如何异步操作API中戏2.2.x的框架斯卡拉的作品？ [英] How async Action api works in play framework 2.2.x for scala?
问题描述
我试图创建异步API。但反应显示顺序执行。
步骤来完成：在镀铬的两个选项卡中打开URL。赶紧打他们一个其他的了。网址例如： - 本地主机：9000 / getStar
I was trying to create async api. But the response shows sequential execution.
Steps done: Open the url in two tabs of chrome. And hit them one after other quickly. url ex:- localhost:9000/getStar.
但执行日志是这样的： -
But the execution log is like :-
[info] play - Listening for HTTP on /0:0:0:0:0:0:0:0:9000
(Server started, use Ctrl+D to stop and go back to the console...)
[success] Compiled in 107ms
[info] application - Application has started
[info] play - Application started (Dev)
[info] application - Async started ************************** :tarun
[info] application - Success Async call :1
[info] application - Success Async call :2
[info] application - Success Async call :3
[info] application - Success Async call :4
[info] application - Success Async call :5
[info] application - Success Async call :6
[info] application - Success Async call :7
[info] application - Success Async call :8
[info] application - Success Async call :9
[info] application - Async finished ************************** :tarun
[info] application - Async started ************************** :tarun1
[info] application - Success Async call :1
[info] application - Success Async call :2
[info] application - Success Async call :3
[info] application - Success Async call :4
[info] application - Success Async call :5
[info] application - Success Async call :6
[info] application - Success Async call :7
[info] application - Success Async call :8
[info] application - Success Async call :9
[info] application - Async finished ************************** :tarun1
在code这个是：
The code for this is :
package controllers
import play.Logger
import play.api.libs.json.Json
import play.api.mvc._
import scala.concurrent.Future
object StarController extends Controller {
import play.api.libs.concurrent.Execution.Implicits.defaultContext
def getStarAsync(name : String) = Action.async{
val futureResult = Future{
Logger.info("Async started ************************** :" + name)
val a = 0;
for( a <- 1 until 10) {
Thread.sleep(1000)
Logger.info("Success Async call :" + a.toString)
}
Logger.info("Async finished ************************** :" + name)
Map("success" -> Json.toJson(true), "msg" -> Json.toJson("Success Async by :" + name), "code" -> Json.toJson(200))
}
futureResult.map{ result =>
Ok(Json.toJson(result))
}
}
}
谁能帮我明白了，为什么的执行顺序是，即使异步调用？
Can anyone please help me understand , why the execution of the was sequential even with async call ?
推荐答案
Action.async 不会奇迹般地使控制器方法异步的。在仅的事情是它不同的是，它需要一个的未来[结果] 代替结果。而已。控制器是异步的，否则，因为他们可以通过自然（即正常动作被包裹在一个未来反正）。这里的事情是，视频下载（1000）的块的它的线程，是没有一丝异步的。
Action.async doesn't magically make the controller method asynchronous. The only thing it is different about it is that it expects a Future[Result] instead of a Result. That's it. Controllers are otherwise asynchronous as they can be by nature (i.e. a normal Action gets wrapped in a Future anyway). The thing here is that Thread.sleep(1000) blocks it's thread, and is not the least bit asynchronous.
另一件事是，在开发模式（即激活运行），该剧服务器使用一个线程来服务请求，所以它能够妥善处理重载/编译变阵，等等。所以，有什么情况是，你只是用阻塞同步调用该线程。你应该使用激活启动看到不同的结果，但即便如此，也没有一点用 Action.async 在这里，除非你是打算委派阻塞到一个不同的线程池。
The other thing is that in dev mode (i.e. activator run), the play server uses a single thread to serve requests, so it can properly handle reload/compile, evolutions, etc. So what's happening is that you're just blocking that thread with synchronous calls. You should see different results using activator start, but even so, there's no point in using Action.async here unless you're going to delegate that blocking to a different thread pool.
<一个href=\"http://stackoverflow.com/questions/23997418/are-there-any-benefits-in-using-non-async-actions-in-play-framework-2-2/24004444#24004444\">Further 阅读。
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