Retrofit is the class through which your API interfaces are turned into callable objects. By default, Retrofit will give you sane defaults for your platform but it allows for customization.
CONVERTERS
By default, Retrofit can only deserialize HTTP bodies into OkHttp’s ResponseBody type and it can only accept its RequestBody type for @Body.
Converters can be added to support other types. Six sibling modules adapt popular serialization libraries for your convenience.
- Gson:
com.squareup.retrofit2:converter-gson - Jackson:
com.squareup.retrofit2:converter-jackson - Moshi:
com.squareup.retrofit2:converter-moshi - Protobuf:
com.squareup.retrofit2:converter-protobuf - Wire:
com.squareup.retrofit2:converter-wire - Simple XML:
com.squareup.retrofit2:converter-simplexml - JAXB:
com.squareup.retrofit2:converter-jaxb - Scalars (primitives, boxed, and String):
com.squareup.retrofit2:converter-scalars
Here’s an example of using the GsonConverterFactory class to generate an implementation of the GitHubService interface which uses Gson for its deserialization.
Retrofit retrofit = new Retrofit.Builder()
.baseUrl("https://api.github.com/")
.addConverterFactory(GsonConverterFactory.create())
.build();
GitHubService service = retrofit.create(GitHubService.class);CUSTOM CONVERTERS
If you need to communicate with an API that uses a content-format that Retrofit does not support out of the box (e.g. YAML, txt, custom format) or you wish to use a different library to implement an existing format, you can easily create your own converter. Create a class that extends the Converter.Factory class and pass in an instance when building your adapter.