Dot allowed in key names

import com.mongodb.Mongo;

import com.mongodb.DBCollection;

import com.mongodb.BasicDBObject;

import com.mongodb.DB;

public class Test {

    public static void main(String[] args) throws Exception {

        Mongo m = new Mongo();

        DB db = m.getDB("test_db_1");

        DBCollection coll = db.getCollection("test_collection_1");

        BasicDBObject doc = new BasicDBObject();

        doc.put("name.first", "First Name");

        doc.put("name.last", "Last Name");

        coll.insert(doc);

    }

}