build error

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\xingle\.gradle\caches\modules-2\files-2.1\com.fasterxml.jackson.core\jackson-annotations\2.8.0\45b426f7796b741035581a176744d91090e2e6fb\jackson-annotations-2.8.0.jar
    File2: C:\Users\xingle\.gradle\caches\modules-2\files-2.1\com.fasterxml.jackson.core\jackson-databind\2.8.0\95505afd940fedb0d674a83583ae65a9c25ec9f\jackson-databind-2.8.0.jar
    File3: C:\Users\xingle\.gradle\caches\modules-2\files-2.1\com.fasterxml.jackson.core\jackson-core\2.8.0\eeed20590bf2a6e367e6e5ce33f44d353881fa23\jackson-core-2.8.0.jar

修改方法，build.gradle添加：

android {  
    packagingOptions {  
        exclude 'META-INF/LICENSE'  
    }  
}