RIA Teacher Gradebook Managing Millions of Students with Swing and Web Services: How we did it

Transcription

1 RIA Teacher Gradebook Managing Millions of Students with Swing and Web Services: How we did it Deane Richan Pearson

2 What we will cover Information about Pearson What's a Gradebook Architecture Overview of a Swing based RIA How to extend using JavaFXTM

3 Pearson at a Glance Benjamin Cummings Allyn & Bacon Addison-Wesley Longman Merrill Scott Foresman Prentice Hall

4 Pearson School Systems Managing Student Information for K-12 Schools and Districts

5 What's a Gradebook

6 Gradebook Requirements Teacher Tool Track Student Progress Interactive and easy to use interface Web Deployment Data centrally stored Cross Platform Scalable / Perform Well

7 Client Technology Options Interactive / Flexible UI Thick Client / Server App Java Web Start FLASH Easy Central Deployment AJAX DHTML HTML Web App

8 High Level Architecture Rich Client Application launched using Web Start Three-tier Architecture Client and Services deployed using Tomcat Http based client-server Protocol Object / Relational Mapping tool Databases (Sybase, Oracle, SQL Server, MySQL)

9 Architecture Stack

10 But Don't Java Apps Look like Something my Cat Coughed Up?

11 Only if YOU let Them! Karsten Lentzsch JGoodies - Metamorphosis

12 When in doubt, borrow...

13 introducing...

14 Gradebook for Teachers

15 Gradebook Demo

16 Key Benefits Cross Platform Mac and Windows Lightweight client application 2mb. Downloads faster than the average mp3 song (only downloaded after updates) Rich / interactive user interface Scales very well

17 Client Architecture Swing / System L&F / Custom Components Http/s Client Server communication also support inproc invocation Application level event framework Dirty state framework All service requests are asynchronous via Busy Worker Resource Bundles for i18n support Deployed as war file on tomcat

18 Client Architecture

19 BAD Client Patterns Don't have a consistent UI Approach Don't Hire a UI/Graphic Designer Never create custom components Never borrow aesthetics from successful applications Create complicated user paradigms and be inconsistent in their implementations Make download size as HUGE as possible

20 BAD Client Patterns cont... Make your client-server communication complicated and difficult to work with Make lots of remote service calls often. Assume the user is NOT roaming and install lots of local file settings etc. Don't design a client architecture or use busy workers Don't use webstart for deployment, stick to shell scripts or batch files

21 Custom Components

22 Busy Worker code example public class BusyWorker { /** * Place busy work in this method. Do not make any UI updates * in this method any data */ public abstract Object work(); /** * Place all UI update code in this method data return from work method */ public abstract void finished(object data);

23 Busy Worker cont... /** * Executes the code implemented in the work method. * Then will execute the code in finished using the * Event Dispatch thread */ public void invokelater() { new Thread() { public void run() { final Object result = work(); SwingUtilities.invokeLater(new Runnable() { }); } } } }.start(); public void run() { finished(result); }

24 Using a BusyWorker /* * Use a busy worker to call services or other long * running tasks */ new BusyWorker() { public Object work() { //DO long running tasks or service calls here return somedata; } public void finished(object data) { //Do work to update the UI here } }.invokelater();

25 Server Architecture Three tier Architecture Services written in Java Deployed as war file on Tomcat Use Http/s for client/server communication Java Data Transfer Objects Cross Platform Mac / Windows Oracle, SQL Server, Sybase, MySQL

26 Server Tips and Tricks Create a Service Layer (Session Facade) Use a Service Locator Pattern Use DB abstraction (ORM etc) Use Http for client/server communication Support server clusters (avoid sticky client sessions) Provide easy server deployment Compress the DTOs if necessary

27 Server tips cont... Create services that work with multiple objects not single objects Avoid queries in loops Create performance related tests to pound the server Write Unit tests to test all service calls

28 Remote options Must use Http XML Rest? SOAP? How about Java! We use our own http invoke mechanism

29 Http Java Service Calls

30 Deployment

31 Extending the application with JavaFX Deploying JavaFX with your application Use JNLP based JavaFX extension Bundle JavaFX jars with your application Embedding JavaFX components into an existing application Circular Dependancies between Java-JavaFX may be complicated Using Ant to build JavaFX components

32 JavaFX Code Example And Demo

33 Questions and Answers

34 Deane Richan