APK is the abbreviation of Android Package, which is the Android installation package. APK is a file format similar to Symbian Sis or Sisx. You can install it by directly transferring the APK file to the Android emulator or Android phone for execution. The APK file is actually in zip format, but the suffix name is changed to apk. After decompressing it through UnZip, you can see the Dex file. Dex is the full name of Dalvik VM executes, which is the Android Dalvik execution program. It is not the bytecode of Java ME but the Dalvik bytecode.
The structure of an APK file is:
mete-INF Jar files can often see
res directory where resource files are stored
AndroidManifest. xml program global configuration file
classes. dex Dalvik bytecode
resources. arsc Compiled binary resource file
In summary, we found that Android first needs UnZip when running a program, and then it is as direct as Symbian, which is different from the PE file in Windows Mobile. This is not very confidential and reliable for the program. It can be decompiled through the dexdump command, but this is in line with the law of development. Microsoft's Windows Gadgets or WPF also uses this architecture.
In the Android platform, the executable file of dalvik vm is packaged in apk format, and the final runtime loader will decompress and obtain the compiled androidmanifest. Security access related to the permission branch in the xml file, but there are still many security restrictions. If you transfer the apk file to the /system/app folder, you will find that the execution is unrestricted. In the end, the files we usually install may not be in this folder, and the system apk files in android rom will be placed in this folder by default, and they have root permissions.
