Retrofit2 DuplicateFileException

Question

Hi im new to retrofit and I got this 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/maven/com.squareup.retrofit2/retrofit/pom.properties
    File1: C:\Users\LouDoms\Documents\PICZON\LoOck2\app\libs\retrofit-2.0.0-beta3.jar
    File2: C:\Users\LouDoms\.gradle\caches\modules-2\files-2.1\com.squareup.retrofit2\retrofit\2.0.0-beta3\97675641051febfee098903cc0eff62f2826e34e\retrofit-2.0.0-beta3.jar

I tried to include the packaging options but they didn't work. Someone help me please as I don't know what to do or what to remove.

My gradle looks like this:

apply plugin: 'com.android.application'

android {
compileSdkVersion 23
buildToolsVersion "23.0.0"

defaultConfig {
    applicationId "com.example.loudoms.loock"
    minSdkVersion 15
    targetSdkVersion 23
    versionCode 1
    versionName "1.0"
}
buildTypes {
    release {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
    }
}

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

dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
compile 'com.android.support:support-v4:23.1.1'
compile 'com.android.support:appcompat-v7:23.1.1'
compile 'com.android.support:recyclerview-v7:23.1.1'
compile 'com.android.support:cardview-v7:23.1.1'
compile 'com.android.support:design:23.1.1'
compile 'com.squareup.retrofit2:retrofit:2.0.0-beta3'
compile 'com.squareup.retrofit2:converter-gson:2.0.0-beta3'
compile 'com.jakewharton:butterknife:7.0.1'
}

Answer 1

This question is because ModuleA and ModuleB has same jar(also this jar has META-INF direct)， method is：create a new Module(select Library)，then take the jar join to this Module's "libs" direct，then let ModuleA and ModuleB dependent this Module Library. In this way,no DuplicateFileException.