This document discusses project management concepts for a project using Google App Engine, including tasks, dependencies, risks, and responsibilities. It also provides examples of storing and querying data on Google App Engine using the Datastore API and JSP pages. Code snippets are given for creating entities, properties, queries, and retrieving results to display images and videos associated with a user.

1. Project Management
José Luis Santos
joseluis.santos@cs.kuleuven.be

2. What do you have?
1. Milestones A QUANTIFIED LEARNING TEAM
2. Project
3. Technology
4. Class diagram
5. Use case
6. Scenarios
7. and…

3. What is the next step?

4. How can we do it?
Tasks Dependencies
Risks Responsibilities

5. How do we define a task?
To learn JQUERY
To implement the model
To implement the control part
(Servlets)
To design the interface

6. Take care!!!!
Design tasks are low time consuming…
… while implementation tasks are
high time consuming

7. Take care!!!!
Design tasksare easily addressable…
… while implementation tasks are
sometimes complex to fix them

8. What is a dependency?
Task A Task B
Design Implementation
Interface Controller

9. What is a risk?
Take them seriously!!!!

10. Who knows why it failed?

11. What can we do?

12. Data Store
(Google App Engine)
José Luis Santos
joseluis.santos@cs.kuleuven.be

13. Servlet
DatastoreServicedatastore = DatastoreServiceFactory.getDatastoreService();
Entity person = new Entity("Person", "test");
person.setUnindexedProperty("name", "TestUser"); //Unindexed properties for these properties that you will
not filter on
Entity weddingPhoto = new Entity("Photo", person.getKey()); // We link this Entity to another (Foreign key)
weddingPhoto.setProperty("imageUrl", "http://scm-l3.technorati.com/11/02/05/25749/marriage.jpg");
weddingPhoto.setProperty("date", new Date());
Entity weddingVideo = new Entity("Video", person.getKey()); // We link this Entity to another (Foreign key)
weddingVideo.setProperty("videoUrl", "http://www.criticallayouts.com/images/rsgallery/original/just-
married-cans-ag1.gif");
weddingVideo. setUnindexedProperty("date", new Date());
datastore.put(person);
datastore.put(weddingPhoto);
datastore.put(weddingVideo);
req.setAttribute("Key", person.getKey()); //Sending an object to a jsp file
RequestDispatcher dispatcher = getServletContext().getRequestDispatcher("/store.jsp");
dispatcher.forward(req,resp);

14. JSP
DatastoreServicedatastore = DatastoreServiceFactory.getDatastoreService();
Key key = (Key)request.getAttribute("Key"); //We get an object not only an String
if (key != null){
Query userMediaQuery = new Query();
userMediaQuery.setAncestor(key);
// Ancestor queries return ancestors by default. This filter excludes the ancestor from query results.
userMediaQuery.addFilter(Entity.KEY_RESERVED_PROPERTY, Query.FilterOperator.GREATER_THAN, key);
// Returns both weddingPhoto and weddingVideo even though they are different entity kinds.
List<Entity> results = datastore.prepare(userMediaQuery).asList( FetchOptions.Builder.withDefaults());
for (inti=0;i<results.size();i++){
if (results.get(i).getKind().compareTo("Video")==0){%>
This is a photo:<br/><imgsrc="<%=results.get(i).getProperty("videoUrl")%>"></img><br/>
<% }else if (results.get(i).getKind().compareTo("Photo")==0){%>
This is a video:<br/><imgsrc="<%=results.get(i).getProperty("imageUrl")%>"></img><br/>
<% }%>

15. Objectify
http://code.google.com/p/objectify-
appengine/wiki/IntroductionToObjectify