How to extract code of .apk file which is not working? [duplicate]

Question

Actually I was trying to extract code of a .apk file called cloudfilz.apk and wanted to manipulate in its source code so I followed the steps given below:-

make a new folder and put .apk file (which you want to decode) now rename this .apk file with extension .zip (eg: rename from filename.apk to filename.apk.zip) and save it..now you get classes.dex files etc...at this stage you are able to see drawable but not XML and java file...so continue...

Step 2:

now extract this zip apk file in the same folder(in this eg or case NEW FOLDER). now download dex2jar from this link http://code.google.com/p/dex2jar/ and extract it to the same folder (in this case NEW FOLDER).....now open command prompt and reach to that folder (in this case NEW FOLDER)....after reaching write "dex2jar classes.dex" and press enter.....now you get classes.dex.dex2jar file in the same folder......

=>Question:-I was successful to achieve step 1 but in step2 when I am executing dex2jar classes.dex I am getting an error on command prompt java.lang.UnsupportedClassVersionError ,I know this is due to incompatibility between my installed JDK version and classes.dex JDK version number so stuck here and don't have way out...

Alathia

If the author of that application wanted you to see the source, he/she would have published it as Open Source. My guess is it's not open source and you have no right to try and extract it. – Factual

@Factual Sometimes you want to know why a particular app on your new Android phone (CMAS) has WAY more rights than it should. --------------------------------- “I am a firm believer in the people. If given the truth, they can be depended upon to meet any national crisis. The great point is to bring them the real facts, and beer.” ― Abraham Lincoln --------------------------------- – Abe

technikes.com/find-a-source-code-from-apk-file two new steps for your question – Woolworth

Answer 1

Any .apk file from market or unsigned

1. If you apk is downloaded from market and hence signed Install Astro File Manager from market. Open Astro > Tools > Application Manager/Backup and select the application to backup on to the SD card . Mount phone as USB drive and access 'backupsapps' folder to find the apk of target app (lets call it app.apk) . Copy it to your local drive same is the case of unsigned .apk.

2. Download Dex2Jar zip from this link: SourceForge

3. Unzip the downloaded zip file.

4. Open command prompt & write the following command on reaching to directory where dex2jar exe is there and also copy the apk in same directory.

   dex2jar targetapp.apk file(./dex2jar app.apk on terminal)

5. http://jd.benow.ca/ download decompiler from this link.

6. Open ‘targetapp.apk.dex2jar.jar’ with jd-gui File > Save All Sources to sava the class files in jar to java files.

Alathia

i will try this,.......... – Simmer

Answer 2

Note: All of the following instructions apply universally (aka to all OSes) unless otherwise specified.

---

Prerequsites

You will need:

• A working Java installation
• A working terminal/command prompt
• A computer
• An APK file

Steps

Step 1: Changing the file extension of the APK file

1. Change the file extension of the .apk file by either adding a .zip extension to the filename, or to change .apk to .zip.

   For example, com.example.apk becomes com.example.zip, or com.example.apk.zip. Note that on Windows and macOS, it may prompt you whether you are sure you want to change the file extension. Click OK or Add if you're using macOS:

Step 2: Extracting Java files from APK

1. Extract the renamed APK file in a specific folder. For example, let that folder be demofolder.

   • If it didn't work, try opening the file in another application such as WinZip or 7-Zip.

   • For macOS, you can try running unzip in Terminal (available at /Applications/Terminal.app), where it takes one or more arguments: the file to unzip + optional arguments. See man unzip for documentation and arguments.

2. Download dex2jar (see all releases on GitHub) and extract that zip file in the same folder as stated in the previous point.

3. Open command prompt (or a terminal) and change your current directory to the folder created in the previous point and type the command d2j-dex2jar.bat classes.dex and press enter. This will generate classes-dex2jar.jar file in the same folder.

   • macOS/Linux users: Replace d2j-dex2jar.bat with d2j-dex2jar.sh. In other words, run d2j-jar2dex.sh classes.dex in the terminal and press enter.

4. Download Java Decompiler (see all releases on Github) and extract it and start (aka double click) the executable/application.

5. From the JD-GUI window, either drag and drop the generated classes-dex2jar.jar file into it, or go to File > Open File... and browse for the jar.

6. Next, in the menu, go to File > Save All Sources (Windows: Ctrl+Alt+S, macOS: ⌘+⌥+S). This should open a dialog asking you where to save a zip file named `classes-dex2jar.jar.src.zip" consisting of all packages and java files. (You can rename the zip file to be saved)

7. Extract that zip file (classes-dex2jar.jar.src.zip) and you should get all java files of the application.

Step 3: Getting xml files from APK

• For more info, see the apktool website for installation instructions and more

• Windows:

  1. Download the wrapper script (optional) and the apktool jar (required) and place it in the same folder (for example, myxmlfolder).
  2. Change your current directory to the myxmlfolder folder and rename the apktool jar file to apktool.jar.
  3. Place the .apk file in the same folder (i.e myxmlfolder).

  4. Open the command prompt (or terminal) and change your current directory to the folder where apktool is stored (in this case, myxmlfolder). Next, type the command apktool if framework-res.apk.

     What we're doing here is that we are installing a framework. For more info, see the docs.

  5. The above command should result in "Framework installed ..."

  6. In the command prompt, type the command apktool d filename.apk (where filename is the name of apk file). This should decode the file. For more info, see the docs.

     This should result in a folder filename.out being outputted, where filename is the original name of the apk file without the .apk file extension. In this folder are all the XML files such as layout, drawables etc.

Source: How to get source code from APK file - Comptech Blogspot

Lixiviate

its worked for me to generate xml files. – Doctorate

better link to JD-GUI is: jd.benow.ca – Crispy

"Now open command prompt and go to the folder created in previous step and type the command "dex2jar classes.dex" and press enter.This will generate "classes.dex.dex2jar" file in the same folder." There is no bat file in the github link – Feculent

Ubuntu users, move both 'apktool' and 'apktool.jar' files to '/usr/local/bin' folder. Open the terminal path pointing to the apk folder location type apktool d <your-app-name.apk> – Deposal

I've updated the instructions since some URLs were broken. – Masturbation

In step 3 you put d2j-jar2dex.bat classes.dex i think this is meant to be d2j-dex2jar.bat classes.dex Dex > Jar – Wingate

@DutA. Looks like that just points to java-decompiler.github.io now, maybe it should be moved again? (The old domain might expire) – Wye

Answer 3

step 1:

Download dex2jar here. Create a java project and paste (dex2jar-0.0.7.11-SNAPSHOT/lib ) jar files .

Copy apk file into java project

Run it and after refresh the project ,you get jar file .Using java decompiler you can view all java class files

step 2: Download java decompiler here

Brachy

Thanks Sony for response but i am not able to fetch jar file so please can u explain in detail...ur screen shot is showing that your dex2jar lib jar files another location but it should be saved inside java project how its feasible..please clear my ambiguity.. – Alathia

just you copy dext2jar lib jar files in java project ,not src folder – Brachy

I have put apk file into src. & What is the Main class ? is it this com.googlecode.dex2jar.dump.Dump? – Deathbed

is the procedure same for linux users??? – Invention

Answer 4

Click here this is a good tutorial for both window/ubuntu.

1. apktool1.5.1.jar download from here.

2. apktool-install-linux-r05-ibot download from here.

3. dex2jar-0.0.9.15.zip download from here.

4. jd-gui-0.3.3.linux.i686.tar.gz (java de-complier) download from here.

5. framework-res.apk ( Located at your android device /system/framework/)

Procedure:

1. Rename the .apk file and change the extension to .zip ,

it will become .zip.

2. Then extract .zip.

3. Unzip downloaded dex2jar-0.0.9.15.zip file , copy the contents and paste it to unzip folder.

4. Open terminal and change directory to unzip “dex2jar-0.0.9.15 “

– cd – sh dex2jar.sh classes.dex (result of this command “classes.dex.dex2jar.jar” will be in your extracted folder itself).

5. Now, create new folder and copy “classes.dex.dex2jar.jar” into it.

6. Unzip “jd-gui-0.3.3.linux.i686.zip“ and open up the “Java Decompiler” in full screen mode.

7. Click on open file and select “classes.dex.dex2jar.jar” into the window.

8. “Java Decompiler” and go to file > save and save the source in a .zip file.

9. Create “source_code” folder.

10. Extract the saved .zip and copy the contents to “source_code” folder.

11. This will be where we keep your source code.

12. Extract apktool1.5.1.tar.bz2 , you get apktool.jar

13. Now, unzip “apktool-install-linux-r05-ibot.zip”

14. Copy “framework-res.apk” , “.apk” and apktool.jar

15. Paste it to the unzip “apktool-install-linux-r05-ibot” folder (line no 13).

16. Then open terminal and type:

    – cd

    – chown -R : ‘apktool.jar’

    – chown -R : ‘apktool’

    – chown -R : ‘aapt’

    – sudo chmod +x ‘apktool.jar’

    – sudo chmod +x ‘apktool’

    – sudo chmod +x ‘aapt’

    – sudo mv apktool.jar /usr/local/bin

    – sudo mv apktool /usr/local/bin

    – sudo mv aapt /usr/local/bin

    – apktool if framework-res.apk – apktool d .apk

Drin