Objective vs Java or Python API

We are currently using Google Data Store and Objectify to return query results back to the front end. I am currently doing performance comparisons between Data Store and Cloud Storage for returning lists of key values. My question is whether using Ob

Request and error GAE and Objectify using order ()

I am just working on a Demo project and one of the methods provides a basic query on a Type. public List<Conference> filterPlayground(){ Query<Conference> query = (ofy().load().type(Conference.class)).order("name"); query = query.fil

Store instances in a field

First off, I'm sure this question is trivial for anyone that has ANY amount of experience with Objectify- however, unfortunately I don't. Say I have a POJO named University. One of its fields is a list of Professors (where Professors is also POJO). W

how to apply a date filter to an ancestor query

I have two entity model Student and attendance such that each attendance entity has associated student parent. Attendance model: @Entity public class Attendance { @Id Long id; @Index Date date; @Parent @Index @ApiResourceProperty(ignored = Annotation

Storing users in the datastore with unique email addresses

So I'm working on a project in Java, but really the language doesn't matter here. So I want to create and store users in the datastore and I'm trying to work out the best way to do this, such that I can ensure an email is not used more than once. So

Objectify Translator as a JPA attribute converter

I have a POJO structure like this @Entity public class ClassA { @Id public Long id; public ClassB classbObject; } And another class @Entity public class ClassB { @Id public Long id; public String fieldA; public String fieldB; } Now, basing on custom

Objectify Space Search, appengine

I want to use, objectify for spatial search. I have entities that have longitude and latitude associated with them. Latitude and longitude information is dynamic e.g. service providers (like electrician, carpenter) in a city. I want to implement a qu

Objectify: Filter by an attribute of collection entries?

I'm using Objectify on Google's AppEngine. I have the following Entity-Model: @Entity public class ChallengeEntity { @Id private Long id; @Index public List<ChallengeParticipant> participants; } The Participant (not an entity... should it be one?) p

Objectify - cleaning sessions

My original HttpSessionListener code: public class SessionListener implements HttpSessionListener { @Override public void sessionDestroyed(HttpSessionEvent event) { final Object user = event.getSession().getAttribute("user"); if (user != null &a

AppEngine Objectify: How does it handle object merging?

I read that objectify can handle multiple requests from different clients. During a transaction it throws an Exception if the second client tries to update the same object. They recommend to send the request again, if such an exception was thrown. cl

Query selected fields in an entity in objectio - appengine

I am using appengine and objectify as a backend for my app. And when i query in the datastore i get a Entity object which has the data of required row. But, using objectify how will i query entities and get oly selected fileds from it? because queryi

No class errors recorded after the new instance

I'm running an app with a Google App Engine server as a backend, using Objectify for datastore interactions. The nature of the app means that there are occasional very sharp spikes in demand. When the spikes happen, GAE spins up new instances. The pr

Objectify, Key & lt; & gt; it's possible? Workarounds?

What I mean by type is something that would allow me to do the following. public class AnyObject{ List<this.type> list; } I know the following dosen't work. public class AnyObject{ List<this.getClass()> list; } So how would I create a lets say

Parallel updates to the different properties of the entity

I'm using JDO to access Datastore entities. I'm currently running into issues because different processes access the same entities in parallel and I'm unsure how to go around solving this. I have entities containing values and calculated values: (key

Maximum length of string stored with App Engine?

When storing String fields with App Engine: What is the maximum length() of the String that App Engine datastore can handle? Also if using Objectify, is this max length the same or Objectify does some processing that affect this max length?Objectify

Objectify Entity

Can I pass an objectify entity (i.e class annotated by @Entity) to a function accepting com.google.appengine.api.datastore.Entity ?No. Java is a typed language. You can only pass subclasses of com.google.appengine.api.datastore.Entity to a function w

How to get the entity with the most recent date

Does anyone have any idea how to retrieve the last(with the newest date) entity in objectify? I know how to make a query but how to retrieve the one with the newest date? List<Transaction> fetched2 = ofy.query(Transaction.class).filter("somepro

@Embedded & amp; @Id questions

I am new to Objectify and I had some doubts that is best illustrated in code public class Uid { @Id private String name; // e-mail id private String oauth2_token; // A token ... // constructors/setters/getters }; public class Message { @Id Long msg_i

The sort order is ignored in the Objectify request

I have a GAE Entity called MyFile public class MyFile { static enum LocationEnum {Folders, Hidden}; static enum FileType {File, Folder); @Id private Long id; private Key<MyFile> parent; private String name; private LocationEnum location; private Fil

Achieve good paging using objectified

I'm using objectify cursors to achieve basic paging, basically creating a more button.. How best do you achieve paging using objectify for building links that allow users to go forward and backwards. Something more like a page list.. 1, 2, 3, 4, more

When do you register courses in Objectify for GAE?

So this might be kind of a dumb question but when do you register classes with: ObjectifyService.register( User.class ); Currently, I'm doing this in the constructor of an interface-like class that I use in my other classes to simplify usage of the D

Get a random entry from the Objectify entity

How can I get a random element out of a Google App Engine datastore using Objectify? Should I fetch all of an entity's keys and choose randomly from them or is there a better way?Assign a random number between 0 and 1 to each entity when you store it