第一次使用协同程序。需要帮忙。
这是我的流程:
Presenter想要登录,因此调用Repository Interface。存储库实现RepositoryInterface。所以Repository调用APIInterface。 APIInterface由APIInterfaceImpl实现。 APIInterfaceImpl最终调用MyRetrofitInterface。
以下是流程图:
Presenter - > Repository - > APIInterfaceImpl - > MyRetrofitInterface
一旦我得到登录回复:
APIInterfaceImpl - > Repository - >将数据存储在缓存中 - >将http状态代码提供给Presenter
这是我的代码:
RepositoryInterface.kt
fun onUserLogin(loginRequest: LoginRequest): LoginResponse
Repository.kt
class Repository : RepositoryInterface {
private var apiInterface: APIInterface? = null
override fun onUserLogin(loginRequest: LoginRequest): LoginResponse {
return apiInterface?.makeLoginCall(loginRequest)
}
}
APIInterface.kt
suspend fun makeLoginCall(loginRequest): LoginResponse?
APIInterfaceImpl.kt
override suspend fun makeLoginCall(loginRequest: LoginRequest): LoginResponse? {
if (isInternetPresent(context)) {
try {
val response = MyRetrofitInterface?.loginRequest(loginRequest)?.await()
return response
} catch (e: Exception) {
//How do i return a status code here
}
} else {
//How do i return no internet here
return Exception(Constants.NO_INTERNET)
}
}
MyRetrofitInterface.kt
@POST("login/....")
fun loginRequest(@Body loginRequest: LoginRequest): Deferred<LoginResponse>?
我的问题是:
在本地范围内启动协程是一种很好的做法,可以在生命周期感知类中实现,例如Presenter或ViewModel。您可以使用下一种方法传递数据:
sealed
Result
类及其继承者:
sealed class Result<out T : Any>
class Success<out T : Any>(val data: T) : Result<T>()
class Error(val exception: Throwable, val message: String = exception.localizedMessage) : Result<Nothing>()
onUserLogin
函数可暂停并返回Result
和RepositoryInterface
中的Repository
:
suspend fun onUserLogin(loginRequest: LoginRequest): Result<LoginResponse> {
return apiInterface.makeLoginCall(loginRequest)
}
makeLoginCall
和APIInterface
中的APIInterfaceImpl
函数:
suspend fun makeLoginCall(loginRequest: LoginRequest): Result<LoginResponse> {
if (isInternetPresent()) {
try {
val response = MyRetrofitInterface?.loginRequest(loginRequest)?.await()
return Success(response)
} catch (e: Exception) {
return Error(e)
}
} else {
return Error(Exception(Constants.NO_INTERNET))
}
}
Presenter
的下一个代码:
class Presenter(private val repo: RepositoryInterface,
private val uiContext: CoroutineContext = Dispatchers.Main
) : CoroutineScope { // creating local scope
private var job: Job = Job()
// To use Dispatchers.Main (CoroutineDispatcher - runs and schedules coroutines) in Android add
// implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.0.1'
override val coroutineContext: CoroutineContext
get() = uiContext + job
fun detachView() {
// cancel the job when view is detached
job.cancel()
}
fun login() = launch { // launching a coroutine
val request = LoginRequest()
val result = repo.onUserLogin(request) // onUserLogin() function isn't blocking the Main Thread
//use result, make UI updates
when (result) {
is Success<LoginResponse> -> { /* update UI when login success */ }
is Error -> { /* update UI when login error */ }
}
}
}
我对这个话题有很多想法并提出了解决方案。我认为这个解决方案更清洁,易于处理异常。首先使用写代码时
fun getNames() = launch { }
您正在将工作实例返回给我,我认为这是不正确的。用户不应该参考工作实例。我尝试了以下解决方案,它对我有用。但我想讨论是否会出现任何副作用。感谢您的评论。
fun main() {
Presenter().getNames()
Thread.sleep(1000000)
}
class Presenter(private val repository: Repository = Repository()) : CoroutineScope {
private val job = Job()
override val coroutineContext: CoroutineContext
get() = job + Dispatchers.Default // Can be Dispatchers.Main in Android
fun getNames() = launchSafe(::handleLoginError) {
println(repository.getNames())
}
private fun handleLoginError(throwable: Throwable) {
println(throwable)
}
fun detach() = this.cancel()
}
class Repository {
suspend fun getNames() = suspendCancellableCoroutine<List<String>> {
val timer = Timer()
it.invokeOnCancellation {
timer.cancel()
}
timer.schedule(timerTask {
it.resumeWithException(IllegalArgumentException())
//it.resume(listOf("a", "b", "c", "d"))
}, 500)
}
}
fun CoroutineScope.launchSafe(
onError: (Throwable) -> Unit = {},
onSuccess: suspend () -> Unit
) {
val handler = CoroutineExceptionHandler { _, throwable ->
onError(throwable)
}
launch(handler) {
onSuccess()
}
}