在playframework中設置像這樣的GLOBAL變量是否是一個好習慣？

我見過這樣的代碼在app/Global.scala，這是由我的同事寫在playframework中設置像這樣的GLOBAL變量是否是一個好習慣？

import java.lang.reflect.Constructor 
import securesocial.core.RuntimeEnvironment 
import securesocial.core.providers._ 
import securesocial.core.providers.utils.Mailer 
import services.UserService 

import scala.collection.immutable.ListMap 

object Global extends play.api.GlobalSettings { 

    /** 
    * The runtime environment for this app. 
    */ 
    object MyRuntimeEnvironment extends RuntimeEnvironment.Default[User] { 
    // override lazy val routes = new CustomRoutesService() 
    override lazy val userService: UserService = new UserService() 
    lazy val MailTemplates: MailTemplates = new MailTemplates(this) 
    override lazy val mailer: Mailer = new Mailer(MailTemplates) 
    // override lazy val eventListeners = List(new MyEventListener()) 
    override lazy val providers = ListMap(
     // oauth 2 client providers 
     include(new FacebookProvider(routes, cacheService, oauth2ClientFor(FacebookProvider.Facebook))), 
     // username password 
     include(new UsernamePasswordProvider(userService, avatarService, passwordHashers)) 
    ) 
    } 

    /** 
    * An implementation that checks if the controller expects a RuntimeEnvironment and 
    * passes the instance to it if required. 
    * 
    * This can be replaced by any DI framework to inject it differently. 
    * 
    * @param controllerClass 
    * @tparam A 
    * @return 
    */ 
    override def getControllerInstance[A](controllerClass: Class[A]): A = { 
    val instance = controllerClass.getConstructors.find { c => 
     val params = c.getParameterTypes 
     params.length == 1 && params(0) == classOf[RuntimeEnvironment[User]] 
    }.map { 
     _.asInstanceOf[Constructor[A]].newInstance(MyRuntimeEnvironment) 
    } 
    instance.getOrElse(super.getControllerInstance(controllerClass)) 
    } 
}

有誰認爲這是合適的設置服務在全球playframework值？

來源

2015-01-07 Hanfei Sun