항상 기본에 충실해야한다는 생각이 든다.
오늘 부터 한 칼럼씩 Android Dev Guide를 학습하여 정리하려고한다.
영어 정말 못한다. 그래도 GoGo 씽
Android is a software stack for
mobile devices that includes an
operating
system, middleware and key applications. The
Android SDK provides the
tools and APIs necessary to begin developing applications on the Android
platform using the
Java programming language.자바기반 모바일 OS . 란다..MS - Window Mobile
애플 - Iphone SDK
팜프리
노키아 - 심비안
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
Android Architecture
The following diagram shows the major components of the Android operating
system. Each section is described in more detail below.
Applications
Android will ship with a set of core applications including an email client,
SMS program, calendar, maps, browser, contacts, and others. All applications are
written using the Java programming language.
Application Framework
Developers have full access to the same framework APIs used by the core
applications. The application architecture is designed to simplify the reuse of
components; any application can publish its capabilities and any other
application may then make use of those capabilities (subject to security
constraints enforced by the framework). This same mechanism allows components to
be replaced by the user.
Underlying all applications is a set of services and systems, including:
- A rich and extensible set of Views that can be used to build an
application, including lists, grids, text boxes, buttons, and even an embeddable
web browser
- Content
Providers that enable applications to access data from other applications
(such as Contacts), or to share their own data
- A Resource
Manager, providing access to non-code resources such as localized strings,
graphics, and layout files
- A Notification
Manager that enables all applications to display custom alerts in the status
bar
- An Activity Manager that
manages the lifecycle of applications and provides a common navigation backstack
For more details and a walkthrough of an application, see the Notepad Tutorial.
Libraries
Android includes a set of C/C++ libraries used by various components of the
Android system. These capabilities are exposed to developers through the Android
application framework. Some of the core libraries are listed below:
- System C library - a BSD-derived implementation of the
standard C system library (libc), tuned for embedded Linux-based devices
- Media Libraries - based on PacketVideo's OpenCORE; the
libraries support playback and recording of many popular audio and video
formats, as well as static image files, including MPEG4, H.264, MP3, AAC, AMR,
JPG, and PNG
- Surface Manager - manages access to the display subsystem
and seamlessly composites 2D and 3D graphic layers from multiple applications
- LibWebCore - a modern web browser engine which powers both
the Android browser and an embeddable web view
- SGL - the underlying 2D graphics engine
- 3D libraries - an implementation based on OpenGL ES 1.0
APIs; the libraries use either hardware 3D acceleration (where available) or the
included, highly optimized 3D software rasterizer
- FreeType - bitmap and vector font rendering
- SQLite - a powerful and lightweight relational database
engine available to all applications
Android Runtime
Android includes a set of core libraries that provides most of the
functionality available in the core libraries of the Java programming
language.
Every Android application runs in its own process, with its own instance of
the Dalvik virtual machine. Dalvik has been written so that a device can run
multiple VMs efficiently. The Dalvik VM executes files in the Dalvik Executable
(.dex) format which is optimized for minimal memory footprint. The VM is
register-based, and runs classes compiled by a Java language compiler that have
been transformed into the .dex format by the included "dx" tool.
The Dalvik VM relies on the Linux kernel for underlying functionality such as
threading and low-level memory management.
Linux Kernel
Android relies on Linux version 2.6 for core system services such as
security, memory management, process management, network stack, and driver
model. The kernel also acts as an abstraction layer between the hardware and the
rest of the software stack.
참고
http://developer.android.com/guide/basics/what-is-android.html
SKT 에서도 Web Store 사업을 시작하였다..
