retrofit2.协程用法下 获取errorbody

参考链接：https://stackoverflow.com/questions/55780644/how-to-handle-error-response-with-retrofit-coroutines

需求：

网络请求。后台返回500。但是需要显示body的json

{"code":201,"data":null,"message":"劵码非法:【yyy】","success":false}

retrofit2在非200的情况下都是会抛出异常。

只需要catch 

retrofit2.HttpException

就可以获取到response 进而读取errorbody

    suspend fun  safeApiCall(call: suspend () -> Result, errorMessage: String): Result {
        return try {
            call()
        }catch (httpex :HttpException){
            //默认的错误提示语
            var errorMessage = errorMessage
            //获取response
            var response= httpex.response()
            //获取错误body的内容
            val json = response?.errorBody()?.string()

            //尝试转换成统一的json，try catch 是防止此异常并非服务器返回
            try {
                val baseJson = Gson().fromJson(json,BaseJson::class.java)
                errorMessage = baseJson.message?:errorMessage
            }catch (e:java.lang.Exception){
                //json 转换异常就不处理了
                e.printStackTrace()
            }
            Result.Error(IOException(errorMessage))
        }
        catch (e: Exception) {
            e.printStackTrace()
            // An exception was thrown when calling the API so we're converting this to an IOException
            Result.Error(IOException(errorMessage, e))
        }
    }