Geospatial Search

To support geospatial queries, MongoDB provides various geospatial indexes as well as geospatial query operators.

Prerequisites

• The example below requires a restaurants collection in the test database. To create and populate the collection, follow the directions in github.

• Include the following import statements:

   import com.mongodb.Block;
   import com.mongodb.client.MongoClients;
   import com.mongodb.client.MongoClient;
   import com.mongodb.client.MongoCollection;
   import com.mongodb.client.MongoDatabase;
   import com.mongodb.client.MongoCursor;
   import com.mongodb.client.model.geojson.*;
   import com.mongodb.client.model.Indexes;
   import com.mongodb.client.model.Filters;
   import org.bson.Document;
  

• Include the following code which the examples in the tutorials will use to print the results of the geospatial search:

   Block<Document> printBlock = new Block<Document>() {
          @Override
          public void apply(final Document document) {
              System.out.println(document.toJson());
          }
      };
  

Connect to a MongoDB Deployment

Connect to a MongoDB deployment and declare and define a MongoDatabase instance.

For example, include the following code to connect to a standalone MongoDB deployment running on localhost on port 27017 and define database to refer to the test database:

MongoClient mongoClient = MongoClients.create();
MongoDatabase database = mongoClient.getDatabase("test");

For additional information on connecting to MongoDB, see Connect to MongoDB.

Create the 2dsphere Index

To create a 2dsphere index, use the Indexes.geo2dsphere helper to create a specification for the 2dsphere index and pass to MongoCollection.createIndex() method.

The following example creates a 2dsphere index on the "contact.location" field for the restaurants collection.

MongoCollection<Document> collection = database.getCollection("restaurants");
collection.createIndex(Indexes.geo2dsphere("contact.location"));

Query for Locations Near a GeoJSON Point

MongoDB provides various geospatial query operators. To facilitate the creation of geospatial queries filters, the Java driver provides the Filters class and the com.mongodb.client.model.geojson package.

The following example returns documents that are at least 1000 meters from and at most 5000 meters from the specified GeoJSON point com.mongodb.client.model.geojson.Point, sorted from nearest to farthest:

Point refPoint = new Point(new Position(-73.9667, 40.78));
collection.find(Filters.near("contact.location", refPoint, 5000.0, 1000.0)).forEach(printBlock);