This document provides an introduction to mobile application development. It describes the characteristics of mobile devices and outlines the Java 2 Micro Edition (J2ME) architecture, including the Connected Limited Device Configuration (CLDC) and Mobile Information Device Profile (MIDP). CLDC defines core Java APIs for limited devices, while MIDP provides user interface and networking APIs for mobile phones. A MIDP application called a MIDlet follows a lifecycle of being created, started, paused, and destroyed by the device's Application Management System (AMS).

1. 01 Introduction to Mobile
Application Development
Mobile Application Development 1

2. Objectives
At the end of the lesson, the student should be able to:
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Identify the characteristics of mobile devices
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Describe the J2ME architecture
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Know the role of configurations and profiles
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Identify the APIs provided by MIDP
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Describe the MIDlet life cycle
Mobile Application Development 2

3. Mobile Application Devt
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Mobile Devices
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Java 2 Micro Edition
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CLDC
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CDC
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MIDP
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MIDlets Mobile Application Development 3

4. Mobile Devices
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Small in size
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Limited memory
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Limited processing power
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Low power consumption
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Robust and reliable
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Limited connectivity
Mobile Application Development 4
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Short wakeup time

5. Mobile Application Devt
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Mobile Devices
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Java 2 Micro Edition
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CLDC
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CDC
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MIDP
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MIDlets Mobile Application Development 5

6. Java Platform
Servers
Servers
Desktop
machines
High-end
Optional consumer
Packages
devices Low-end
consumer
Optional
Packages devices
Smart
Cards
J2EE Personal Profile
J2SE
Foundation Profile MIDP
Java
CDC CLDC
Card
Java Virtual Machine KVM Card VM
Java 2 Micro Edition (J2ME)
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7. J2ME Architecture
Applications
Optional OEM
Profile
Packages APIs
Libraries
Configuration {
Java Virtual Machine
Device Operating System
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8. Configuration
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the subset of the Java programming language
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the functionality of the Java Virtual Machine (VM)
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core platform libraries
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security and networking features
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9. Profiles
A profile defines additional sets of APIs and features
for a particular market, device category or industry.
While a configuration defines the base libraries,
profiles define the libraries that are important to
make effective applications. These libraries include
the user interface, networking, and storage APIs.
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10. Mobile Application Devt
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Mobile Devices
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Java 2 Micro Edition
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CLDC
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CDC
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MIDP
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MIDlets Mobile Application Development 10

11. CLDC
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Java language and Virtual Machine (VM) features
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Core libraries (java.lang.*, java.util.*)
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Input/Output (java.io.*)
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Security
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Networking
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Internationalization Application Development
Mobile 11

12. Missing Features
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finalization of class instances
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asynchronous exceptions
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some error classes
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user-defined class loaders
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reflection
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Java Native Interface (JNI)
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thread groups and daemon threads
Mobile Application Development 12

13. CLDC Device Characteristics
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at least 192kb of memory for Java platform (160kb non-
volatile memory for VM and libraries and 32kb volatile
memory for VM runtime)
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16 or 32 bit processor
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low power consumption (usually battery powered)
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limited, intermittent network connection with limited
bandwidth (usually wireless)
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14. Class Verification
File.java
Install
compile (javac) verify
(runtime)
File.class
preverify interpret
File.class
Development Machine Target Device
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15. Generic Connection Framework
Connection
Str eamConnectionNotifier Dat agr amConnection
InputConnection OutputConnect ion
Str eam Connection
Content Connect ion
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16. Mobile Application Devt
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Mobile Devices
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Java 2 Micro Edition
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CLDC
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CDC
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MIDP
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MIDlets Mobile Application Development 16

17. CDC
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java.io ●
java.security
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java.lang ●
java.security.cert
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java.lang.ref ●
java.text
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java.lang.math ●
java.util
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java.net ●
java.util.jar
●
java.util.zip
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18. JWTI
MIDlets
WMA MMAPI Optional OEM
MIDP 2.0
1.1 1.1 Packages APIs
CLDC 1.0 or 1.1
Device Operating System
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19. Mobile Application Devt
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Mobile Devices
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Java 2 Micro Edition
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CLDC
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CDC
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MIDP
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MIDlets Mobile Application Development 19

20. MID Device
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Display:
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Screen-size: 96x54
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Display depth: 1-bit
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Pixel aspect ratio: approximately 1:1
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Input:
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One or more of the following user-input mechanisms: one-
handed keyboard, two-handed keyboard, or touch screen
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21. MID Device
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Memory:
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256 kilobytes of non-volatile memory for the MIDP
implementation, beyond what's required for CLDC.
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8 kilobytes of non-volatile memory for application-created
persistent data
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128 kilobytes of volatile memory for the Java runtime (e.g.,
the Java heap)
Mobile Application Development 21

22. MID Device
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Networking:
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Two-way, wireless, possibly intermittent, with limited
bandwidth
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Sound:
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The ability to play tones, either via dedicated hardware or
via software algorithm.
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23. Mobile Application Devt
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Mobile Devices
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Java 2 Micro Edition
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CLDC
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CDC
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MIDP
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MIDlets Mobile Application Development 23

24. MIDlet
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A MIDP application is called a MIDlet. The device's
application management software (AMS) interacts directly
with the MIDlet with the MIDlet's create, start, pause, and
destroy methods.
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The MIDlet is part of the javax.microedition.midlet package.
A MIDlet must extend the MIDlet class. It can request
parameters from the AMS as defined in the application
descriptor (JAD).
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A MIDlet does not have (and MUST NOT have) a public
static void main(String[] argv) method. It will not be
recognized by the AMS as the program's starting point.
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25. MIDlet Life Cycle
new
destroyApp()
startApp() Paused
Destroyed
Active pauseApp()
destroyApp()
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26. Summary
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Mobile Devices
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Java 2 Micro Edition
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CLDC
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CDC
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MIDP
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MIDlets Mobile Application Development 26