玩：如何用DI替换`Play.current`？

Question

在尝试编写测试时，我从 Play 收到此警告：

You do not have an implicit Application in scope. If you want to bring the current running Application into context, please use dependency injection.

我发现如果我添加这个导入，它神奇地 解决了范围内应用程序的问题：

import play.api.Play.current

但是它会警告您

method current in object Play is deprecated: This is a static reference to application, use DI instead

如何使用依赖注入获得相同的结果？这是我需要的地方：

class TestSpec extends PlaySpec with OneAppPerSuite { ... }

编辑：我确实找到了 this post，但我不明白答案如何为我提供获得 implicit Application.

Answer 1

有人向我指出了 this example（来自 @insan-e），它展示了如何解决这个问题。您无法注入测试 class，但您 "only" 需要用此覆盖您的 PlaySpec：

import javax.inject.{Inject, Singleton}
import org.scalatestplus.play.{OneAppPerSuite, PlaySpec}
import play.api.Application
import play.api.inject.guice.GuiceApplicationBuilder

// To avoid repeating the `instanceCache` line below for each DAO
@Singleton
class DaoContext @Inject()(
                        val testDAO: TestDAO
                        // Other DAOs here
)

abstract class BetterSpec extends PlaySpec with OneAppPerSuite {
  implicit override lazy val app = new GuiceApplicationBuilder().configure(...).build

  protected def daoContext(implicit app: Application): DaoContext = {
    Application.instanceCache[DaoContext].apply(app)
  }
}

和测试：

class TestSpec extends BetterSpec {
  "Test DAO" should {
    "work" in {
      val dao = daoContext.testDAO
      // test it, finally
    }
  }
}

我知道，"what the hell????"但它奏效了。

N.B。现在它可以作为

的副本关闭

玩：如何用DI替换`Play.current`？

Play: How to replace `Play.current` with DI?

scala

playframework

playframework-2.0