[英]Inject DatabaseConfigProvider with macwire
我试图将Slick添加到我的项目中
创建RoomRepo类
class RoomRepo @Inject() (dbConfigProvider: DatabaseConfigProvider)(implicit ec: ExecutionContext) extends HasDatabaseConfigProvider[JdbcProfile]{/**...*/}
注入它
class ChatEngine @Inject()(dbRoom: RoomRepo)(socketIO: SocketIO)(implicit mat: Materializer){/**...*/}
ChatEngine装有macwire
trait MyApplication extends BuiltInComponents
with AssetsComponents
with SocketIOComponents {
lazy val dbConfigProvider = wire[DatabaseConfigProvider.get[JdbcProfile]]
lazy val dbRoom = wire[RoomRepo]
lazy val chatEngine = wire[ChatEngine]
lazy val engineIOController: EngineIOController = chatEngine.controller
override lazy val router = {
val prefix = "/"
wire[_root_.router.Routes]
}
override lazy val httpFilters = Nil
}
然后我得到这个错误:
[错误] /MyApplicationLoader.scala:31:59:类型get不是对象play.api.db.slick.DatabaseConfigProvider的成员
[错误]延迟val dbConfigProvider = wire [DatabaseConfigProvider.get [JdbcProfile]]
[错误] ^ [错误] /MyApplicationLoader.scala:32:25:找不到以下类型的值:[play.api.db.slick.DatabaseConfigProvider]
[错误]懒val dbRoom =电线[RoomRepo]
[错误] ^ [错误] /MyApplicationLoader.scala:33:29:找不到类型的值:[models.RoomRepo]
[错误]懒惰的val chatEngine =电线[ChatEngine]
通过扩展SlickComponents
可以使用play- slick通过SlickComponents
实施编译时依赖项注入
如果使用的是编译时DI,则可以使用
slickApi.dbConfig(DbName(name))
方法直接从SlickApi
查询数据库配置。play.api.db.slick.SlickComponents
提供对slickApi
访问。
像这样
trait DatabaseComponents extends SlickComponents {
implicit def ec: ExecutionContext
lazy val dbConfig = slickApi.dbConfig[JdbcProfile](DbName("default"))
lazy val roomRepo: RoomRepo = wire[RoomRepo]
}
注意DbName("default")
引用application.conf
default
数据库,例如
slick.dbs.default.profile="slick.jdbc.H2Profile$"
slick.dbs.default.db.profile="org.h2.Driver"
slick.dbs.default.db.url="jdbc:h2:mem:play;DB_CLOSE_DELAY=-1"
修改RoomRepo
以采用DatabaseConfig
而不是DatabaseConfigProvider
如下所示
class RoomRepo(dbConfig: DatabaseConfig[JdbcProfile]))(implicit ec: ExecutionContext) ...
和mixin这样的DatabaseComponents
trait MyApplication
extends BuiltInComponents
with AssetsComponents
with SocketIOComponents
with DatabaseComponents {
...
implicit val ec: ExecutionContext = scala.concurrent.ExecutionContext.Implicits.global
}
再说几句话:
@Inject
与macwire混合使用,因为前者用于运行时依赖注入,而后者则用于编译时DI。 wire
的签名是def wire[T]: T
,其中T
必须是在编译时解析的类型,而DatabaseConfigProvider.get[JdbcProfile]
是运行时值,因此, wire[DatabaseConfigProvider.get[JdbcProfile]]
将不会编译。
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