Question

Querying geospatial data in mongodb looks straight forward enough through the shell script, however, I’m trying to replicate some code in morphia (playmorphia).

Get all points within a certain radius, docs say:

> center = [50, 50]
> radius = 10
> db.places.find({"loc" : {"$within" : {"$center" : [center, radius]}}})

Here’s my code in my Peak model:

Double[] loc = new Double(2);
// it's set to my [Longitude, Latitude]

List<Peak> peaks = play.modules.morphia.Model.ds().find(Peak.class).field("loc").near(loc[0], loc[1], 10/111.12).limit(50).asList();

It works but am I doing something wrong by using the ds().find()? Is there a more elegant way to do this using the model e.g. Peak.find..? Thanks!

Answer 1

You need to put indexes on geo fields.

Sample code from my project:

@Indexed(IndexDirection.GEO2D)
public Double[] geo = new Double[2];


List<User> pharmacist = MorphiaQuery.ds()
.createQuery(User.class)
.filter("isPharmacist",true)
.field("geo")
.within(nelat, nelng, swlat, swlng)
.field("geo")
.near(u.geo[0], u.geo[1])
.limit(limit)
.asList();

Check the manual:
http://code.google.com/p/morphia/wiki/Query#Geo-spatial