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Kotlin Android Retrofit 2.6.0 with coroutines error handling

Tags:

android

kotlin

retrofit

retrofit2

I am using Retrofit 2.6.0 with coroutines for my web service call. I am getting the API response properly with all response codes (success & error cases). My Issue is when I disconnect the internet(Wifi/mobile data) in between an API call, from the code that I have written, the error is not getting caught properly. The errors most of the time are ConnectException and SocketException.

I have tried to catch the error using interceptor and also in from the ViewModel where initiated my call as well. but here as well, the exception is not getting caught and handled.

//ApiService
@GET(ApiUrl.API_DASHBOARD)
    suspend fun getHomeUiDetails(@Header("Authorization") authHeader: String): Response<HomeDetailsResponse>

//ConnectionBridge
suspend fun getHomeUiDetails(authToken: String): Response<HomeDetailsResponse> {
        return ApiServiceGenerator.BASIC_CLIENT_CONTRACT.getHomeUiDetails(authToken)
    }

// ViewModel
viewModelScope.launch(Dispatchers.IO) {
   val apiResponse = ApiConnectionBridge.getHomeUiDetails(SharedPrefUtils.getAuthToken(context))
        if (apiResponse.isSuccessful) {
           // success case
        } else {
            // error case
        }
}

object ApiServiceGenerator {

    val BASIC_CLIENT_CONTRACT: ApiService = ApiClient
        .getContract(
            ApiService::class.java,
            true,
            BuildConfig.BASE_URL
        )
}

object ApiClient {

    fun <T> getContract(clazz: Class<T>, isAuth: Boolean, baseUrl: String): T {
        return getRetrofitBuilder(baseUrl, getContractBuilder(isAuth)).create(clazz)
    }

    private fun getRetrofitBuilder(baseUrl: String, builder: OkHttpClient.Builder): Retrofit {
        val gson = GsonBuilder().serializeNulls().create()

        val loggingInterceptor = HttpLoggingInterceptor()
        loggingInterceptor.level = HttpLoggingInterceptor.Level.BODY

        val okHttpClient = OkHttpClient.Builder()
            .addInterceptor { chain ->
                val original = chain.request()

                // Customize the request
                val request = original.newBuilder()
                request.header("Content-Type", "application/x-www-form-urlencoded")

                var response: Response? = null
                try {
                    response = chain.proceed(request.build())
                    response.cacheResponse()

                    // Customize or return the response

                    response!!
                } catch (e: ConnectException) {
                            Log.e("RETROFIT", "ERROR : " + e.localizedMessage)
                    chain.proceed(original)
                } catch (e: SocketException) {
                    Log.e("RETROFIT", "ERROR : " + e.localizedMessage)
                    chain.proceed(original)
                } catch (e: IOException) {
                    Log.e("RETROFIT", "ERROR : " + e.localizedMessage)
                    chain.proceed(original)
                } catch (e: Exception) {
                    Log.e("RETROFIT", "ERROR : " + e.localizedMessage)
                    chain.proceed(original)
                }
            }
            //            .cache(cache)
            .eventListener( object : EventListener() {
                override fun callFailed(call: Call, ioe: IOException) {
                    super.callFailed(call, ioe)
                }

            })
            .addInterceptor(loggingInterceptor)
            .readTimeout(60, TimeUnit.SECONDS)
            .connectTimeout(60, TimeUnit.SECONDS)
            .build()

        return Retrofit.Builder()
            .baseUrl(baseUrl)
            .client(okHttpClient)//getUnsafeOkHttpClient()
            .addConverterFactory(GsonConverterFactory.create(gson))
            .build()
    }
}

The stack trace:

2019-08-02 14:15:12.819 4157-4288/com.my.app E/AndroidRuntime: FATAL EXCEPTION: DefaultDispatcher-worker-3
Process: com.my.app, PID: 4157
java.net.ConnectException: Failed to connect to my_url
    at okhttp3.internal.connection.RealConnection.connectSocket(RealConnection.java:248)
    at okhttp3.internal.connection.RealConnection.connect(RealConnection.java:166)
    at okhttp3.internal.connection.StreamAllocation.findConnection(StreamAllocation.java:257)
    at okhttp3.internal.connection.StreamAllocation.findHealthyConnection(StreamAllocation.java:135)
    at okhttp3.internal.connection.StreamAllocation.newStream(StreamAllocation.java:114)
    at okhttp3.internal.connection.ConnectInterceptor.intercept(ConnectInterceptor.java:42)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:121)
    at okhttp3.internal.cache.CacheInterceptor.intercept(CacheInterceptor.java:93)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:121)
    at okhttp3.internal.http.BridgeInterceptor.intercept(BridgeInterceptor.java:93)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147)
    at okhttp3.internal.http.RetryAndFollowUpInterceptor.intercept(RetryAndFollowUpInterceptor.java:126)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:121)
    at okhttp3.logging.HttpLoggingInterceptor.intercept(HttpLoggingInterceptor.java:213)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:121)
    at com.my.app.network.ApiClient$getRetrofitBuilder$okHttpClient$1.intercept(ApiClient.kt:50)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:121)
    at okhttp3.RealCall.getResponseWithInterceptorChain(RealCall.java:254)
    at okhttp3.RealCall$AsyncCall.execute(RealCall.java:200)
    at okhttp3.internal.NamedRunnable.run(NamedRunnable.java:32)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
    at java.lang.Thread.run(Thread.java:764)
 Caused by: java.net.ConnectException: failed to connect to my_url (port 80) from /:: (port 0) after 60000ms: connect failed: ENETUNREACH (Network is unreachable)
    at libcore.io.IoBridge.connect(IoBridge.java:137)
    at java.net.PlainSocketImpl.socketConnect(PlainSocketImpl.java:137)
    at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:390)
    at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:230)
    at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:212)
    at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:436)
    at java.net.Socket.connect(Socket.java:621)
    at okhttp3.internal.platform.AndroidPlatform.connectSocket(AndroidPlatform.java:73)
    at okhttp3.internal.connection.RealConnection.connectSocket(RealConnection.java:246)
    at okhttp3.internal.connection.RealConnection.connect(RealConnection.java:166) 
    at okhttp3.internal.connection.StreamAllocation.findConnection(StreamAllocation.java:257) 
    at okhttp3.internal.connection.StreamAllocation.findHealthyConnection(StreamAllocation.java:135) 
    at okhttp3.internal.connection.StreamAllocation.newStream(StreamAllocation.java:114) 
    at okhttp3.internal.connection.ConnectInterceptor.intercept(ConnectInterceptor.java:42) 
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147) 
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:121) 
    at okhttp3.internal.cache.CacheInterceptor.intercept(CacheInterceptor.java:93) 
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147) 
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:121) 
    at okhttp3.internal.http.BridgeInterceptor.intercept(BridgeInterceptor.java:93) 
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147) 
    at okhttp3.internal.http.RetryAndFollowUpInterceptor.intercept(RetryAndFollowUpInterceptor.java:126) 
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147) 
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:121) 
    at okhttp3.logging.HttpLoggingInterceptor.intercept(HttpLoggingInterceptor.java:213) 
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147) 
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:121) 
    at com.my.app.network.ApiClient$getRetrofitBuilder$okHttpClient$1.intercept(ApiClient.kt:50) 
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147) 
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:121) 
    at okhttp3.RealCall.getResponseWithInterceptorChain(RealCall.java:254) 
    at okhttp3.RealCall$AsyncCall.execute(RealCall.java:200) 
    at okhttp3.internal.NamedRunnable.run(NamedRunnable.java:32) 
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167) 
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641) 
    at java.lang.Thread.run(Thread.java:764) 
 Caused by: android.system.ErrnoException: connect failed: ENETUNREACH (Network is unreachable)
    at libcore.io.Linux.connect(Native Method)
    at libcore.io.BlockGuardOs.connect(BlockGuardOs.java:118)
    at libcore.io.IoBridge.connectErrno(IoBridge.java:168)
    at libcore.io.IoBridge.connect(IoBridge.java:129)
    at java.net.PlainSocketImpl.socketConnect(PlainSocketImpl.java:137) 
    at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:390) 
    at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:230) 
    at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:212) 
    at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:436) 
    at java.net.Socket.connect(Socket.java:621) 
    at okhttp3.internal.platform.AndroidPlatform.connectSocket(AndroidPlatform.java:73) 
    at okhttp3.internal.connection.RealConnection.connectSocket(RealConnection.java:246) 
    at okhttp3.internal.connection.RealConnection.connect(RealConnection.java:166) 
    at okhttp3.internal.connection.StreamAllocation.findConnection(StreamAllocation.java:257) 
    at okhttp3.internal.connection.StreamAllocation.findHealthyConnection(StreamAllocation.java:135) 
    at okhttp3.internal.connection.StreamAllocation.newStream(StreamAllocation.java:114) 
    at okhttp3.internal.connection.ConnectInterceptor.intercept(ConnectInterceptor.java:42) 
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147) 
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:121) 
    at okhttp3.internal.cache.CacheInterceptor.intercept(CacheInterceptor.java:93) 
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147) 
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:121) 
    at okhttp3.internal.http.BridgeInterceptor.intercept(BridgeInterceptor.java:93) 
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147) 
    at okhttp3.internal.http.RetryAndFollowUpInterceptor.intercept(RetryAndFollowUpInterceptor.java:126) 
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147) 
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:121) 
    at okhttp3.logging.HttpLoggingInterceptor.intercept(HttpLoggingInterceptor.java:213) 
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147) 
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:121) 
    at com.my.app.network.ApiClient$getRetrofitBuilder$okHttpClient$1.intercept(ApiClient.kt:50) 
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147) 
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:121) 
    at okhttp3.RealCall.getResponseWithInterceptorChain(RealCall.java:254) 
    at okhttp3.RealCall$AsyncCall.execute(RealCall.java:200) 
    at okhttp3.internal.NamedRunnable.run(NamedRunnable.java:32) 
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167) 
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641) 
    at java.lang.Thread.run(Thread.java:764)
like image 608
shaheer_ Avatar asked Aug 02 '19 08:08

shaheer_

4 Answers

Well, that's what I do, just to reduce try-catch junk copypaste

Declare our API call methods like this

@GET("do/smth")
suspend fun doSomething(): SomeCustomResponse

In a separate file

suspend fun <T: Any> handleRequest(requestFunc: suspend () -> T): kotlin.Result<T> {
    return try {
        Result.success(requestFunc.invoke())
    } catch (he: HttpException) {
        Result.failure(he)
    }
}

Usage:

suspend fun doSmth(): kotlin.Result<SomeCustomResponse> {
    return handleRequest { myApi.doSomething() }
}

HTTP codes are handled by Retrofit - it just throws an HttpException if responseCode is not 2xx. So what we should do is just catch this exception.

I know, it is not a perfect solution, but let's for Jake to invent something better)

like image 92
Artur Matsehor Avatar answered Oct 13 '22 21:10

Artur Matsehor

You can just add a CoroutineExceptionHandler to handle the error for you:

In your ViewModel:

val coroutineExceptionHandler = CoroutineExceptionHandler{_, t -> {
  t.printStackTrace()
  showErrorOrSomething()
}}

viewModelScope.launch(Dispatchers.IO + coroutineExceptionHandler) {
   val apiResponse = ApiConnectionBridge.getHomeUiDetails(SharedPrefUtils.getAuthToken(context))
        if (apiResponse.isSuccessful) {
           // success case
        } else {
            // error case
        }
}
like image 33
coroutineDispatcher Avatar answered Oct 13 '22 21:10

coroutineDispatcher

An addition to Arthur Matsegor's answer:

In my case API returns to me an error message for bad requests. For this scenario, i need to catch error message on Catch function. I know, writing try/catch to Catch function looks like ugly but it's worked.

private suspend fun <T : Any> handleRequest(requestFunc: suspend () -> T): Result<T> {
    return try {
        Result.success(requestFunc.invoke())
    } catch (httpException: HttpException) {
        val errorMessage = getErrorMessageFromGenericResponse(httpException)
        if (errorMessage.isNullOrBlank()) {
            Result.failure(httpException)
        } else {
            Result.failure(Throwable(errorMessage))
        }
    }
}

private fun getErrorMessageFromGenericResponse(httpException: HttpException): String? {
    var errorMessage: String? = null
    try {
        val body = httpException.response()?.errorBody()
        val adapter = Gson().getAdapter(GenericResponse::class.java)
        val errorParser = adapter.fromJson(body?.string())
        errorMessage = errorParser.errorMessage?.get(0)
    } catch (e: IOException) {
        e.printStackTrace()
    } finally {
        return errorMessage
    }
}
like image 2
Mete Avatar answered Oct 13 '22 19:10

Mete

you could do the following in your ViewModel to gracefully handle exceptions:

viewModelScope.launch {
   kotlin.runCatching {
      withContext(Dispatchers.IO){
          ApiConnectionBridge.getHomeUiDetails(SharedPrefUtils.getAuthToken(context))
      }

  }.onSuccess { 
       // do something with success response
  }.onFailure{
      // do something on failure response
  }

}
like image 1
chikwapuro Avatar answered Oct 13 '22 21:10

chikwapuro
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