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android – Retrofit 2 example tutorial but GsonConverterFactory display error "Cannot resolve symbol"

Posted by: admin April 23, 2020 Leave a comment


I’m trying to follow Retrofit’s 2 tutorial, but on this part of the code there is a GsonConverterFactory that displays error Cannot resolve symbol:

public class ServiceGenerator {

    public static final String API_BASE_URL = "http://your.api-base.url";

    private static OkHttpClient httpClient = new OkHttpClient();
    private static Retrofit.Builder builder =
            new Retrofit.Builder()
                    //THIS IS THE LINE WITH ERROR!!!!!!!!!!!!

    public static <S> S createService(Class<S> serviceClass) {
        Retrofit retrofit = builder.client(httpClient).build();
        return retrofit.create(serviceClass);

Previously I added in my gradle.build, I’m not sure if I should add GSON since they say Retrofit 1.9 has it but nothing is mentioned about Retrofit 2:

dependencies {  
    // Retrofit & OkHttp
    compile 'com.squareup.retrofit:retrofit:2.0.0-beta2'
How to&Answers:


retrofit 2 is now stable. Use

compile 'com.squareup.retrofit2:retrofit:2.3.0'
compile 'com.squareup.retrofit2:converter-gson:2.3.0'

in your build.gradle dependency section

old answer

with Retrofit 2.0 you have to declare in your build.gradle the convert factory you want to use. Add

compile 'com.squareup.retrofit:converter-gson:2.0.0-beta2'

to your gradle and sync it again


From another article on that site

Retrofit 2 doesn’t ship with Gson by default. Before, you didn’t need to worry about any integrated converter and you could use Gson out of the box. This library change affects your app and you need to import a converter as a sibling package as well. We’ll touch the converter later within this post and show you how to config the Gson or any other response converter for your app.

Thus, add this to your build.gradle

dependencies {  
    compile 'com.squareup.retrofit:converter-gson:2.0.0-beta2'


The reason to such behavior in my case was typo in build.gradle dependency.
After beta4 release I’ve updated from:

compile 'com.squareup.retrofit:converter-gson:2.0.0-beta2'


 compile 'com.squareup.retrofit:converter-gson:2.0.0-beta4'

and the right dependency was

compile 'com.squareup.retrofit2:converter-gson:2.0.0-beta4'

Also worth notice, that beta4 – retrofit won’t work with beta2 – gson!


As Updated Retrofit Library with New Version


compile 'com.squareup.retrofit2:retrofit:2.0.2'

You must have to include dependency of:

compile 'com.squareup.retrofit2:converter-gson:2.0.2'


New version is now available

compile 'com.squareup.retrofit2:retrofit:2.1.0'
compile 'com.squareup.retrofit2:converter-gson:2.1.0'


I have used

RestService restService=new Retrofit.Builder()
                    .client(new OkHttpClient.Builder().readTimeout(60, TimeUnit.SECONDS).connectTimeout(60, TimeUnit.SECONDS).build())

    compile 'com.squareup.retrofit2:retrofit:2.1.0'
    compile 'com.squareup.retrofit2:converter-gson:2.1.0'
    // RxJava adapter for retrofit
    compile 'com.squareup.retrofit2:adapter-rxjava:2.1.0'
    // RxJava libraries
    compile 'io.reactivex:rxjava:1.0.10'
    compile 'io.reactivex:rxandroid:1.1.0'

use retrofit and gson of the same version code


compile 'com.google.code.gson:gson:2.6.2'
compile 'com.squareup.retrofit2:retrofit:2.0.2'
compile 'com.squareup.retrofit2:converter-gson:2.0.2'

use this