = esOps.queryForList(q, CityDefinition.class);

    return fields;
}

This works almost perfect but instead of searching within a given distance I want elastic to return the nearest location no matter the distance. Is this possible? If it is, how do I do this?

score 1 · Answer 1 · answered Nov 09 '15 at 08:21

You could sort by distance, rather than filter.

Something along those lines should work:

public List<CityDefinition> findCitiesNearby(GeoPoint geo, double distance, String source) {
    GeoDistanceSortBuilder geoDistanceSort = SortBuilders.geoDistanceSort("geo").point(geo.lat(), geo.lon())
            .unit(DistanceUnit.KILOMETERS).sortMode("ASC")
            .geoDistance(GeoDistance.PLANE);

    final int limit = 1; // if you want only the single nearest result.
    SearchQuery q = new NativeSearchQueryBuilder()
            .withSort(geoDistanceSort)
            .withPageable(new PageRequest(0, limit))
            .build();

    List<CityDefinition> fields = esOps.queryForList(q, CityDefinition.class);

    return fields;
}

score 0 · Accepted Answer · answered Nov 09 '15 at 08:06

0

Apparently it's possible to just remove the distance part.

@Override
public List<CityDefinition> findCitiesNearby(GeoPoint geo, double distance, String source) {
    LOGGER.info("<findCitiesNearby>");

    //FilterBuilder filterBuilderGeo = FilterBuilders.geoDistanceFilter("geo").point(geo.getLat(), geo.getLon()).distance(distance, DistanceUnit.KILOMETERS);

    FilterBuilder filterBuilderGeo = FilterBuilders.geoDistanceFilter("geo").point(geo.getLat(), geo.getLon());

    SearchQuery q = new NativeSearchQueryBuilder()
            .withFilter(filterBuilderGeo);

    List<?> fields = esOps.queryForList(q, CityDefinition.class);

    return (List<CityDefinition>) fields;
}

answered Nov 09 '15 at 08:06

Glenn Van Schil

1,059
3
15
33

could you share more about information how to use the elastic search with location please? How should the data will mapped in the ES? – Iman Tumorang Jan 30 '17 at 14:47
@ImanTumorang I thinks I'm not the right person to explain everything on how ES works with GEO related problems. What I can do is provide you some related docs: https://www.elastic.co/guide/en/elasticsearch/reference/2.4/geo-point.html https://www.elastic.co/guide/en/elasticsearch/reference/2.4/geo-queries.html This should get you on the right track! – Glenn Van Schil Jan 31 '17 at 09:50

Get nearest location with elasticsearch

2 Answers2