Play 框架:依赖注入动作生成器 [英] Play Framework: Dependency Inject Action Builder

问题描述

从 Play Framework 2.4 开始，可以使用依赖注入(使用 Guice).

since Play Framework 2.4 there is the possibility to use dependency injection (with Guice).

在我的 ActionBuilders 中使用对象(例如 AuthenticationService)之前:

Before I used objects (for example AuthenticationService) in my ActionBuilders:

object AuthenticatedAction extends ActionBuilder[AuthenticatedRequest] {
  override def invokeBlock[A](request: Request[A], block: (AuthenticatedRequest[A]) => Future[Result]): Future[Result] = {
    ...
    AuthenticationService.authenticate (...)
    ...
  }
}

现在 AuthenticationService 不再是一个对象，而是一个类.我怎样才能在我的 ActionBuilder 中仍然使用 AuthenticationService?

Now AuthenticationService is not an object anymore, but a class. How can I still use the AuthenticationService in my ActionBuilder?

推荐答案

在身份验证服务作为抽象字段的特征中定义您的操作构建器.然后将它们混合到您的控制器中，您将在其中注入服务.例如:

Define your action builders inside a trait with the authentication service as an abstract field. Then mix them into your controllers, into which you inject the service. For example:

trait MyActionBuilders {
  // the abstract dependency
  def authService: AuthenticationService

  def AuthenticatedAction = new ActionBuilder[AuthenticatedRequest] {
    override def invokeBlock[A](request: Request[A], block(AuthenticatedRequest[A]) => Future[Result]): Future[Result] = {
      authService.authenticate(...)
      ...
    }
  }
}

和控制器:

@Singleton
class MyController @Inject()(authService: AuthenticationService) extends Controller with MyActionBuilders {    
  def myAction(...) = AuthenticatedAction { implicit request =>
    Ok("authenticated!")
  }
}

这篇关于Play 框架:依赖注入动作生成器的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！