Reverse engineering from an APK file to a project

Question

I accidently erased my project from Eclipse, and all I have left is the APK file which I transferred to my phone. Is there a way to reverse the process of exporting an application to the .apk file, so I can get my project back?

Answer 1

There are two useful tools which will generate Java code (rough but good enough) from an unknown APK file.

1. Download dex2jar tool from dex2jar.

2. Use the tool to convert the APK file to JAR: Windows:

    $ d2j-dex2jar.bat demo.apk
    dex2jar demo.apk -> ./demo-dex2jar.jar
   

   MacOS / Linux:

    $ d2j-dex2jar.sh -f demo.apk -o demo.jar
   

3. Once the JAR file is generated, use JD-GUI to open the JAR file. You will see the Java files.

The output will be similar to:

Then you can use other tools to retrieve the AndroidManifest.xml and resource files (like images, translations, etc...) from the APK file.

• Apktool

   $ java -jar apktool.jar -q decode -f demo.apk -o outputDir
  

• AXMLParser

   $ apkinfo demo.apk
  

• NinjaDroid

   $ ninjadroid demo.apk --all --extract
  

Answer 2

First of all I recommend this video may this is clears all yours doubts

If not please go through it

Procedure for decoding .apk files, step-by-step method:

Step 1:

Make a new folder and put .apk file in it (which you want to decode). Now rename the extension of this .apk file to .zip (eg.: rename from filename.apk to filename.zip) and save it.

If problems in the converting into .zip please refers link

After getting .zip now you get classes.dex files, etc. At this stage you are able to see drawable but not xml and java files, so continue. If you don’t see the extensions go through check the configuration

Step 2:

Now extract this zip apk file in the same folder. Now download dex2jar from this link

and extract it to the same folder. Now open command prompt and change directory to that folder.

Then write dex2jar classes.dex and press enter. Now you get classes.dex.dex2jar file in the same folder.

Then download java decompiler

And now double click on jd-gui and click on open file. Then open classes.dex.dex2jar file from that folder. Now you get class files and save all these class files (click on file then click "save all sources" in jd-gui) by src name. Extract that zip file (classes_dex2jar.src.zip) and you will get all java files of the application.

At this stage you get java source but the xml files are still unreadable, so continue.

Step 3:

Now open another new folder and put these files

1. put .apk file which you want to decode

2. download Apktool for windows v1.x And Apktool

install window using google and put in the same folder

3. download framework-res.apk file using google and put in the same folder (Not all apk file need framework-res.apk file)

4. Open a command window

5. Navigate to the root directory of APKtool and type the following command: apktool if framework-res.apk.

Above command should result in Framework installed ....

6. apktool d "appName".apk ("appName" denotes application which you want to decode) now you get a file folder in that folder and now you can easily read xml files also.

Step 4: Finally we got the res/ as well as java code of project which is our target at starting.

P.S. If you are not able to get res folder by above steps please do install new apktool

• Is Java 1.7 installed? Install Apktool 2.x
• Is Java 1.6 or higher installed? Install Apktool 1.x

Enjoy and happy coding

Answer 3

No software & No too much steps..

Just upload your APK & get your all resources from this site..

https://www.apkdecompilers.com/

This website will decompile the code embedded in APK files and extract all the other assets in the file.

note: I decompile my APK file & get code within one miniute from this website

Update 1:

I found another online decompiler site,

http://www.javadecompilers.com/apk/ - Not working continuously asking for popup blocking

Update 2:

I found apk decompiler app in play store,

https://play.google.com/store/apps/details?id=com.njlabs.showjava

We can decompile the apk files in our android phone. and also we can able to view the java & xml files in this application

Update 3:

We can use another option Analyze APK feature from Android studio 2.2 version

Build -> Analyze APK -> Select your APK -> it give results

Answer 4

There is a new way to do this.

Android Studio 2.2 has APK Analyzer it will give lot of info about apk, checkout it here :- http://android-developers.blogspot.in/2016/05/android-studio-22-preview-new-ui.html

Answer 5

In Android Studio 3.5, It's soo easy that you can just achieve it in a minute. following is a step wise process.

1: Open Android Studio, Press window button -> Type Android Studio -> click on icon to open android studio splash screen which will look like this.

2: Here you can see an option "Profile or debug APK" click on it and select your apk file and press ok.

3: It will open all your manifest and java classes with in a minute depending upon size of apk.

That's it.

Answer 6

Not really. There are a number of dex disassembler/decompiler suites out there such as smali, or dex2jar that will generate semi-humanreadable output (in the case of dex2jar, you can get java code through the use of something like JD-GUI but the process is not perfect and it is very unlikely that you'll be able to 100% recreate your source code. However, it could potentially give you a place to start rebuilding your source tree.

Answer 7

Yes, you can get your project back. Just rename the yourproject.apk file to yourproject.zip, and you will get all the files inside that ZIP file. We are changing the file extension from .apk to .zip. From that ZIP file, extract the classes.dex file and decompile it by following way.

First, you need a tool to extract all the (compiled) classes on the DEX to a JAR. There's one called dex2jar, which is made by a Chinese student.

Then, you can use JD-GUI to decompile the classes in the JAR to source code. The resulting source code should be quite readable, as dex2jar applies some optimizations.

Answer 8

For the Android platform, you can try ShowJava, available on the Play Store.

You can consult the generated code through the app interface and the generated java files and folders structure are stored in ShowJava folder in /sdcard, alongside the resulting .jar file from the conversion.

The app is free with an ad banner at the bottom of the main view, but there is an in-app purchase option (3,99$) to remove it. In-app purchase does not add any functionality beside removing the ad banner.

Disclosure : I'm not the developer of the app neither I'm affiliated with him in any way.

Answer 9

Try this tool: https://decompile.io, it runs on iPhone/iPad/Mac

Answer 10

Follow below steps to do this or simply use apkToJava gem for this process, it even takes care of installing the required tools for it to work.

• convert apk file to zip
• unzip the file
• extract classes.dex from it
• use dex to jar to convert classes.dex into jar file
• use jadx gui to open the jar file as java source code

Answer 11

If you are looking for a professional alternative, have a look at JEB Decompiler from PNF Software.

There is a demo version that will let you decompile most code.

Answer 12

Below are some of the tools which you can use to perform reverse engineering from an APK file to source code :

1. Dex2jar
2. Java decompiler
3. Apktool
4. Apk Analyser

Answer 13

Another tool that you may want to use is APK Studio It relies howewer on third party tools: Apktool, jadx, ADB and Uber APK signer that you need to download separately.