j2me prepared by: - gaery- ronny - alan- andy. why technology for mobile devices? the nature of...
Post on 20-Dec-2015
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Why Technology for Mobile Devices?Why Technology for Mobile Devices?
The nature of wireless devices is changing Old devices:
All the software hard-coded by the device manufacturer
New devices: Can be customized by dynamically loading
software over the air New opportunities for manufacturers,
operators, and developers!
What is What is J2ME ?J2ME ?
• A collection of Java APIs for the development of software for resource constrained devices such as PDAs and cell phones.
• Provides a robust, flexible environment for applications running on those devices.
J2ME complements configurations with profiles, software to match the hardware. Each configuration supports several profiles. The most common profile in mobile phones is MIDP, the Mobile
Information Device Protocol, which adds networking, user interface, and persistent storage support to the CLDC configuration.
Requirement for MIDP: screen at least 96 pixels wide and 54 pixels tall
J2SE re-use J2ME is designed to re-use J2SE code wherever possible, or at least
to pretend to. Within the scope of features supported by a given configuration and
set of profiles, wherever possible the J2ME implementation must not change interfaces or behavior from the J2SE original.
Why is J2ME useful…Why is J2ME useful…
Allow mobile devices to run full application.
Creates a graphical user interface for applications in the mobile devices.
What kinds of problems What kinds of problems does this technology solve does this technology solve well well ?
MIDlet – J2ME SoftwareMIDlet – J2ME Software
MIDP applications are called MIDlets. MIDlets are groups of classes, one of which is
derrived from the abstract class javax.microedition.midlet.MIDlet
The user selects and launches the MIDlet. At this point, the MIDlet enters the KVM and the
lifecycle methods of the MIDlet are invoked.
Why is it cool?Why is it cool?
J2ME developers can develop on their PC and test the code using an emulator
Most applications written in Java can be virtually shown in the mobile devices.
Sample Codes and Applications . . .
Why is it cool?Why is it cool?
WAP (Wireless Application Protocol) was designed to allow wireless devices, and their limited screens and connection speeds, to access Internet and intranet applications.
The goal was to offer a license-free standard to the entire wireless industry so that anyone would be able to develop WAP-based services.
WAP standardizes access not only for mobile phones but also for PDAs (personal digital assistants) and pagers.
What is WAP?
Pros optimized for mobile networks with narrow bandwidths.
Good for mobile devices with small screens and Limited keys for user entry.
Good for devices with little memory storage and limited processing and battery power.
Faster loading time.
Cons
User interface is very minimal.
•Low security.
Requires constant airtime for stand-alone or offline operations.
Ajax for mobile web environmentAjax for mobile web environment
Shorthand for Asynchronous JavaScipt and XML
The Ajax technique uses a combination of:
XHTML, HTML, and CCS stylesheet. Document Object model , JavaScript. XMLHttpRequest XML
What is .Net Mobile
.NET Mobile is a set of server-side Web Forms and Controls for building applications for wireless mobile devices, like web phones and PDAs.
.NET Mobile is an extension to Microsoft ASP.NET and the Microsoft's .NET Framework.
Why .Net Mobile?
Different mobile devices support different programming languages. Some support WAP and WML, some support HTML or a limited version of HTML, and some support both or a different language.
To support all types of mobile devices, developers must create one different application for each language.
Why .Net Mobile?
Support for Multiple Markup Languages Cell phones and other devices that use
Wireless Application Protocol (WAP) to display Wireless Markup Language (WML)
Devices such as Pocket PCs, which display Hypertext Markup Language (HTML) content
Write Once, Access from Multiple Devices
How does it work?
A web client requests a web page
The request travels the Internet
The request is received by IIS
The request is handled by the .NET framework
.NET Mobile handles any mobile device requirements
The page is returned to the client
What set J2ME apart from the other?
J2ME is the most popular web technology that is used by today’s mobile devices.
Allows mobile devices to run applications written in JAVA.
Little difference if compared with .NET mobile because .NET is also an Integrated Development Environment.