What technologies are needed for Android development?

I. Application program

Android uses Java as the programming language, which makes the interface and functions change endlessly. Among them, Activity is equivalent to J2ME's MIDlet, an Activity class is responsible for creating windows, an Activity is in foreground mode, and the program running in the background is called Service.

Second, the intermediary software

The communication bridge between operating system and application is divided into two layers: functional layer and virtual machine. Bionic is an improved version of libc for Android.

Android also includes Webkit, which is the engine behind AppleSafari browser. Surfaceflinger displays 2D or 3D content on the screen. Android uses Google's homemade BionicLibc tool chain.

Third, the hardware extraction layer

HAL (Hardware Abstraction Layer) of Android can provide hardware driver module in the form of closed source code. Hardware abstraction layer (abbreviation of hardware abstraction layer)

The purpose of is to separate Androidframework from Linuxkernel.

Let Android not rely too much on Linux.

Kernel, which realizes the concept of kernelindependent, also makes Androidframework.

The development of can not consider the implementation of the driver.

Fourth, programming language.

Android runs on Linuxkernel, but it is not GNU/Linux. Because most of the functions supported by GNU/Linux are not supported by Android.

Including Cairo, X 1 1, Alsa, FFmpeg, GTK, Pango and Glibc have all been deleted. Android uses bionic instead of Glibc, Cairo uses Skia, and FFmpeg uses opencore.

Verb (abbreviation of verb) security guarantee

At present, Linux kernel control of Android includes security, memory management, process management, network stack, driver model and so on.

Before downloading the Android source code, you should install its build tool Repo to initialize the source code. Repo is a tool used by Android to assist Git.