hi,
i have given presentation on Android ,
you can cover following points :
1) Definition of Android
2) Features
3) Architecture
4) Advantages
5) Android Vs J2ME
i prepared power point presentation as well as some notes : you can
prepare presentation with help of notes ":::::
Definition of android?
Android is an emerging mobile technology
Android is a software stack for mobile devices that includes an
operating system, middleware and key applications. This early look at
the Android SDK provides the tools and APIs necessary to begin
developing applications on the Android platform using the Java
programming language.
For the developer, Android is a new mobile platform based on Java
running on top of a Linux kernel. For now, Java is the only
development language available. Android has a complete set of
application programming interfaces available for everything from user-
interface components to accessing location information
2 ) FEATURES ::::::::::::::::;
* Application framework enabling reuse and replacement of
components
* Dalvik virtual machine optimized for mobile devices
* Integrated browser based on the open source WebKit engine
* Optimized graphics powered by a custom 2D graphics library; 3D
graphics based on the OpenGL ES 1.0 specification (hardware
acceleration optional)
* SQLite for structured data storage
* Media support for common audio, video, and still image formats
(MPEG4, H.264, MP3, AAC, AMR, JPG, PNG, GIF)
* GSM Telephony (hardware dependent)
* Bluetooth, EDGE, 3G, and WiFi (hardware dependent)
* Camera, GPS, compass, and accelerometer (hardware dependent)
* Rich development environment including a device emulator, tools
for debugging, memory and performance profiling, and a plugin for the
Eclipse IDE
3) What Benefits Does Android Have?
For the mobile developer, Android has a number of benefits over other
platforms.
Android is an open platform, both in the open source sense and in the
open API sense. Several stock applications, such as the contact
application and the web browser, will be distributed on Android
handsets and are being developed with application interaction in mind.
Google is also providing some core services that are not readily
available on other platforms. Developers will have access to Google
Maps to display location information. A messaging service for peer-to-
peer communication without the use of SMS, as is common on competing
platforms, will also be available. This is another case of enabling
application innovation that either isn't available on other phones or
would be cost-prohibitive to replicate.
The goal is to allow for new and innovative applications that either
can't be done on existing platforms or simply haven't been allowed.
(This openness extends beyond simply providing access to the data on
the handset. Included applications can be customized or even replaced
entirely. For example, a corporation could replace the messaging
application with one that only allowed secure messaging through the
company's servers or a user could replace the included photo viewer
with one of their choosing.)
The Android APIs are extensive and modern. In addition to the typical
APIs for screen drawing, user input, and network access, you'll find
APIs for storage, media, graphics, and even direct hardware access.
Media APIs are available for both playback and recording of audio,
video, and still images. For storage, developers aren't limited to
file-based APIs. SQLite is available for relational data storage, a
preferences API is available for simple setting storage, and
applications can extend the data storage mechanisms available. OpenGL
ES, with optional hardware acceleration, is available for 3D graphics
applications. Lastly, there will be a set of low-level APIs for direct
access to the hardware, such as WiFi or Bluetooth. Most mobile
platforms don't allow low-level access to the hardware, but Android
allows developers to extend the hardware on a given handset. (For
instance, it might be possible to add support for Bluetooth profiles
that weren't provided out-of-the-box.)
Security is essential with such an open development environment.
Therefore, a tight security model is built into Android. Applications
are only granted required permissions (data access, APIs used, and so
forth) at installation time and cannot change their permissions later.
So, an application can't remotely add a new feature to, say, read a
user's location with or without the user's permission. This is a big
step towards preventing malware and easing privacy and safety concerns
for users of the platform.
4) Fast & easy application development
With Android, a developer could build an application that enables
users to view the location of their friends and be alerted when they
are in the vicinity giving them a chance to connect.”
“Android provides access to a wide range of useful libraries and tools
that can be used to build rich applications. For example, Android
enables developers to obtain the location of the device, and allows
devices to communicate with one another enabling rich peer-to-peer
social applications.( In addition, Android includes a full set of
tools that have been built from the ground up alongside the platform
providing developers with high productivity and deep insight into
their applications.”)
Other nice features that are easy to use with Android are Animations
and media-playback.
playback of: ogg-Vorbis, MIDI and a bunch of other formats.
5 ) Dalvik.equals(Java) == false
Why “Dalvik”? –Dalvik is the name of Android's virtual machine. It is
an interpreter-only virtual machine that executes files in the Dalvik
Executable (*.dex) format, a format that is optimized for efficient
storage and memory-mappable execution. The virtual machine is register-
based, and it can run classes compiled by a Java language compiler
that have been transformed into its native format using the included
"dx" tool. (The VM runs on top of a Linux 2.6 kernel, which it relies
on for underlying functionality (such as threading and low level
memory management). The DalvikVM was also optimized to be running in
multiple instances with a very low memory-footprint. Several VMs
protect ones application from being dragged down by another crashed
Application.)
Differences to a normal JavaVM
JavaVM’s one can find on almost any desktop computer nowadays are
Stack-based Virtual Machines (VM).The DalvikVM on the other hand is
register based, because on mobile-processors are optimized for
register-based execution. Also of register-based VMs allow faster
execution times at the expense of programs which are larger after
compilation.
Even though langages used for developement is java, its very much
differnt . Most of the classes for J2ME are not available on android,
or atleast its with some other name.
6) Android vs. Java ME vs. BREW:::::::::
A BREW application will, in the vast majority of all cases, consist of
a
single applet. That applet communicates with the rest of the handset
through receiving and sending events. You can think of a Java ME
application, on the other hand, as an extension of the Midlet class.
The
midlet has functions for starting, stopping, pausing, key handling,
and
performing any other interaction between the handset and application.
A Android applications can have any number of activities registered
with the
handset through the AndroidManifest.xml file. Android’s multiactivity
architecture is probably the major difference between developing for
Android and developing for other handset SDKs. This single fact makes
it
much easier to write modular, compartmentalized code. In BREW and Java
ME, a developer will implement most functionality within the confines
of
the midlet or the applet. In Android, you can write an activity,
content
handler, intent receiver, or service to handle nearly anything. Once
you’ve
written an activity to edit a text file, you can refer to this
activity in all
future applications you write by sending and receiving intent actions.
This
isn’t to say that such architecture isn’t possible within BREW or Java
ME.
It just has to be done at the Java, C, or C++ level or, in Brew, with
cumbersome extensions instead of being built smoothly into the
application
framework.
Java ME application usually consists of a single midlet.
On Oct 1, 7:11 pm, "nicolas.deloof" <[EMAIL PROTECTED]> wrote:
> Hello,
>
> my JUG members request for an "Androïd" meeting. As I can't find
> anybody localy to speack on this subject, I planed to perpare a "code
> lab", with a small introduction on android (based on SDK and web
> available slides), and a live-coding of some simple androïd
> application.
>
> Did anyone allready do such a meeting ? Do you have any suggestion of
> a good tutorial we could follow ? Could Google France give us some
> help to organize the event ?
>
> Nicolas, for the BreizhJug (Java User Group Rennes, France)
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