Java finished with non-zero exit value 2 - Android Gradle

Question

I\'m getting this error executing my Android app (I cleaned it and then built it, but the error is still present)

• Sync: OK
• Make Project: OK

Answer 1

In my case, the problem was that the new library (gradle dependency) that I had added was relying on some other dependencies and two of those underlying dependencies were conflicting/clashing with some dependencies of other libraries/dependencies in my build script. Specifically, I added Apache Commons Validator (for email validation), and two of its dependencies (Apache Commons Logging and Apache Commons Collections) were conflicting with those used by Robolectric (because different versions of same libraries were present in my build path). So I excluded those conflicting versions of dependencies (modules) when adding the new dependency (the Validator):

compile ('commons-validator:commons-validator:1.4.1') {
    exclude module: 'commons-logging'
    exclude module: 'commons-collections'
}

You can see the dependencies of your gradle module(s) (you might have only one module in your project) using the following gradle command (I use the gradle wrapper that gets created for you if you have created your project in Android Studio/Intellij Idea). Run this command in your project's root directory:

./gradlew :YOUR-MODULE-NAME:dependencies

After adding those exclude directives and retrying to run, I got a duplicate file error for NOTICE.txtthat is used by some apache commons libraries like Logging and Collections. I had to exclude that text file when packaging. In my build.gradle, I added:

packagingOptions {
    exclude 'META-INF/NOTICE'
    exclude 'META-INF/notice.txt'
    exclude 'META-INF/NOTICE.txt'
}

It turned out that the new library (the Validator) can work with slightly older versions of its dependencies/modules (which are already imported into my build path by another library (Robolectric)). This was the case with this specific library, but other libraries might be using the latest API of the underlying dependencies (in which case you have to try to see if the other libraries that rely on the conflicting module/dependency are able to work with the newer version (by excluding the older version of the module/dependecy under those libraries's entries)).