J2ME Mobile Application Development - Workshop PPT.

1. J2ME MOBILE APP
DEVELOPMENT
ON-STAGE WORKSHOP
Krishna Engineering College, Coimbatore

2. Agenda
 Programming for Mobile Devices
 Java and Mobile Application Development
 J2ME – Architecture
 How to write Scope for J2ME app
 How to write code for J2ME app
 How to Test J2ME app
 How to Deploy J2ME app
 Utilities and Tools
 Community Best Practices
 Demos
 Discussions

3. Programming for Mobile
Devices
 Advantages
 Mobile is next-gen computing device [smart-phone,
PDA]
 Design, Development, Testing Opportunities [Web /
App]
 Wide Range of Applications required
 Edutainment, Infotainment, business, communication,
social networking … 1000 more…
 Limitations
 Small Size and Low power Handsets
 Operating Systems, Screen Size, Memory, Processor,
Network, Input Methods and Graphics Engine

4. Java and Mobile App
Development
 Opportunities: C++, .NET, Flash-Lite, Java, HTML/JS/PHP, Python
 Java – Independent from Hardware Platform
 Byte Code - Compiler and Code Interpreter
 JVM, KVM [128K of available memory], Card VM
 KVM – C based. Responsible for Byte code to Native calls
 Java for Mobile Operating Systems – J2ME
 Business applications, Games, Mobile Utilities, Location based
Services, Social Media, Communication Tools etc…
 Operating Systems
 Symbian [Feature Phone / Smart Phone]
 Blackberry
 Android
 Windows Mobile
 I-Phone
 Common Java Phones

5. J2ME Market Trends
 900 million mobile Java devices shipped by
2010
 1235 Mobile Java Device Models in Market
 95 Mobile Device vendors using Java
 90000 Mobile Java Applications in Market
 260 Operators worldwide developed java
services
 23 million mobile java downloads every month
 Source– Nokia News, Mobile Today, Symbian
News, Oracle Java Networks

6. J2ME Packages
 Javax.microedition
 Multimedia Supplements
 Content Handlers
 Web Services
 Location based API
 3D Graphics
 Mobile Sensors
 Payment API
 Security
 Wireless Messaging
 XML

7. Limited K-Virtual Machine
Support
 No Floating point Support
 No JNI
 No Thread Groups and Daemon Threads
 Sand box Security

8. J2ME Keywords
 CDC – Connected Device Configuration
[handheld PCs, Smart Devices, Televisions]
 CLDC – Connected Limited Device Configuration
[Mobile Phones, Smart Phones]
 CLDC 1.0
 CLDC 1.1
 Device Profile – MIDP [Mobile Information Device
Profile]
 MIDP 1.0
 MIDP 2.0
 MIDP 2.1

9. Connected Limited Device
Configuration
 CLDC provides the lowest common denominator
for small and resource-constrained devices
 characterized as follows:
 160 kB to 512 kB of totally memory budget available
for the Java platform.
 a 16-bit or 32-bit processor.
 low power consumption, often operating with battery
power.
 connectivity to some kind of network, often with a
wireless connection and with limited (often 9600 bps
or less) bandwidth.

10. MIDP
 MIDP adds an additional layer on the top of
the CLDC providing APIs for a specific class of
devices:
– 128KB of non-volatile memory for the MIDP
implementation
 – 32KB of volatile memory for the runtime heap
 – 8KB of non-volatile memory for persistent data
 – Input capacity (screen, keyboard, touch)
 – Screen size of at least 96x54 pixels

11. Midlets – J2ME Apps
 MIDlet defines methods that the system calls
in order to start, stop (pause), and destroy the
application
 classes to build user interfaces
 Storing data in simple databases [RMS]
 Network Connectivity
 Timer notifications
 .jad and .jar files

12. J2ME – Architecture

13. J2ME - Architecture
Operating System

14. AMS and Midlets
 • The Application Management Software
(AMS) manages the MIDlets.
 • The AMS is a part of the device's operating
environment and guides the MIDlets through
their various states during the execution
process.

15. Structure of MIDP Code
 J2ME SDK 3.0 – Tool Introduction
 Code Example – First J2ME Midlet

16. How to write Scope for J2ME
 Understand the requirement from the mobile
device point of view
 Understand the limitations of device and
network
 Structure of Scope document
 Scope in User case / Story
 Functional Requirements + Functional Flow
 Target Devices + Platform + User Knowledge
 Constraints and Limitations

17. How to write code for J2ME
 Code Sample – Midlet with UI & Fetch System
Properties
 Code Best Practices
 Clean Code
 Follow the Coding Standards – Documentation
 Exception Handling
 Use descriptive variable names
 Don’t Copy-Paste. Use functions
 Use the default structure in Editor
 Understand the Project Properties

18. How to Test J2ME Midlet
 Rule 1: Plan your devices
 Rule 2: Always do Unit Testing in Emulators
 Rule 3: Use real-time Devices for Test cases
verification
 Rule 4: Certify your Midlet
 Rule 5: Sign Midlet for Security reasons

19. How to Deploy J2ME Midlet
 Jad [app-descriptor] and Jar[java-archive]
Files
 Bluetooth & USB
 Public App-Store [getjar.com]
 Branded App-Stores [Symbian Store]

20. Utilities and Tools
 J2ME PLATFORM SDK 3.0
 Borland JBuilder 7 Enterprise with MobileSet 3
 Sun Microsystems' Sun ONE (Open Network
Environment) Studio 4 Mobile Edition
 Metrowerks CodeWarrior Wireless Studio 7
 S5 Systems' jVise (based on IBM Eclipse
technology
 Emulators [J2ME] – Online and PC Based
 UI Design Tools [Prototype and Form Design]

21. Community Best Practices
 Create new requirements and develop apps
 Follow user story + build level scope + clean
code
 Write algorithm before coding
 Do more in Server, Less in Device
 Try simple UI
 Define Target Devices in release notes
 Share Knowledge & Experiences

22. Networking with J2ME Demo
 Networking – Reading from Remote
 Code Sample

23. Discussions…
muthugv@ovi.com
9894238404
http://office.gvmuthu.com
http://twitter.com/#!/gvmuthu