Retrofit 2.4.0 with proguard

Question

When I add Retrofit 2.4.0 library to android project >

implementation 'com.squareup.retrofit2:retrofit:2.4.0'

and set minifyEnabled {true}

 buildTypes {
        release {
            minifyEnabled true
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }

and then add these rules to proguard-rules.pro

-keep class com.squareup.** { *; }
-keep interface com.squareup.** { *; }
-keep class retrofit2.** { *; }
-keep interface retrofit2.** { *;}
-keep interface com.squareup.** { *; }


-keepclasseswithmembers class * {
    @retrofit2.http.* <methods>;
}


-dontwarn rx.**
-dontwarn retrofit2.**
-dontwarn okhttp3.**
-dontwarn okio.**

Finally built and generated signed apk successfully but the issue is when run the ( release apk) > Retrofit requests not send and return { null } .. Whats the solution Please!

Answer 1

maybe because of other library work with retrofit like your downloader or parser.

important notice :

add rule to keep your model classes and subjects that work with parser like :

-keep class com.address_package.** { *; }

if you use okhttp or Okhttp3 with retrofit added below rules

note :and check your parser proguard rules too

LIBRARY: OkHttp

-keep class com.squareup.okhttp.** { *; }
-keep interface com.squareup.okhttp.** { *; }

-dontwarn com.squareup.okhttp.**
-dontwarn okio.**

okhttp3

-keepattributes Signature
-keepattributes *Annotation*
-keep class okhttp3.** { *; }
-keep interface okhttp3.** { *; }

-dontwarn okhttp3.**

Answer 2

Your Proguard rules work for Retrofit, but they're also obfuscating the model classes that you use to serialize/deserialize your data. Their names are important as Retrofit/Gson matches them to do serializing/deserializing. Proguard turns them into gibberish like a and b so Retrofit/Gson cannot make sense of them.

Depending on your package setup, you need to add the following like amin mahmodi mentioned.

-keep class your.package.name.models.** { *; }

Answer 3

This answer may be quite late, but it could help someone else.

Instead of keeping an entire classes with:

-keep class your.package.name.models.** { *; }

You can use:

-keepclassmembers class * {
   @com.google.gson.annotations.SerializedName <fields>;
}

This would allow you to place your models anywhere you'd like and not include them in the ProGuard file as a separate rule each time you change their project location.