Explain what is the error "Duplicate files copied in APK META-INF/LICENSE" and is it correct to solve this?

Question

Android

Kind
connected the library

compile group: 'com.fasterxml.jackson.core', name: 'jackson-databind', version: '2.9.1'

, the application began to pour during assembly

Error:Execution failed for task ':app:transformResourcesWithMergeJavaResForDebug'.
> com.android.build.api.transform.TransformException: com.android.builder.packaging.DuplicateFileException: Duplicate files copied in APK META-INF/LICENSE
File1: C:\Users\www\.gradle\caches\modules-2 \files-2.1\com.fasterxml.jackson.core\jackson-databind\2.9.1\716da1830a2043f18882fc036ec26eb32cbe5aff\jackson-databind-2.9.1.jar
File2: C:\Users\www\.gradle\caches\modules-2\ files-2.1\com.fasterxml.jackson.core\jackson-annotations\2.9.0\7c10d545325e3a6e72e06381afe469fd40eb701\jackson-annotations-2.9.0.jar
File3: C:\Users\www\.gradle\caches\modules-2\files -2.1\com.fasterxml.jackson.core\jackson-core\2.9.1\60077fe98b11e4e7cf8af9b20609326a166d6ac4\jackson-core-2.9.1.jar

I found a quick solution on the internet, add it to the gredl

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

What duplicate files - what is the problem?

Answer 1

It's all right, these files are excluded using gredl.
The usual information about the license, it is almost always there, and it is a good idea to remove it when assembling.