Coroutine cannot catch exceptions

When the network requests, json has an exception, kotlin coroutine cannot catch the exception, and the application crashes.

retrofit = Retrofit.Builder()
            .baseUrl(baseUrl)
            .addConverterFactory(GsonConverterFactory.create())
            .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
            .client(okHttpClient)
            .build()

NetworkInterceptor

override fun intercept(chain: Interceptor.Chain): Response {

        val request = newRequest(chain)
        val response = chain.proceed(request)
        return adapterData(response)   
 }

  private fun adapterData(response: Response): Response{
        response.body()?.let {body ->
            var json = body.string()
            //org.json.JSONException: End of input at character 0 of
            val job = JSONObject(json)
            ...
            val newBody = ResponseBody.create(body.contentType(), json)
            // new response
            return response.newBuilder().body(newBody).build()
        }
        return response
    }

fun CoroutineScope.launchTryCatch(block: suspend CoroutineScope.() -> Unit,
                                  onError: ((t: Throwable) -> Unit)?){
    launch {
        try {
            block()
        }catch (t: Throwable){
            onError?.invoke(t)
        }
    }
}

viewModelScope.launchTryCatch({
            Repository.device().groupName(group.groupId, content)
            ...
        }, ::handleException)

Coroutine uses try/catch and still can’t catch the exception. Is there anything wrong with the usage?

[swankjesse]

This isn’t due to Retrofit coroutines; rather it’s in the contract for OkHttp Interceptors. They are only allowed to throw IOExceptions; any other exception is a crash and is delivered to the uncaught exception handler.

If you need an exception then use an IOException subclass, or wrap your exception in an IOException.

[mboukadir]

Ok, thanks for your reply.