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androidapkbuild.gradlesignedandroid-proguard

Enabling ProGuard causes failing signed APK generation?

I have enabled minifyEnabled in my gradle file for using the feature of ProGuard to obfuscates code as a result it throwing some error.

  • Note: there were 1 class casts of dynamically created class instances. You might consider explicitly keeping the mentioned classes and/or their implementations (using '-keep').
  • Warning: there were 309 unresolved references to classes or interfaces. You may need to add missing library jars or update their versions. If your code works fine without the missing classes, you can suppress the warnings with '-dontwarn' options. (http://proguard.sourceforge.net/manual/troubleshooting.html#unresolvedclass)

and much more.

I have gone through the ProGuard documentation.i guess this is what happening wrong.am using third party libraries and jars.and it confuses as i have more number of libraries and jars.how can i decide which one should keep in my proguard-rules.pro and which one doesn't ? And what else need to do for using ProGuard successfully and efficiently ?

Solution

  • ProGuard analyzes all the code in your application (that includes libraries) and generates warnings if it sees unresolved references (or other problems, but unresolved references is the important thing here). It is very common for libraries to refer to system or library code that doesn't exist in your project.

    For example: Picasso optionally integrates with OkHttp, and has code referring to that library. But if you haven't included OkHttp ProGuard will warn about unresolved references.

    A successful build must not have any warnings from ProGuard. ProGuard also checks for reflection, if there are unresolved references found in reflection, ProGuard will generate notes instead of warnings. Both warnings and notes may point to issues with the classpath. You could check the code yourself to see if there's an actual problem, or trust the libraries that their code works on Android (and on your target platform version).

    Kevin Schultz opened up a public collection of ProGuard configuration files. His blogpost should help you get started with your configuration file. http://www.kevinrschultz.com/blog/2014/02/15/proguard-with-gradle/

    Do double check the configurations that you copy. They can be a little aggressive sometimes. If possible you want to avoid -dontwarn/dontnote {entire-package} and instead narrow down on the actual problems.