Architecture of Android, what it?
Information on architecture of Android will hardly interest the readers who are not connected with programming, but nevertheless I cannot disregard this subject. Android - it is a program stack for mobile devices which includes an operating system, the software of an intermediate layer (middleware), and also the main user applications (e - mail - the client, a calendar, cards, the browser, contacts and others).
Architecture of Android is constructed on the basis of version 2 Linux kernel. 6. It is responsible for such system services as management of safety, memory, processes, includes a network stack and model of drivers. Besides, this kernel also plays a role of an abstract layer between the hardware level and other part of a program stack.
the Following level in the hierarchical &ndash system; the libraries written on C/C ++. In media libraries (Media Libraries) support of the main formats and codecs, including MPEG4, H is put. 264, MP3, WMA, WAV, AAC, AMR, JPG, PNG. Graphic libraries (3D Libraries) support API OpenGL ES 1. 0 also provide support of equipment rooms 3D - accelerators. As it is noted, in one appendix it is possible to use at the same time two - and three-dimensional graphics. One more remarkable library is LibWebCore (WebKit) - a cursor for web - the Android browser, used also in the popular Safari browser from Apple.
of One of the most important parts of a stack is Android Runtime consisting of virtual Java - the Dalvik car and a set of libraries of a kernel. Dalvik allows to support simultaneous work of several appendices and carries out files in a special format. dex optimized for devices with small amount of memory. Libraries of a kernel are written in the Java language and include a big set of classes which support the wide range of functionality.
Following &ndash level; Application Framework (framework of appendices). This level actually represents tools which all appendices use. Here it is worth allocating such component as Content Providers (providers of data) which is unique feature of Android. Providers of data allow to unite, for example, information from the Internet with data of &ndash phone; contact information or geographical location, - to realize new functions. Besides, data can be shared by different appendices.
I, at last, at pyramid top - level of appendices (Applications). What is interesting, Android does not do a difference between the main applications of phone and the third-party software - thus, key components, such as number set, a desktop or the Gmail e-mail client, it is possible to replace with alternative analogs. Applications for Android are written in the Java language.