Retrofit 2.6.0: Coroutines personnalisées CallAdapterFactory
Je dois faire une gestion des erreurs personnalisée dans mon API et je voulais utiliser des coroutines avec la nouvelle version de Retrofit. Comme nous n'avons plus besoin d'utiliser Deferred, notre propre Jake Wharton l'a écrit sur reddit il y a un mois
Mais j'ai des problèmes pour créer correctement le CallAdapterFactory.
Pour être précis, je ne comprends pas: "Délègue à l'usine intégrée puis encapsule la valeur dans une classe scellée"
Y a-t-il quelqu'un qui utilise déjà cette configuration qui peut vous aider?
Voici le code actuel
sealed class Results<out T: Any> {
class Success<out T: Any>(val response: T): Results<T>()
class Failure(val message: String, val serverError: ServerError?): Results<Nothing>()
object NetworkError: Results<Nothing>()
}
class ResultsCallAdapterFactory private constructor() : CallAdapter.Factory() {
companion object {
@JvmStatic
fun create() = ResultsCallAdapterFactory()
}
override fun get(returnType: Type, annotations: Array<Annotation>, retrofit: Retrofit): CallAdapter<*, *>? {
return try {
val enclosedType = returnType as ParameterizedType
val responseType = getParameterUpperBound(0, enclosedType)
val rawResultType = getRawType(responseType)
val delegate: CallAdapter<Any,Any> = retrofit.nextCallAdapter(this,returnType,annotations) as CallAdapter<Any,Any>
if(rawResultType != Results::class.Java)
null
else {
object: CallAdapter<Any,Any>{
override fun adapt(call: Call<Any>): Any {
val response = delegate.adapt(call)
//What should happen here?
return response
}
override fun responseType(): Type {
return delegate.responseType()
}
}
}
} catch (e: ClassCastException) {
null
}
}
}
Voici un exemple de travail. Un exemple GitHub est également disponible .
// build.gradle
...
dependencies {
implementation 'com.squareup.retrofit2:retrofit:2.6.1'
implementation 'com.squareup.retrofit2:converter-gson:2.6.1'
implementation 'com.google.code.gson:gson:2.8.5'
}
// test.kt
...
sealed class Result<out T> {
data class Success<T>(val data: T?) : Result<T>()
data class Failure(val statusCode: Int?) : Result<Nothing>()
object NetworkError : Result<Nothing>()
}
data class Bar(
@SerializedName("foo")
val foo: String
)
interface Service {
@GET("bar")
suspend fun getBar(): Result<Bar>
@GET("bars")
suspend fun getBars(): Result<List<Bar>>
}
abstract class CallDelegate<TIn, TOut>(
protected val proxy: Call<TIn>
) : Call<TOut> {
override fun execute(): Response<TOut> = throw NotImplementedError()
override final fun enqueue(callback: Callback<TOut>) = enqueueImpl(callback)
override final fun clone(): Call<TOut> = cloneImpl()
override fun cancel() = proxy.cancel()
override fun request(): Request = proxy.request()
override fun isExecuted() = proxy.isExecuted
override fun isCanceled() = proxy.isCanceled
abstract fun enqueueImpl(callback: Callback<TOut>)
abstract fun cloneImpl(): Call<TOut>
}
class ResultCall<T>(proxy: Call<T>) : CallDelegate<T, Result<T>>(proxy) {
override fun enqueueImpl(callback: Callback<Result<T>>) = proxy.enqueue(object: Callback<T> {
override fun onResponse(call: Call<T>, response: Response<T>) {
val code = response.code()
val result = if (code in 200 until 300) {
val body = response.body()
Result.Success(body)
} else {
Result.Failure(code)
}
callback.onResponse(this@ResultCall, Response.success(result))
}
override fun onFailure(call: Call<T>, t: Throwable) {
val result = if (t is IOException) {
Result.NetworkError
} else {
Result.Failure(null)
}
callback.onResponse(this@ResultCall, Response.success(result))
}
})
override fun cloneImpl() = ResultCall(proxy.clone())
}
class ResultAdapter(
private val type: Type
): CallAdapter<Type, Call<Result<Type>>> {
override fun responseType() = type
override fun adapt(call: Call<Type>): Call<Result<Type>> = ResultCall(call)
}
class MyCallAdapterFactory : CallAdapter.Factory() {
override fun get(
returnType: Type,
annotations: Array<Annotation>,
retrofit: Retrofit
) = when (getRawType(returnType)) {
Call::class.Java -> {
val callType = getParameterUpperBound(0, returnType as ParameterizedType)
when (getRawType(callType)) {
Result::class.Java -> {
val resultType = getParameterUpperBound(0, callType as ParameterizedType)
ResultAdapter(resultType)
}
else -> null
}
}
else -> null
}
}
/**
* A Mock interceptor that returns a test data
*/
class MockInterceptor : Interceptor {
override fun intercept(chain: Interceptor.Chain): okhttp3.Response {
val response = when (chain.request().url().encodedPath()) {
"/bar" -> """{"foo":"baz"}"""
"/bars" -> """[{"foo":"baz1"},{"foo":"baz2"}]"""
else -> throw Error("unknown request")
}
val mediaType = MediaType.parse("application/json")
val responseBody = ResponseBody.create(mediaType, response)
return okhttp3.Response.Builder()
.protocol(Protocol.HTTP_1_0)
.request(chain.request())
.code(200)
.message("")
.body(responseBody)
.build()
}
}
suspend fun test() {
val mockInterceptor = MockInterceptor()
val mockClient = OkHttpClient.Builder()
.addInterceptor(mockInterceptor)
.build()
val retrofit = Retrofit.Builder()
.baseUrl("https://mock.com/")
.client(mockClient)
.addCallAdapterFactory(MyCallAdapterFactory())
.addConverterFactory(GsonConverterFactory.create())
.build()
val service = retrofit.create(Service::class.Java)
val bar = service.getBar()
val bars = service.getBars()
...
}
...