Play 2.4 测试出错：CacheManager 已关闭。不能再使用了

Question

我们的应用程序基于 Play 2.4 与 Scala 2.11 和 Akka。使用的数据库是 MySQL.

在我们的 application.We 中大量使用缓存，使用 Play 的默认 EhCache 进行缓存。

我们的示例代码片段：

import play.api.Play.current
import play.api.cache.Cache

case class Sample(var id: Option[String],
                 //.. other fields
)

class SampleTable(tag: Tag)
  extends Table[Sample](tag, "SAMPLE") {
  def id = column[Option[String]]("id", O.PrimaryKey)
  // .. other field defs
}

object SampleDAO extends TableQuery(new SampleTable(_)) with SQLWrapper {
  def get(id: String) : Future[Sample] = {
    val cacheKey = // our code to generate a unique cache key
    Cache.getOrElse[Future[[Sample]](cacheKey) {
      db.run(this.filter(_.id === id).result.headOption)
    }
  }
}

我们使用 Play 的内置 Specs2 进行测试。

var id = "6879a389-aa3c-4074-9929-cca324c7a01f"

  "Sample Application " should {
    "Get a Sample" in new WithApplication {
      val req = FakeRequest(GET, s"/v1/samples/$id")
      val result = route(req).get
      assertEquals(OK, status(result))
      id = (contentAsJson(result).\("id")).get.toString().replaceAllLiterally("\"", "")
   }

但是在单元测试的时候我们经常遇到下面的错误。

[error]    1) Error in custom provider, java.lang.IllegalStateException: The  CacheManager has been shut down. It can no longer b
e used.
[error]      at play.api.cache.EhCacheModule.play$api$cache$EhCacheModule$$bindCache(Cache.scala:181):
[error]    Binding(interface net.sf.ehcache.Ehcache qualified with QualifierInstance(@play.cache.NamedCache(value=play)) to Prov
iderTarget(play.api.cache.NamedEhCacheProvider@7c8b0968)) (via modules: com.google.inject.util.Modules$OverrideModule -> play.ap
i.inject.guice.GuiceableModuleConversions$$anon)
[error]      while locating net.sf.ehcache.Ehcache annotated with @play.cache.NamedCache(value=play)
[error]      at play.api.cache.EhCacheModule.play$api$cache$EhCacheModule$$bindCache(Cache.scala:182):
[error]    Binding(interface play.api.cache.CacheApi qualified with QualifierInstance(@play.cache.NamedCache(value=play)) to Pro
viderTarget(play.api.cache.NamedCacheApiProvider@38514c74)) (via modules: com.google.inject.util.Modules$OverrideModule -> play.
api.inject.guice.GuiceableModuleConversions$$anon)
[error]      while locating play.api.cache.CacheApi annotated with @play.cache.NamedCache(value=play)
[error]      while locating play.api.cache.CacheApi
[error]
[error]    1 error (InjectorImpl.java:1025)
[error] com.google.inject.internal.InjectorImpl.get(InjectorImpl.java:1025)
[error] com.google.inject.internal.InjectorImpl.getInstance(InjectorImpl.java:1051)
[error] play.api.inject.guice.GuiceInjector.instanceOf(GuiceInjectorBuilder.scala:321)
[error] play.api.inject.guice.GuiceInjector.instanceOf(GuiceInjectorBuilder.scala:316)
[error] play.api.Application$$anonfun$instanceCache.apply(Application.scala:234)
[error] play.api.Application$$anonfun$instanceCache.apply(Application.scala:234)
[error] play.utils.InlineCache.fresh(InlineCache.scala:69)
[error] play.utils.InlineCache.apply(InlineCache.scala:62)
[error] play.api.cache.Cache$.cacheApi(Cache.scala:63)
[error] play.api.cache.Cache$.getOrElse(Cache.scala:106

我们期待帮助解决上述问题或实现专门用于测试的模拟缓存的方法。

提前致谢。

Answer 1

我遇到了类似的问题，所以我删除了一个缓存实现并将其换入以进行测试。

class FakeCache extends CacheApi {
  override def set(key: String, value: Any, expiration: Duration): Unit = {}

  override def get[T](key: String)(implicit evidence: ClassManifest[T]): Option[T] = None

  override def getOrElse[A](key: String, expiration: Duration)(orElse: => A)(implicit evidence: ClassManifest[A]): A = orElse

  override def remove(key: String): Unit = {}
}

覆盖注入：

class AbstractViewTest extends PlaySpecification {

  def testApp(handler: DeadboltHandler): Application = new GuiceApplicationBuilder()
                                                   .overrides(bind[CacheApi].to[FakeCache])
                                                   .in(Mode.Test)
                                                   .build()

}

你可以在 GitHub 上看到我是如何使用它的：https://github.com/schaloner/deadbolt-2-scala/blob/master/code/test/be/objectify/deadbolt/scala/views/AbstractViewTest.scala

Answer 2

另一个解决方案是在每次测试开始时调用 sequential 方法。

class MySpec extends Specification {
  sequential

  ...
}

备注

parallelExecution in Test := false

也应该在 build.sbt 文件中设置。

Answer 3

我认为通过伪造缓存来绕过缓存测试是一种不好的做法。它会使您的测试无效，所有这些都是因为您试图不以可扩展和分布式的方式使用 EhCache。更好的方法是实现一个 @Singleton 接口，详见此处：

感谢https://whosebug.com/users/2145368/mon-calamari

Play 2.4 测试出错：CacheManager 已关闭。不能再使用了

Error with Play 2.4 Tests : The CacheManager has been shut down. It can no longer be used

junit

caching

ehcache

scala-2.11

playframework-2.4