How to make RxErrorHandlingCallAdapterFactory?

Question

I found this.

But in new ver compile \'com.squareup.retrofit2:adapter-rxjava:2.2.0\' at CallAdapter it has two params CallAdapter

Answer 1

Updated anwer of Fred to kotlin style and

rxjava1:

com.squareup.retrofit2:adapter-rxjava:2.5.0 with io.reactivex:rxjava:1.3.8

RxErrorHandlingCallAdapterFactory.kt

import retrofit2.Call
import retrofit2.CallAdapter
import retrofit2.HttpException
import retrofit2.Retrofit
import retrofit2.adapter.rxjava.RxJavaCallAdapterFactory
import rx.Observable
import java.io.IOException
import java.lang.reflect.Type

/**
 * Created by Nikolay Unuchek on 28.11.2016.
 */

internal class RxErrorHandlingCallAdapterFactory private constructor() : CallAdapter.Factory() {
    private val original: RxJavaCallAdapterFactory = RxJavaCallAdapterFactory.create()

    override fun get(returnType: Type, annotations: Array, retrofit: Retrofit): CallAdapter<*, *>? {
        return RxCallAdapterWrapper(retrofit, original.get(returnType, annotations, retrofit) ?: return null)
    }

    private class RxCallAdapterWrapper(
        private val retrofit: Retrofit,
        private val wrapped: CallAdapter
    ) : CallAdapter {

        override fun responseType(): Type {
            return wrapped.responseType()
        }

        override fun adapt(call: Call): Any {
            val result = wrapped.adapt(call)
            if (result is Observable<*>) {
                return result.onErrorResumeNext { throwable -> Observable.error(asRetrofitException(throwable as Throwable)) }
            }

            return result
        }

        private fun asRetrofitException(throwable: Throwable): RetrofitException {
            // We had non-200 http error
            if (throwable is HttpException) {
                val response = throwable.response()
                return RetrofitException.httpError(response.raw().request.url.toString(), response, throwable)
            }
            // A network error happened
            return if (throwable is IOException) {
                RetrofitException.networkError(throwable)
            } else RetrofitException.unexpectedError(throwable)

            // We don't know what happened. We need to simply convert to an unknown error

        }
    }

    companion object {

        fun create(): CallAdapter.Factory {
            return RxErrorHandlingCallAdapterFactory()
        }
    }
}

RetrofitException.kt

import retrofit2.HttpException
import retrofit2.Response
import java.io.IOException
class RetrofitException
private constructor(
    message: String?,
    /**
     * The request URL which produced the error.
     */
    val url: String?,
    /**
     * Response object containing status code, headers, body, etc.
     */
    val response: Response<*>?,
    /**
     * The event kind which triggered this error.
     */
    val kind: Kind,
    exception: Throwable
) : RuntimeException(message, exception) {

    override fun toString(): String {
        return super.toString() + " : " + kind + " : " + url + " : " + response?.errorBody()?.string()
    }

    /**
     * Identifies the event kind which triggered a [RetrofitException].
     */
    enum class Kind {
        /**
         * An [IOException] occurred while communicating to the server.
         */
        NETWORK,
        /**
         * A non-200 HTTP status code was received from the server.
         */
        HTTP,
        /**
         * An internal error occurred while attempting to execute a request. It is best practice to
         * re-throw this exception so your application crashes.
         */
        UNEXPECTED
    }

    companion object {
        fun httpError(url: String, response: Response<*>, httpException: HttpException): RetrofitException {
            val message = response.code().toString() + " " + response.message()
            return RetrofitException(message, url, response, Kind.HTTP, httpException)
        }

        fun networkError(exception: IOException): RetrofitException {
            return RetrofitException(exception.message, null, null, Kind.NETWORK, exception)
        }

        fun unexpectedError(exception: Throwable): RetrofitException {
            return RetrofitException(exception.message, null, null, Kind.UNEXPECTED, exception)
        }

        fun asRetrofitException(throwable: Throwable): RetrofitException {
            if (throwable is RetrofitException) {
                return throwable
            }
            // We had non-200 http error
            if (throwable is HttpException) {
                val response = throwable.response()
                return httpError(response.raw().request().url().toString(), response, throwable)
            }
            // A network error happened
            return if (throwable is IOException) {
                networkError(throwable)
            } else unexpectedError(throwable)
            // We don't know what happened. We need to simply convert to an unknown error
        }
    }
}

rxjava2:

com.squareup.retrofit2:adapter-rxjava2:2.6.0 with io.reactivex.rxjava2:rxjava:2.2.9

RxErrorHandlingCallAdapterFactory.kt

import by.gramophone.api.errorhandling.RetrofitException.Companion.asRetrofitException
import io.reactivex.Completable
import io.reactivex.Observable
import io.reactivex.Single
import io.reactivex.functions.Function
import retrofit2.Call
import retrofit2.CallAdapter
import retrofit2.Retrofit
import retrofit2.adapter.rxjava2.RxJava2CallAdapterFactory
import java.lang.reflect.Type



/**
 * Created by Nikolay Unuchek on 28.11.2016.
 */

internal class RxErrorHandlingCallAdapterFactory private constructor() : CallAdapter.Factory() {
    private val original = RxJava2CallAdapterFactory.create()

    override fun get(returnType: Type, annotations: Array, retrofit: Retrofit): CallAdapter<*, *>? {
        return RxCallAdapterWrapper(original.get(returnType, annotations, retrofit) ?: return null)
    }

    private class RxCallAdapterWrapper(private val wrapped: CallAdapter) : CallAdapter {

        override fun responseType(): Type {
            return wrapped.responseType()
        }

        override fun adapt(call: Call): Any {
            return when (val result = wrapped.adapt(call)) {
                is Single<*> -> result.onErrorResumeNext(Function { throwable -> Single.error(asRetrofitException(throwable)) })
                is Observable<*> -> result.onErrorResumeNext(Function { throwable -> Observable.error(asRetrofitException(throwable)) })
                is Completable -> result.onErrorResumeNext (Function{ throwable -> Completable.error(asRetrofitException(throwable)) } )
                else -> result
            }

        }
    }

    companion object {
        fun create(): CallAdapter.Factory {
            return RxErrorHandlingCallAdapterFactory()
        }
    }
}

RetrofitException.kt

import retrofit2.HttpException
import retrofit2.Response
import java.io.IOException
class RetrofitException
private constructor(
    message: String?,
    /**
     * The request URL which produced the error.
     */
    val url: String?,
    /**
     * Response object containing status code, headers, body, etc.
     */
    val response: Response<*>?,
    /**
     * The event kind which triggered this error.
     */
    val kind: Kind,
    exception: Throwable
) : RuntimeException(message, exception) {

    override fun toString(): String {
        return super.toString() + " : " + kind + " : " + url + " : " + response?.errorBody()?.string()
    }

    /**
     * Identifies the event kind which triggered a [RetrofitException].
     */
    enum class Kind {
        /**
         * An [IOException] occurred while communicating to the server.
         */
        NETWORK,
        /**
         * A non-200 HTTP status code was received from the server.
         */
        HTTP,
        /**
         * An internal error occurred while attempting to execute a request. It is best practice to
         * re-throw this exception so your application crashes.
         */
        UNEXPECTED
    }

    companion object {
        fun httpError(url: String, response: Response<*>, httpException: HttpException): RetrofitException {
            val message = response.code().toString() + " " + response.message()
            return RetrofitException(message, url, response, Kind.HTTP, httpException)
        }

        fun networkError(exception: IOException): RetrofitException {
            return RetrofitException(exception.message, null, null, Kind.NETWORK, exception)
        }

        fun unexpectedError(exception: Throwable): RetrofitException {
            return RetrofitException(exception.message, null, null, Kind.UNEXPECTED, exception)
        }

        fun asRetrofitException(throwable: Throwable): RetrofitException {
            if (throwable is RetrofitException) {
                return throwable
            }
            // We had non-200 http error
            if (throwable is HttpException) {
                val response = throwable.response()
                return httpError(response.raw().request().url().toString(), response, throwable)
            }
            // A network error happened
            return if (throwable is IOException) {
                networkError(throwable)
            } else unexpectedError(throwable)
            // We don't know what happened. We need to simply convert to an unknown error
        }
    }
}