Retrofit 2 not sending data when ProGuard is enabled

Question

I try to login my users using Retrofit 2. (Basically a GET to the login URL with a basic header) It works well but once I ProGuard it, the Header Authorization is not sent a

Answer 1

Add Retrofit 2 compatibility with Proguard code Obfuscator

    -dontwarn retrofit.**
    -keep class retrofit.** { *; }
    -keepattributes Signature
    -keepattributes Exceptions
    -dontwarn java.lang.invoke.*
    -keep class com.elephantmobile.ui.remote.model.** { *; }
    -dontwarn retrofit.appengine.UrlFetchClient
    -keepclasseswithmembers class * {
        @retrofit.http.* <methods>;
    }
    -keepclassmembernames interface * {
        @retrofit.http.* <methods>;
    }
    -dontwarn retrofit2.Platform$Java8

Answer 2

Another simple solution use @keep from support annotation https://developer.android.com/reference/android/support/annotation/Keep.html

@Keep
interface APIService 
{

    @GET("/user/auth")
    fun auth(@Header(Constants.AUTHORIZATION) authorization: String): Call<User>

}

Answer 3

You need to add

 @SerializedName("yourInputParameter")

in your bean(model) class for your request body

For example

 public class YourClass{
       @SerializedName("yourInputParameter") String yourInputParameter;

       ...
     }

it will work

because now retrofit unable to read your request body because proguard(minifyEnabled) is true

after adding @SerializedName in your request body it will definitely work for you

Answer 4

I finally managed to make it work. Here is the proguard configuration regarding Retrofit 2

# Retrofit
-dontwarn retrofit2.**
-dontwarn org.codehaus.mojo.**
-keep class retrofit2.** { *; }
-keepattributes Signature
-keepattributes Exceptions
-keepattributes *Annotation*

-keepattributes RuntimeVisibleAnnotations
-keepattributes RuntimeInvisibleAnnotations
-keepattributes RuntimeVisibleParameterAnnotations
-keepattributes RuntimeInvisibleParameterAnnotations

-keepattributes EnclosingMethod

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

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

Thanks @xudshen

UPDATE

The main problem: I used proguard-android-optimize So I should added:

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

I also switched back to the regular Retrofit 2 proguard config provided by square :

# Platform calls Class.forName on types which do not exist on Android to determine platform.
-dontnote retrofit2.Platform
# Platform used when running on RoboVM on iOS. Will not be used at runtime.
-dontnote retrofit2.Platform$IOS$MainThreadExecutor
# Platform used when running on Java 8 VMs. Will not be used at runtime.
-dontwarn retrofit2.Platform$Java8
# Retain generic type information for use by reflection by converters and adapters.
-keepattributes Signature
# Retain declared checked exceptions for use by a Proxy instance.
-keepattributes Exceptions

Answer 5

for me works using annotation @SerializedName

public class YourJsonClass{
   @SerializedName("name") String username;

   ...
 }

Answer 6

Adding to @Romain's answer You Need to add to proguard file

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

If you are using @Header, @Query...

Reference from here Retrofit2 proguard remove param