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android – Is there a way to get the source code from an APK file?

Posted by: admin March 10, 2020 Leave a comment

Questions:

The hard drive on my laptop just crashed and I lost all the source code for an app that I have been working on for the past two months.
All I have is the APK file that is stored in my email from when I sent it to a friend.

Is there any way to extract my source code from this APK file?

How to&Answers:

Simple way: use online tool http://www.javadecompilers.com/apk, upload apk and get source code.


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

Step 1:

  1. Make a new folder and copy over the .apk file that you want to decode.

  2. Now rename the extension of this .apk file to .zip (e.g. rename from filename.apk to filename.zip) and save it. Now you can access the classes.dex files, etc. At this stage you are able to see drawables but not xml and java files, so continue.

Step 2:

  1. Now extract this .zip file in the same folder (or NEW FOLDER).

  2. Download dex2jar and extract it to the same folder (or NEW FOLDER).

  3. Move the classes.dex file into the dex2jar folder.

  4. Now open command prompt and change directory to that folder (or NEW FOLDER). Then write d2j-dex2jar classes.dex (for mac terminal or ubuntu write ./d2j-dex2jar.sh classes.dex) and press enter. You now have the classes.dex.dex2jar file in the same folder.

  5. Download java decompiler, double click on jd-gui, click on open file, and open classes.dex.dex2jar file from that folder: now you get class files.

  6. Save all of these class files (In jd-gui, click File -> Save All Sources) by src name. At this stage you get the java source but the .xml files are still unreadable, so continue.

Step 3:

Now open another new folder

  1. Put in the .apk file which you want to decode

  2. Download the latest version of apktool AND apktool install window (both can be downloaded from the same link) and place them in the same folder

  3. Open a command window

  4. Now run command like apktool if framework-res.apk (if you don’t have it get it here)and next

  5. apktool d myApp.apk (where myApp.apk denotes the filename that you want to decode)

now you get a file folder in that folder and can easily read the apk’s xml files.

Step 4:

It’s not any step, just copy contents of both folders(in this case, both new folders) to the single one

and enjoy the source code…

Answer:

This is an alternative description – just in case someone got stuck with the description above. Follow the steps:

  1. download apktool.bat (or apktool for Linux) and apktool_<version>.jar from http://ibotpeaches.github.io/Apktool/install/
  2. rename the jar file from above to apktool.jar and put both files in the same folder
  3. open a dos box (cmd.exe) and change into that folder; verify that a Java Environment is installed (for Linux check the notes regarding required libraries as well)
  4. Start: apktool decode [apk file]

    Intermediate result: resource files, AndroidManifest.xml

  5. unzip APK file with an unpacker of your choice

    Intermediate result: classes.dex

  6. download and extract dex2jar-0.0.9.15.zip from http://code.google.com/p/dex2jar/downloads/detail?name=dex2jar-0.0.9.15.zip&can=2&q=
  7. drag and drop classes.dex onto dex2jar.bat (or enter <path_to>\dex2jar.bat classes.dex in a DOS box; for Linux use dex2jar.sh)

    Intermediate result: classes_dex2jar.jar

  8. unpack classes_dex2jar.jar (might be optional depending on used decompiler)
  9. decompile your class files (e.g. with JD-GUI or DJ Decompiler)

    Result: source code

Note: it is not allowed to decompile third party packages; this guide is intended to recover personal source code from an APK file only; finally, the resulting code will most likely be obfuscated

Answer:

While you may be able to decompile your APK file, you will likely hit one big issue:

it’s not going to return the code you wrote. It is instead going to return whatever the compiler inlined, with variables given random names, as well as functions given random names. It could take significantly more time to try to decompile and restore it into the code you had, than it will be to start over.

Sadly, things like this have killed many projects.
For the future, I highly recommend learning a Version Control System, like CVS, SVN and git etc.

and how to back it up.

Answer:

There is also a new application on the Play Store with which it is possible to decompile an apk (system applications too) and view the source code right on your smartphone. It saves the files to your SD card so you can view it on your computer too. It does not require root or something else.

Just install and have fun. I think this is the easiest way to decompile an app.

Answer:

apktool is the best thing you can try. I have saved some xml with it, but honestly I don’t know how it will work with the .java code.

I would recommend you to have a code repository even if your are the only coder. I’ve been using Project Locker for my own projects. It gives you free svn and git repos.

Answer:

These two articles describe how to combine the use of apktool and dex2jar to take an APK file and create an Eclipse project that can build and run it.

http://blog.inyourbits.com/2012/11/extending-existing-android-applications.html

http://blog.inyourbits.com/2012/12/extending-existing-android-applications.html

Basically you:

  1. Use apktool to get the resource files out of the apk
  2. Use dex2jar to get a jar file that contains the classes in a format that Eclipse will like.
  3. Create an Eclipse project point it at the resource files and the new jar file
  4. Open the jar file with a zip utility and delete the existing resources
  5. Open the jar file with JDGui to view the source code
  6. Take whatever source code you need from JDGui, stick it in a class inside Eclipse and modify it
  7. Delete that class from the jar file (so you don’t have the same class defined multiple times)
  8. Run it.

Answer:

apktool will work. You don’t even need to know the keystore to extract the source code (which is a bit scary). The main downside is that the source is presented in Smali format instead of Java. Other files such as the icon and main.xml come through perfectly fine though and it may be worth your time to at least recover those. Ultimately, you will most likely need to re-write your Java code from scratch.

You can find apktool here. Simply just download apktool and the appropriate helper (for Windows, Linux, or Mac OS). I recommend using a tool such as 7-zip to unpack them.

Answer:

May be the easy one to see the source:

In Android studio 2.3, Build -> Analyze APK -> Select the apk that you want to decompile.
You will see it’s source code.

Link for reference:
https://medium.com/google-developers/making-the-most-of-the-apk-analyzer-c066cb871ea2

Answer:

There are a few ways to do this:

  1. Use the “Profile or Debug APK” feature in Android Studio 3.0.

    It allows you to open and explore APKs in Android Studio. Classes are decompiled into smali. Resources are not extracted and things like “Go to Definition”, “Find All References” and debugging don’t work without the source code (android studio 3.0 canary 9). Some additional smali features might work with smalidea.

    android-studio

    select-file

    code

  2. Use jadx.

    Jadx decompiles the code in a given APK to java source files.

    jdax-img

  3. Use apktool.

    Apktool is a command line tool which extracts resources and decompiles code into smali for a given apk. You can recompile using apktool also. Here’s an example of it in action:

    $ apktool d test.apk
    I: Using Apktool 2.2.4 on test.apk
    I: Loading resource table...
    I: Decoding AndroidManifest.xml with resources...
    I: Loading resource table from file: 1.apk
    I: Regular manifest package...
    I: Decoding file-resources...
    I: Decoding values */* XMLs...
    I: Baksmaling classes.dex...
    I: Copying assets and libs...
    I: Copying unknown files...
    I: Copying original files...
    $ apktool b test
    I: Using Apktool 2.2.4 on test
    I: Checking whether sources has changed...
    I: Smaling smali folder into classes.dex...
    I: Checking whether resources has changed...
    I: Building resources...
    I: Building apk file...
    I: Copying unknown files/dir...
    

Answer:

I’ll show you other way to decompile the .apk files.

You can follow the first 2 steps from “prankul garg“. So you have another opportunities:

Step 3′:

Download the “JD-GUI”, thats easy to found this one.
Open your .jar file in “jd-gui.exe”. (File > Open file > ‘found your .jar file’). After this procedure, you can save all resources in a .zip file.

So,

1st – You have to rename the .apk file to .zip

2nd – You have to decode .dex file (if you want, decode the .apk file to dex2jar, that’s possible)

3rd – You have to decode .jar file with JD-GUI

Answer:

Below ONLINE tool:

http://www.javadecompilers.com/apk

it do ALL by one click: decompiled .java files + resources + xml (in one .zip file) with very good decompiler (jadx return java code in places/functions where other compiles return comments inside function like “unable to decompile” or some android assembler/machine code)

Answer:

This site https://www.apkdecompilers.com/ did it automatically.

I tried the site mentioned in the accepted answer first but that didn’t work for me.

Answer:

I personally recommend Show Java Android App to get the source code. You can download it from play store or from here

Answer:

Apktool for reverse engineering 3rd party, closed, binary Android apps.

It can decode resources to nearly original form and rebuild them after making some modifications.

It makes possible to debug smali code step by step. Also it makes working with an app easier because of project-like file structure and automation of some repetitive tasks like building apk, etc.

http://ibotpeaches.github.io/Apktool/

Answer:

apktool is THE way to go.
Online apktool service exists as well: http://www.javadecompilers.com/apktool

Some limitations, obviously, exist due to the service ‘online nature’: you may extract and research assets and the manifest file, but it is impossible to recompile the application at the moment.

Still, this is a no-hassle way to ‘open’ the android application.

Answer:

You can try DexPatcher. It even integrates with Android Studio. It uses Apktool and Dex2Jar internally.
You can use those tools independently as well.
Apktool decompiles apk, and extracts .dex files, which can further be converted to jar using Dex2Jar. Jar can be decompiled by using JD-GUI. You can see the Java code with the help of that tool. Although the similarity of decompiled code to the actual code cannot be guaranteed. There are some advanced code obfuscation tools available in the market, which mess up the code to make it difficult to decompile / understand. eg. Proguard

Answer:

based on your condition, if your android apk:

Condition1: NOT harden (by Tencent Legu/Qihoo 360/…)

Choice1: using online service

such as:

using www.javadecompilers.com

goto:

to auto decode from apk to java sourcecode

steps:

upload apk file + click Run + wait some time + click Download to get zip + unzip ->

sources/com/{yourCompanyName}/{yourProjectName}

is your expected java source code

Choice2: decompile/crack by yourself

use related tool to decompile/crack by yourself:

use jadx/jadx-gui convert apk to java sourcecode

download jadx-0.9.0.zip then unzip to got bin/jadx, then:

  • command line mode:
    • in terminal run: jadx-0.9.0/bin/jadx -o output_folder /path_to_your_apk/your_apk_file.apk
    • output_folder will show decoded sources and resources
      • sources/com/{yourCompanyName}/{yourProjectName} is your expected java sourcecode
  • GUI mode
    • double click to run jadx-0.9.0/bin/jadx-gui (Linux’s jadx-gui.sh / Windows’s jadx-gui.bat)
    • open apk file
    • it will auto decoding -> see your expected java sourcecode
    • save all or save as Gradle project

eg:

Condition2: harden (by Tencent Legu/Qihoo 360/…)

the main method of 3 steps:

  1. apk/app to dex
  2. dex to jar
  3. jar to java src

detailed explanation:

Step1: apk/app to dex

use tool (FDex2/DumpDex) dump/hook out (one or multiple) dex file from running app

steps:

prepare environment

dump out dex from running app

  • run FDex2 then click your apk name to enable later to capture/hook out dex

  • (in phone/emulator) run your app
  • find and copy out the dump out whole apk resources in /data/data/com/yourCompanyName/yourProjectName
    • in its root folder normally will find several dex file

Step2: dex to jar

use tool (dex2jar) convert (the specific, containing app logic) dex file to jar file

download dex2jar got dex-tools-2.1-SNAPSHOT.zip, unzip got dex-tools-2.1-SNAPSHOT/d2j-dex2jar.sh, then

sh dex-tools-2.1-SNAPSHOT/d2j-dex2jar.sh -f your_dex_name.dex

eg:

dex-tools-2.1-SNAPSHOT/d2j-dex2jar.sh -f com.xxx.yyy8825612.dex
dex2jar com.xxx.yyy8825612.dex -> ./com.xxx.yyy8825612-dex2jar.jar

Step3: jar to java src

use one of tools:

convert jar to java src

for from jar to java src converting effect:

Jadx > Procyon > CRF >> JD-GUI

so recommend use: Jadx/jadx-gui

steps:

  • double click to run jadx-gui
  • open dex file
  • File -> save all

eg:

exported java src:


More detailed explanation can see my online ebook Chinese tutorial:

Answer:

Android studio offers you to analyse any apk file.

1 – From build menu choose analyse apk option and select apk file.
2 – This will result in you the classes.dex file and other files.
3 – Click on classes.dex which will give you the list of folders, packages, libraries and files.
4 – From and android studio settings install a plugin called “Dex to Jar”
5 – click on any activity file of your extracted project and choose dex to jar from the build menu.

This will result in you the actual code of your java file.

Cheers.

Answer:

The simplest way is using Apk OneClick Decompiler. That is a tool package to decompile & disassemble APKs (android packages).

FEATURES

  • All features are integrated into the right-click menu of Windows.
  • Decompile APK classes to Java source codes.
  • Disassemble APK to smali code and decode its resources.
  • Install APK to phone by right-click.
  • Recompile APK after editing smali code and/or resources.
    During recompile:
  • Optimize png images
  • Sign apks
  • Zipalign

REQUIREMENTS

Java Runtime Environment (JRE) must be installed.

You can download it from this link Apk OneClick Decompiler

Enjoy that.

Answer:

I found the following as the simplest method:

  1. Rename your app.apk to app.zip (Change extension from apk to zip)
  2. Extract the zip file into a folder
  3. Use JADX tool to read the source code, present in classes.dex file.

Answer:

There’s an app for that and generally takes just a few clicks and you are done.
https://github.com/Nuvolect/DeepDive-Android

  1. Select Apps, under “Installed Apps” select your app. If it is not
    there you can load the APK.
  2. Select “Extract APK”
  3. Select “Unpack APK”
  4. Select “Decompile with Jadx”. This can take a few seconds or a few minutes depending
    on the speed of your device

After that you can browse the source code, download it to another computer with elFinder or search through it using Lucene.

In addition to Jadx it has CFR and Fernflower decompilers.

Answer:

I’ve been driving myself crazy for days trying to get dex2jar to work on a fedora 31 laptop against an apk that just wasn’t going to work. This python 3 script did the trick in minutes and installing jd-gui made class files human readable.

http://java-decompiler.github.io/

https://github.com/Storyyeller/enjarify

specifically, here’s what I ran:

# i installed apktool before the rest of the stuff, may not need it but here it is
$> cd /opt
$> sudo mkdir apktool
$> cd apktool/
$> sudo wget https://raw.githubusercontent.com/iBotPeaches/Apktool/master/scripts/linux/apktool
$> sudo wget https://bitbucket.org/iBotPeaches/apktool/downloads/apktool_2.4.1.jar
$> sudo mv apktool_2.4.1.jar apktool.jar
$> sudo mv apktool* /usr/bin/
$> sudo chmod a+x /usr/bin/apktool*

# and enjarify
$> cd /opt
$> sudo git clone https://github.com/Storyyeller/enjarify.git
$> cd enjarify/
$> sudo ln -s /opt/enjarify/enjarify.sh /usr/bin/enjarify

# and finally jd-gui
$> cd /opt
$> sudo git clone https://github.com/java-decompiler/jd-gui.git
$> cd jd-gui/
$> sudo ./gradlew build

# I made an alias to kick of the jd-gui with short commandline rather than long java -jar blahblahblah :)
$> echo "jd-gui='java -jar /opt/jd-gui/build/launch4j/lib/jd-gui-1.6.6.jar'" >> ~/.bashrc

Now one should be able to rum the following to get class files:

$> enjarify yourapkfile.apk

And to start jd-gui:

$> jd-gui

Then just open your class files!