// 2. Tunable consistency controls
String connectionString = "mongodb://localhost/?readPreference=secondaryPreferred";
 
MongoClient client = new MongoClient(new MongoClientURI(connectionString);
 
MongoDatabase database = client.getDatabase("myDatabase");
MongoCollection<Document> collection = database.getCollection("myCollection");
 
// Start client session, which is causally consistent by default
try (ClientSession session = client.startSession(ClientSessionOptions.builder().build())) {
  //Run causally related operations within the session
  collection.insertOne(session, ...);
  collection.updateOne(session, ...);
 
  try (MongoCursor<Document> cursor = collection.find(session).filter(...).iterator()) {
    while (cursor.hasNext()) {
      Document cur = cursor.next();
    }
  }
}