import org.bson.Document;

import com.mongodb.client.MongoClients;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.model.FindOneAndUpdateOptions;
import com.mongodb.client.model.ReturnDocument;

public class MongoFindOneAndUpdateTest {

	public static void main(String[] args) {
		// I'm running mongo 3.4 locally
		final String connStr = "mongodb://localhost:27017/test?ssl=false";
		final MongoCollection<Document> col = MongoClients.create(connStr)
				.getDatabase("test").getCollection("fakeCol");
		// Make sure we start with an empty collection
		col.drop();
		// insert a simple document
		col.insertOne(new Document()
				.append("_id", "fakeId")
				.append("one", 1)
				.append("foo", "bar"));
		{
			final Document doc = col.find().iterator().next();
			System.out.println(doc.toJson());
			// prints { "_id" : "fakeId", "one" : 1, "foo" : "bar" } as expected
		}
		{
			// Find a document with no filter and update it with no operation,
			// and then return the updated document, at least that's what I expected to happen.
			final Document doc = col.findOneAndUpdate(new Document(), new Document(),
					new FindOneAndUpdateOptions().returnDocument(ReturnDocument.AFTER));
			System.out.println(doc.toJson());
			// prints { "_id" : "fakeId" }
			// What???
		}
		{
			// Just to be sure the previous result is correct
			final Document doc = col.find().iterator().next();
			System.out.println(doc.toJson());
			// prints { "_id" : "fakeId" }
			// Yeah, the document was for some reason obliterated
		}
		col.drop();
	}

}