fail.java

        MongoClient cl = new MongoClient();
        MongoDatabase db = cl.getDatabase(mDb);
        MongoCollection coll = db.getCollection(mColl);


        double avg = 0.0;
        long docs = 0;
        long vals = 0;

        System.out.println("Starting to query the data...");
        Bson fields = fields(include(mField), excludeId());

        long start = System.nanoTime();
        MongoCursor<Document> cursor = coll.find().projection(fields).iterator();

        while (cursor.hasNext()) {
            docs++;
            final Object field = cursor.next().get(mField);

            if (field.getClass() == ArrayList.class) {
                final List<Double> list = (List<Double>)field;
                for (Double d : list) {
                    vals++;
                    avg += d/271403.0;
                }
            } else {
                vals++;
                avg += ((Double) field)/271403.0;
            }
        }

        long done = System.nanoTime();
        long elapsed = done - start;
        System.out.println("avg is " + String.valueOf(avg) + " got in " + String.valueOf(elapsed/1000/1000) + "ms");
        System.out.println(String.valueOf(docs) + " docs have been parsed and " + String.valueOf(vals) + " values have been processed");