使用Retrofit + Coroutine时如何获取服务器返回的错误体

Question

当使用 Coroutine 和 Retrofit 来调用网络 api 时，如果服务器 returns 出现错误（响应代码！= 200），我们将得到一个异常。我的问题是如何 find/read 服务器通过 Exception 发送的错误正文（在 Json 中）？

try{
     apiService.login()
}catch(exception:Exception){
     //How to read error body from exception
     //Error body example: {"ok":false,"error":"Incorrect username or password."}
}

Answer 1

您只需要这样做：

(exception as? HttpException).response()?.errorBody()?.string()

这将return Json 格式的错误正文。

Answer 2

要处理协同程序和改造的错误，您必须创建一个密封的 class，按照以下步骤...

1：状态句柄Class

sealed class NetworkState {
  data class Success(val data : CharactersResponseModel) : NetworkState()
  object InvalidData : NetworkState()
  data class Error(val error : String) : NetworkState()
  data class NetworkException(val error : String) : NetworkState()
  sealed class HttpErrors : NetworkState() {
    data class ResourceForbidden(val exception: String) : HttpErrors()
    data class ResourceNotFound(val exception: String) : HttpErrors()
    data class InternalServerError(val exception: String) : HttpErrors()
    data class BadGateWay(val exception: String) : HttpErrors()
    data class ResourceRemoved(val exception: String) : HttpErrors()
    data class RemovedResourceFound(val exception: String) : HttpErrors()
  }
}

处理错误或成功API调用

 private suspend fun fetchCharacters() : NetworkState {
 return try {
   val response = apiService.getCharacters()
   if (response.isSuccessful) {
     if (response != null) {
       NetworkState.Success(response.body()!!)
     } else {
       NetworkState.InvalidData
     }
   } else {
     when(response.code()) {
       403 -> NetworkState.HttpErrors.ResourceForbidden(response.message())
       404 -> NetworkState.HttpErrors.ResourceNotFound(response.message())
       500 -> NetworkState.HttpErrors.InternalServerError(response.message())
       502 -> NetworkState.HttpErrors.BadGateWay(response.message())
       301 -> NetworkState.HttpErrors.ResourceRemoved(response.message())
       302 -> NetworkState.HttpErrors.RemovedResourceFound(response.message())
       else -> NetworkState.Error(response.message())
     }
   }

 } catch (error : IOException) {
   NetworkState.NetworkException(error.message!!)
 }

}

在你的UI
中将 liveData 或 flow to Observer 设为 neworkState

使用Retrofit + Coroutine时如何获取服务器返回的错误体

How to get error body returned by server when using Retrofit + Coroutine

error-handling

android

exception

retrofit

kotlin-coroutines