Android project is a software stack for mobile devices including an operating system, middleware and key applications. Developers can create applications for the platform using the Android SDK. Applications are written using the Java programming language and run on Dalvik, a custom virtual machine designed for embedded use which runs on top of a Linux kernel.
If you want to know how to develop applications for Android, you're in the right place. This site provides a variety of documentation that will help you learn about Android and develop mobile applications for the platform.
An early look at the the Android SDK is also available. It includes sample projects with source code, development tools, an emulator, and of course all the libraries you'll need to build an Android application.
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.
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 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.
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.
Here are some key features of "Android SDK":
· 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
What's New in This Release: [ read full changelog ]
The default ProGuard configuration, proguard.cfg, now ignores the following classes:
· classes that extend Preference
· classes that extend BackupAgentHelper
· Ant lib rules now allow you to override java.encoding, java.source, and java.target properties.
· The default encoding for the javac Ant task is now UTF-8.
· The LogCat view in DDMS now properly displays UTF-8 characters.
· The SDK Manager is more reliable on Windows. For details on the improvements, see the Android Tools Project Site.
· If you enabled snapshots for an AVD, they are automatically captured. The emulator also now restores to the state when it last closed almost instantly.
· Fixed the missing JAR file error that prevented draw9patch from running.
· Fixed the Windows launch scripts hierarchyviewer and ddms to support the new location of adb.
· Known issues with emulator performance: Because the Android emulator must simulate the ARM instruction set architecture on your computer, emulator performance is slow.