How to use a jar file obtained from apk conversion using dex2jar in another Android project?

Question

I have an apk file of an android app, which I convert to a jar file using dex2jar. Now, I would like to use this jar file in another Android project.

To do so, I use provided files('libs/filename.jar') in my build.gradle file. However, when trying to build my Android project I keep getting the following error.

Failed to create MD5 hash for file 'pathToJar'

I am wondering if anyone has any idea why I am getting this error?

Answer 1

The most probable reason for this might be your instant run feature is enabled. You might consider checking if the instant run is enabled. If it is enabled, please disable the instant run and try to build the project again.

File -> Settings -> Build, Execution & Deplyment -> Disable Instant Run

Now clean your project and rebuild. Hope that helps!

Answer 2

The jar file you got is from another application. To prevent reverse engineering and fraud usage, the developers of this jar file probably used MAC or simple hash check. IMO this is checking the package name in which the jar is placed.

You can try changing the package name similar to that from which you got this jar (reverse engineered). I honestly do not recommend you do such practices.