Gradle puts duplicate files in the apk file

Question

I'm using gradle 1.10 and the version of the android plugin is 0.8.0. My android projects needs these two jars: jackson-core-asl-1.9.11.jar and jackson-mapper-asl-1.9.11.jar. I add the files thus:

dependencies {
    compile files('libs/jackson-core-asl-1.9.11.jar')
    compile files('libs/jackson-mapper-asl-1.9.11.jar')
}

During gradle build I get an error message saying that these two files are duplicated in META-INF/ASL2.0. I solved the problem by excluding the following files:

packagingOptions {
       exclude 'META-INF/ASL2.0'
       exclude 'META-INF/LICENSE'
       exclude 'META-INF/NOTICE'
       exclude 'META-INF/LICENSE.txt'
       exclude 'META-INF/NOTICE.txt'
       exclude 'META-INF/notice.txt'
       exclude 'META-INF/license.txt'
   }

I have to exclude all of them because there apparently is a duplicate file in all of them.

I'd like to know why this problem occurs. Is it a bug of the android plugin or the gradle itself? Can excluding the above files cause any problems? Am I just excluding the above mentioned jars or is there anything else in those META-INF files? I don't want to exclude anything my project needs

Answer 1

First this is not a bug of gradle . It occurs in MergeJavaResourcesTransform task:

As we know ,APK is just a zip file, so when put META-INFO/xxx into zip file, if file has been added before ,we can not put it again.

And there is no merge rules for META-INFO files , so we can only add on file which names NOTICE etc