10

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

我们的应用程序中大量使用缓存。我们使用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("\"", "")
   }

但是在进行单元测试时，我们经常会遇到以下错误。

[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$$bindCache$1(Cache.scala:181):
[error]    Binding(interface net.sf.ehcache.Ehcache qualified with QualifierInstance(@play.cache.NamedCache(value=play)) to Prov
iderTarget(play.api.cache.NamedEhCacheProvider@7c8b0968)) (via modules: com.google.inject.util.Modules$OverrideModule -> play.ap
i.inject.guice.GuiceableModuleConversions$$anon$1)
[error]      while locating net.sf.ehcache.Ehcache annotated with @play.cache.NamedCache(value=play)
[error]      at play.api.cache.EhCacheModule.play$api$cache$EhCacheModule$$bindCache$1(Cache.scala:182):
[error]    Binding(interface play.api.cache.CacheApi qualified with QualifierInstance(@play.cache.NamedCache(value=play)) to Pro
viderTarget(play.api.cache.NamedCacheApiProvider@38514c74)) (via modules: com.google.inject.util.Modules$OverrideModule -> play.
api.inject.guice.GuiceableModuleConversions$$anon$1)
[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$2.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$$anonfun$instanceCache$1.apply(Application.scala:234)
[error] play.api.Application$$anonfun$instanceCache$1.apply(Application.scala:234)
[error] play.utils.InlineCache.fresh(InlineCache.scala:69)
[error] play.utils.InlineCache.apply(InlineCache.scala:62)
[error] play.api.cache.Cache$.cacheApi(Cache.scala:63)
[error] play.api.cache.Cache$.getOrElse(Cache.scala:106

我们期待有关解决上述问题或专门为测试实现模拟缓存的方法的帮助。

提前致谢。

4

3 回答 3

5

我有一个类似的问题，所以我删除了一个缓存实现并将其换成测试。

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

  override def get[T](key: String)(implicit evidence$2: ClassManifest[T]): Option[T] = None

  override def getOrElse[A](key: String, expiration: Duration)(orElse: => A)(implicit evidence$1: 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

于 2015-06-26T10:25:03.157 回答
3

另一种解决方案是在每次测试开始时调用该sequential方法。

class MySpec extends Specification {
  sequential

  ...
}

笔记

parallelExecution in Test := false

也应该在build.sbt文件中设置。

于 2015-08-24T10:51:08.020 回答
1

我认为通过伪造缓存来绕过缓存测试是一种不好的做法。它使您的测试无效，这一切都是因为您试图不以可扩展和分布式的方式使用 EhCache。一个更好的方法是实现一个@Singleton 接口，详见此处：https ://stackoverflow.com/a/31835029/5736587

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

于 2016-01-01T19:30:19.753 回答