DuplicateFileException error while building Android APK

Question

I am using Android Studio 2.0 on Windows 7. When building my Android project, I get the following error:

:app:transformResourcesWithMergeJavaResForDebug FAIL         


        

Answer 1

To complete @dsh's answer:

In your dependency tree there are 2 jar files containing the same file named sep_approx_spanish.txt , this is not allowed.

To resolve your problem you have to track down which of your gradle dependencies has the two jars named appengine-api-1.0-sdk-1.9.28.jar and appengine-endpoints-1.9.28.jar; to do this you can open android studio's terminal console and type in:

//if ou are on windows
gradlew dependencies

//if you are on unix based os
./gradlew dependencies

You will see gradle doing a lot of things, but at a certain point it will print the entire dependency tree. Once you find which are the 2 dependencies are causing the problem, add this piece of code at the end of one of the dependency declarations

{
    exclude "sep_approx_spanish.txt"
}

So for example if the two dependencies are these

compile 'com.google.appengine:appengine-endpoints:1.9.28'
compile 'com.google.appengine:appengine-endpoints-deps:1.9.28

if must become

compile 'com.google.appengine:appengine-endpoints:1.9.28'{
        exclude "sep_approx_spanish.txt"
    }
 compile 'com.google.appengine:appengine-endpoints-deps:1.9.28

or

compile 'com.google.appengine:appengine-endpoints:1.9.28'
compile 'com.google.appengine:appengine-endpoints-deps:1.9.28'{
        exclude "sep_approx_spanish.txt"
    }

in this way you tell to gradle to not take into consideration that file for one of the two libraries, avoiding the file's duplication inside the apk.

Answer 2

Completing @Apperside answer.

I fixed the error by adding the following lines to my build.gradle file of my app module:

android{

    packagingOptions {
            exclude 'com/google/appengine/repackaged/org/apache/commons/codec/language/bm/*'
            exclude 'com/google/appengine/repackaged/org/codehaus/jackson/impl/VERSION.txt'
            exclude 'com/google/appengine/repackaged/org/apache/commons/codec/language/*'
        }

    (...)  
}

Answer 3

The error tells you that building your APK would result in two files named com/google/appengine/repackaged/org/apache/commons/codec/language/bm/sep_approx_spanish.txt. This is a failure because the APK can only contain one file at any given path. This is probably caused by two different jar files in your classpath that contain the file. In my project, this only occurred with files that were not actually used at runtime so I excluded them from the APK entirely.