Computer Science Wi-Fi App using J2ME and MVC Architecture

Advisor : Dr. Chung-E WangDepartment of Computer ScienceSacramento State UniversityDate: 04/25/05

Praveen Chirumamilla

Agenda

Motivation Purpose J2ME MVC Pattern Project design overview Improvements Summary

Motivation

Semester begins – check course schedule - Labs has long waiting lines

out of town – grade check – no computer

Why not use cell phone to do these..?

Purpose

Provide Students facility to schedule appointment, check their grades and class schedule using their cell phones

Explore J2ME, NetBeans Mobile IDE Understand & implement MVC

architecture

NetBeans Full-featured Java Open Source IDE Syntax highlighting code editor Offers unmatched support for J2ME MIDP

2.0 and CLDC 1.1 mobile environment J2EE development Performance Profiler Visual design tool Sun Public License

Where does J2ME fit in Java 2 Platform?

Java™ 2 PlatformServers

Servers

Java 2Enterprise

Edition(J2EE)

Java 2StandardEdition(J2SE)

OptionalPackages

OptionalPackages

Java 2 Micro Edition (J2ME)

Java Virtual Machine KVM

CLDCCDC

MIDPFoundation Profile

Personal Profile

Java Card APIs

CardVM

Desktopmachines

Desktopmachines

High-endconsumerdevices

High-endconsumerdevices

Low-endconsumerdevices

Low-endconsumerdevices

Smart-cards

Smart-cards

J2ME Configurations and Profiles

Java HotSpot ™ Java Virtual Machine (JVM) Card VM

Java Programming Language

Java 2Enterprise

Edition(J2EE)

Core APIs

Java 2StandardEdition(J2SE)

Core APIs

Java 2 Micro Edition Core APIs

PersonalProfile

RMIProfile

Other CDC

Profiles...

FoundationProfile

Mobile InformationDevice Profile

OptionalPackages

Java™ 2 Platform, Micro Edition (J2ME™) encompasses VMs and core APIs specified via Configurations as well as vertical—or market-specific—APIs specified in Profiles

OptionalPackages

KVM

Java Card APIs

Profile? A collection of Java technology-based

APIs that supplement a Configuration to provide capabilities for a specific “vertical” market or device type

Adds features that are specific to a certain device category such as cell phones or PDAs

One profile defined Mobile Information Device Profile

Mobile Information Device Profile

Targets mobile two-way communication devices implementing J2ME CLDC

Profile addresses Display toolkit, User input methods Persistent data storage using simple

record-oriented database model HTTP-based networking using CLDC

Generic Connection framework

CLDC and MIDP Architecture

MIDP ProfileApplications

OEMApplications

MID Profile

CLDC (KVM)

Operating System

OEMAPIs

MIDP Application Lifecycle MIDP applications are known

as “MIDlets” MIDlets move from state to

state in the lifecycle, as indicated. Start – acquire resources and start

executing Pause – release resources and

become quiescent (wait) Destroy – release all resources,

destroy threads, and end all activity

Pause

Active

Destroyed

star

tAp

pd

estr

oyA

pp

pau

seA

pp

des

tro

yAp

p

MVC: Model-View-Controller Model-View-Controller

Architectural pattern for building systems Divide system responsibilities into three parts

Model Contains all program data and logic

View Visual representation of model

Controller Defines system behavior by sending user input to model

Step by step User uses controller to change data in model Model then informs view of change View changes visual presentation to reflect change

Model-View-Controller Architecture

Model Application data

View Graphical presentation components

Controller Logic for processing user input

notifiesmodifiesModelC ontroller View

Elements of MVC design pattern

User

View Controller

Model

notifies of the update

registers changes and actions

user actions

UI presentation

Project overview

View MVCMIDlet

Model

Runnable

Improvements

Synchronize the data between SMCD and admissions department

Send as SMS to students of the class when grades are posted

Summary

J2ME, MIDP, MVC Concepts Project design