Android phones, like the Galaxy Nexus
, allow installation of applications directly via APK files or indirectly via Google Play
Android application package file (APK) is the file format used to distribute and install application software and middleware onto Google's Android operating system. To make an APK file, a program for Android is first compiled, and then all of its parts are packaged into one file. An APK file contains all of that program's code (such as .dex files), resources, assets, certificates, and manifest file. As is the case with many file formats, APK files can have any name needed, provided that the file name ends in ".apk".
APK files are ZIP file formatted packages based on the JAR file format, with
.apk file extensions. The MIME type associated with APK files is
An APK file is an archive that usually contains the following folders:
MANIFEST.MF: the Manifest file
CERT.RSA: The certificate of the application.
CERT.SF: The list of resources and SHA-1 digest; for example:
Created-By: 1.0 (Android)
lib: the directory containing the compiled code that is specific to a software layer of a processor, the folder is split into more folders within it:
armeabi: compiled code for all ARM based processors only
armeabi-v7a: compiled code for all ARMv7 and above based processors only
x86: compiled code for x86 processors only
mips: compiled code for MIPS processors only
res: the directory containing resources not compiled into resources.arsc (see below).
assets: a directory containing applications assets, which can be retrieved by
AndroidManifest.xml: An additional Android manifest file, describing the name, version, access rights, referenced library files for the application. This file may be in Android binary XML that can be converted into human-readable plaintext XML with tools such as AXMLPrinter2, apktool, or Androguard.
classes.dex: The classes compiled in the dex file format understandable by the Dalvik virtual machine
resources.arsc : a file containing pre-compiled resources, such as binary XML for example.
See also