CODEWITHSUNDEEP
androidandroid-recyclerviewretrofit
Naveen
Naveen

Reputation: 551

Call return type must be parameterized as Call<Foo> or Call<? extends Foo> Exception while calling retrofit API

Below are the Dependencies which I have used

implementation 'com.squareup.retrofit2:retrofit:2.0.2'
implementation 'com.squareup.retrofit2:converter-gson:2.0.2'

Below is the code which I am calling retrofit API

RequestBody jsonBody = RequestBody.create(okhttp3.MediaType.parse("application/json; charset=utf-8"),(jsonInput));

            RetrofitAPI cashMemoService = RetrofitAPICLient.getClient().create(RetrofitAPI.class);
            Call<List<CashMemoDetails>> call = cashMemoService.getCashMemoPendingListObj(jsonBody);

This is RetrofitAPICLient

public static Retrofit getClient(){
        if(retrofit == null){
            retrofit = new Retrofit.Builder()
                    .baseUrl(newBseURL)
                    .client(okHttpClient)
                    .addConverterFactory(GsonConverterFactory.create())
                    .build();
        }

        return retrofit;
    }

Below is the Interface

@POST("GetCashMemoPunchingList")
    Call<List<CashMemoDetails>> getCashMemoPendingListObj(@Body RequestBody userData);

Below is the exception which I am getting

 2020-10-20 10:59:47.320 27155-27155/ W/com.hpcl.gsa2: Accessing hidden method Ldalvik/system/CloseGuard;->warnIfOpen()V (greylist,core-platform-api, reflection, allowed)
    2020-10-20 10:59:47.335 27155-27155/ W/System.err: java.lang.IllegalArgumentException: Unable to create call adapter for interface g.g
   55-27155/ W/System.err:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:950)
    2020-10-20 10:59:47.336 27155-27155/ W/System.err: Caused by: java.lang.IllegalArgumentException: Call return type must be parameterized as Call<Foo> or Call<? extends Foo>
    2020-10-20 10:59:47.336 27155-27155/ W/System.err:  ... 22 more

Please help me on this.Thanks in advance

Upvotes: 17

Views: 6729

Answers (7)

Gaurav Singla
Gaurav Singla

Reputation: 1451

This is happening because R8 is running in fullmode. For now you can disable it by setting below flag in gradle.properties:

android.enableR8.fullMode=false

Upvotes: -2

Sepideh
Sepideh

Reputation: 61

I had this error too. Everything worked fine except signed APK's with enabled minify.I have fixed it by adding some rules to the proguard-rules.pro file. In general, for retrofit, you need to add the following rules to proguard-rules.pro:

-keepattributes Signature, InnerClasses, EnclosingMethod
-keepattributes RuntimeVisibleAnnotations, RuntimeVisibleParameterAnnotations
-keepattributes AnnotationDefault
-keepclassmembers,allowshrinking,allowobfuscation interface * {
    @retrofit2.http.* <methods>;
}
-dontwarn org.codehaus.mojo.animal_sniffer.IgnoreJRERequirement
-dontwarn javax.annotation.**
-dontwarn kotlin.Unit
-dontwarn retrofit2.KotlinExtensions
-dontwarn retrofit2.KotlinExtensions$*
-if interface * { @retrofit2.http.* <methods>; }
-keep,allowobfuscation interface <1>
-if interface * { @retrofit2.http.* <methods>; }
-keep,allowobfuscation interface * extends <1>
-keep,allowobfuscation,allowshrinking class kotlin.coroutines.Continuation
-if interface * { @retrofit2.http.* public *** *(...); }
-keep,allowoptimization,allowshrinking,allowobfuscation class <3>
-keep,allowobfuscation,allowshrinking class retrofit2.Response

Upvotes: 4

Kuki
Kuki

Reputation: 59

I have encountered the same error after renaming the package in my project. everything worked fine except signed APK's with enabled minify. I have fixed it by adding this to my proguard-rules.pro:

-keep class retrofit2.** { *; }
-keepattributes *Annotation*
-keep class com.squareup.okhttp.** { *; }
-keep interface com.squareup.okhttp.** { *; }
-keep class okhttp3.** { *; }
-keep interface okhttp3.** { *; }
-keep class com.yourproject.app.** { *; }

I suppose that the problem was in the last line. minifier might have been removing my classes because of package name mismatch, which is now prevented.

Upvotes: -1

Niroshan
Niroshan

Reputation: 1282

You need not downgrade your Gradle version solely for this purpose. When you update to Gradle 8 (or a version higher than 8), R8 will automatically be enabled in full mode. If you wish to revert to compact mode, simply add the following line to your gradle.properties file:

android.enableR8.fullMode=false

Happy coding!

Upvotes: 9

avalancha
avalancha

Reputation: 1764

This question is quite old but the problem seems to reappear from time to time. I had this error as well using Gradle 8.2.1 and com.android.tools.build:gradle 8.0.2 and a downgrade to com.android.tools.build:gradle 7.4.2 fixed it! But a downgrade is not really a solution, so I investigated a bit further

I was able to fix it by adding some of the Proguard rules from here (nameley Retrofit and Okhttp rules)

-keep class retrofit2.** { *; }
-keepattributes *Annotation*
-keep class com.squareup.okhttp.** { *; }
-keep interface com.squareup.okhttp.** { *; }
-keep class okhttp3.** { *; }
-keep interface okhttp3.** { *; }

You should also make sure that your retrofit and Okhttp versions are up-to-date and that you follow the proguard / R8 config hints laid out in the Readme

Upvotes: 29

Yuliia Ashomok
Yuliia Ashomok

Reputation: 8598

I had the same error on Release mode, no errors on Debug mode. Downgrade Gradle from 8.0.0 to 7.4.0 solved my problem.

Upvotes: 4

Hamza Israr
Hamza Israr

Reputation: 441

Dependencies

implementation "com.squareup.okhttp3:okhttp:4.9.0"
implementation 'com.squareup.okhttp3:logging-interceptor:4.7.2'

Calling Retrofit API

Get response in ResponseBody and then parse it to List of Object.

RetrofitAPI cashMemoService = RetrofitAPICLient.getClient().create(RetrofitAPI.class);
Call<ResponseBody> call = cashMemoService.getCashMemoPendingListObj(jsonBody);

Interface

@POST("GetCashMemoPunchingList")
Call<ResponseBody> getCashMemoPendingListObj(@Body RequestBody userData);

Upvotes: 3

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