Play 2.5 Migration: com.google.inject.CreationException: Unable to create injector

Question

我尝试按照官方迁移指南将我的 Play 2.4.6 项目迁移到 Play 2.5.8：https://www.playframework.com/documentation/2.5.x/Migration25

数据库成功连接后，我收到以下错误消息（完整堆栈跟踪）：

[info] p.a.d.DefaultDBApi - Database [default] connected at XXX;
[error] application - 

! @71in3ncdp - Internal server error, for (GET) [/de] ->

play.api.UnexpectedException: Unexpected exception[CreationException: Unable to create injector, see the following errors:

1) Error in custom provider, java.lang.NullPointerException
  while locating play.api.db.evolutions.ApplicationEvolutionsProvider
  at play.api.db.evolutions.EvolutionsModule.bindings(EvolutionsModule.scala:22):
Binding(class play.api.db.evolutions.ApplicationEvolutions to ProviderConstructionTarget(class play.api.db.evolutions.ApplicationEvolutionsProvider) eagerly) (via modules: com.google.inject.util.Modules$OverrideModule -> play.api.inject.guice.GuiceableModuleConversions$$anon$1)
  while locating play.api.db.evolutions.ApplicationEvolutions

1 error]
    at play.core.server.DevServerStart$$anonfun$mainDev$1$$anon$1$$anonfun$get$1$$anonfun$apply$1$$anonfun$1.apply(DevServerStart.scala:180)
    at play.core.server.DevServerStart$$anonfun$mainDev$1$$anon$1$$anonfun$get$1$$anonfun$apply$1$$anonfun$1.apply(DevServerStart.scala:131)
    at scala.Option.map(Option.scala:146)
    at play.core.server.DevServerStart$$anonfun$mainDev$1$$anon$1$$anonfun$get$1$$anonfun$apply$1.apply(DevServerStart.scala:131)
    at play.core.server.DevServerStart$$anonfun$mainDev$1$$anon$1$$anonfun$get$1$$anonfun$apply$1.apply(DevServerStart.scala:129)
    at scala.util.Success.flatMap(Try.scala:231)
    at play.core.server.DevServerStart$$anonfun$mainDev$1$$anon$1$$anonfun$get$1.apply(DevServerStart.scala:129)
    at play.core.server.DevServerStart$$anonfun$mainDev$1$$anon$1$$anonfun$get$1.apply(DevServerStart.scala:121)
    at scala.concurrent.impl.Future$PromiseCompletingRunnable.liftedTree1$1(Future.scala:24)
    at scala.concurrent.impl.Future$PromiseCompletingRunnable.run(Future.scala:24)
Caused by: com.google.inject.CreationException: Unable to create injector, see the following errors:

1) Error in custom provider, java.lang.NullPointerException
  while locating play.api.db.evolutions.ApplicationEvolutionsProvider
  at play.api.db.evolutions.EvolutionsModule.bindings(EvolutionsModule.scala:22):
Binding(class play.api.db.evolutions.ApplicationEvolutions to ProviderConstructionTarget(class play.api.db.evolutions.ApplicationEvolutionsProvider) eagerly) (via modules: com.google.inject.util.Modules$OverrideModule -> play.api.inject.guice.GuiceableModuleConversions$$anon$1)
  while locating play.api.db.evolutions.ApplicationEvolutions

1 error
    at com.google.inject.internal.Errors.throwCreationExceptionIfErrorsExist(Errors.java:466)
    at com.google.inject.internal.InternalInjectorCreator.injectDynamically(InternalInjectorCreator.java:184)
    at com.google.inject.internal.InternalInjectorCreator.build(InternalInjectorCreator.java:110)
    at com.google.inject.Guice.createInjector(Guice.java:96)
    at com.google.inject.Guice.createInjector(Guice.java:84)
    at play.api.inject.guice.GuiceBuilder.injector(GuiceInjectorBuilder.scala:181)
    at play.api.inject.guice.GuiceApplicationBuilder.build(GuiceApplicationBuilder.scala:123)
    at play.api.inject.guice.GuiceApplicationLoader.load(GuiceApplicationLoader.scala:21)
    at play.core.server.DevServerStart$$anonfun$mainDev$1$$anon$1$$anonfun$get$1$$anonfun$apply$1$$anonfun$1$$anonfun$2.apply(DevServerStart.scala:168)
    at play.core.server.DevServerStart$$anonfun$mainDev$1$$anon$1$$anonfun$get$1$$anonfun$apply$1$$anonfun$1$$anonfun$2.apply(DevServerStart.scala:164)
Caused by: java.lang.NullPointerException: null
    at com.avaje.ebean.config.dbplatform.DatabasePlatform.createDdlHandler(DatabasePlatform.java:209)
    at com.avaje.ebean.dbmigration.model.CurrentModel.handler(CurrentModel.java:150)
    at com.avaje.ebean.dbmigration.model.CurrentModel.createDdl(CurrentModel.java:141)
    at com.avaje.ebean.dbmigration.model.CurrentModel.getCreateDdl(CurrentModel.java:107)
    at play.db.ebean.EbeanDynamicEvolutions.generateEvolutionScript(EbeanDynamicEvolutions.java:93)
    at play.db.ebean.EbeanDynamicEvolutions.lambda$create$4(EbeanDynamicEvolutions.java:59)
    at java.util.HashMap.forEach(HashMap.java:1280)
    at play.db.ebean.EbeanDynamicEvolutions.create(EbeanDynamicEvolutions.java:58)
    at play.api.db.evolutions.ApplicationEvolutions.start(ApplicationEvolutions.scala:40)
    at play.api.db.evolutions.ApplicationEvolutions.<init>(ApplicationEvolutions.scala:150)

奇怪的是，我没有使用 Play Evolutions，我什至在 application.conf 中禁用了它：

play.evolutions.enabled=false

Answer 1

我自己解决了这个问题。

必须在配置文件中添加一行来禁用 Evolutions 模块，所以我现在在 application.conf 中有这两行：

play.evolutions.enabled=false
play.modules.disabled += "play.api.db.evolutions.EvolutionsModule"

我真的不明白为什么需要这样做以及为什么 https://www.playframework.com/documentation/2.5.x/Evolutions 中没有记录它

希望它对未来的人有所帮助。