android studio java.lang.NoClassDefFoundError Gson

Question

I've made pretty much a fresh project. I added in the gson library by google to my projects /libs directory and added it as a library. I also added it into my build.gradle as

compile files('libs/gson-2.2.4.jar')

So now everything looks ok, there aren't any errors given by Android Studio, no red underlines anywhere. I can build it and give it a shot.

But then I run into this error:

java.lang.NoClassDefFoundError: com.google.gson.Gson

Which I can see in the debugger. The thing is i've added it in and android studio can see that but come build it gives me all these sorts of problems.

What am I doing wrong?

Answer 1

Had the same issue. What I did was gradle clean and then build my project with gradle from console. In my build.gradle gson dependency looks like this:

dependencies {
    compile 'com.google.code.gson:gson:2.2.4'
}

Answer 2

Something went wrong in incremental build system. One of this should help:

1. Menu Build -> Rebuild project
2. Delete folder /build
3. Close Android Studio, delete /build folder
4. Right click on your project -> "Open module settings" -> Dependencies tab -> check if Export is checked for your library

Answer 3

I'm using Android Studio. and in my case, gradle clean and/or Rebuild project didn't work. I had to uninstall the current SDK (in my case: 22) that was supposed to be corrupted and then reinstall it. After doing this, the project restarted to compile and run. Hope it can help someone.