Kotlin Multiplatform - 使用 Ktor 处理响应 http 代码和异常
Posted
技术标签:
【中文标题】Kotlin Multiplatform - 使用 Ktor 处理响应 http 代码和异常【英文标题】:Kotlin Multiplatform - Handle response http code and exceptions with Ktor 【发布时间】:2020-12-27 22:13:24 【问题描述】:我刚开始探索 KMM,目前看来真的很不错。
基本上,我想要在一个地方全局处理所有 http 错误代码(如 401、404、500)。
但是,我不确定如何与响应交互。
我在 HttpClient 中安装了 ResponseObserver,但它只有在 http 状态为 200 时才会出现。
我也尝试使用 HttpResponseValidator,但它从不到那里。
代码如下:
class ApiImpl : Api
private val httpClient = HttpClient
install(JsonFeature)
val json = kotlinx.serialization.json.Json ignoreUnknownKeys = true
serializer = KotlinxSerializer(json)
install(ResponseObserver)
onResponse response ->
//*** We get here only if http status code is 200 ***/
println("HTTP status: $response.status.value")
HttpResponseValidator
validateResponse response: HttpResponse ->
val statusCode = response.status.value
//*** We never get here ***/
println("HTTP status: $statusCode")
when (statusCode)
in 300..399 -> throw RedirectResponseException(response)
in 400..499 -> throw ClientRequestException(response)
in 500..599 -> throw ServerResponseException(response)
if (statusCode >= 600)
throw ResponseException(response)
handleResponseException cause: Throwable ->
throw cause
override suspend fun getUsers(): List<User>
try
return httpClient.get("some url....")
catch (e: Exception)
//*** We get here in case of 404 (for example), but I don't want to repeat it in every request ***/
println(e.message)
return emptyList()
【问题讨论】:
你在你的HttpClient中设置expectSuccess = false
了吗?这可能是您在 ResponseObserver/Validator 中仅获得 200 的原因。
【参考方案1】:
我已经用这个示例类(从official ktor github rep 获取和修改)测试了你的场景,我可以在你想要获取错误代码的所有断点处(例如500
)
package com.example.kmmtest001.shared
import io.ktor.client.*
import io.ktor.client.features.*
import io.ktor.client.features.json.*
import io.ktor.client.features.json.serializer.*
import io.ktor.client.features.observer.*
import io.ktor.client.request.*
import io.ktor.client.statement.*
import io.ktor.http.*
import kotlinx.coroutines.*
internal expect val ApplicationDispatcher: CoroutineDispatcher
class ApplicationApi
private val client = HttpClient
install(JsonFeature)
val json = kotlinx.serialization.json.Json ignoreUnknownKeys = true
serializer = KotlinxSerializer(json)
install(ResponseObserver)
onResponse response ->
println("HTTP status: $response.status.value")
HttpResponseValidator
validateResponse response: HttpResponse ->
val statusCode = response.status.value
println("HTTP status: $statusCode")
when (statusCode)
in 300..399 -> throw RedirectResponseException(response)
in 400..499 -> throw ClientRequestException(response)
in 500..599 -> throw ServerResponseException(response)
if (statusCode >= 600)
throw ResponseException(response)
handleResponseException cause: Throwable ->
throw cause
var address = Url("https://tools.ietf.org/rfc/rfc1866.txt")
fun about(callback: (String) -> Unit)
GlobalScope.apply
launch(ApplicationDispatcher)
val result: String = client.get
url(this@ApplicationApi.address.toString())
callback(result)
fun get500ServerError(callback: (String) -> Unit)
GlobalScope.apply
launch(ApplicationDispatcher)
try
val result: String = client.get
url("https://www.versionestabile.it/_sw/so/63812313/index500.php")
callback(result)
catch (se: ServerResponseException)
val statusCode = se.response?.status?.value
callback("HTTP status code: $statusCode --> $se.message")
catch (ce: ClientRequestException)
val statusCode = ce.response?.status?.value
callback("HTTP status code: $statusCode --> $ce.message")
我还测试了401
和404
错误。
【讨论】:
以上是关于Kotlin Multiplatform - 使用 Ktor 处理响应 http 代码和异常的主要内容,如果未能解决你的问题,请参考以下文章
如何在 Kotlin Multiplatform(纯 kotlin)中进行延迟
在 Kotlin Multiplatform 中使用 Swift 协议默认实现
Kotlin Multiplatform Cocoapods 集成问题
如何使用 Cocoapods 调整 Kotlin Multiplatform 项目的 Swift 类名?