Trait

play.api.inject

ApplicationLifecycle

Related Doc: package inject

Permalink

trait ApplicationLifecycle extends AnyRef

Application lifecycle register.

This is used to hook into Play lifecycle events, specifically, when Play is stopped. The reason Play only provides lifecycle callbacks for stopping is that constructors are considered the application start callback. This has several advantages:

- It simplifies implementation, if you want to start something, just do it in the constructor. - It simplifies state, there's no transitional state where an object has been created but not started yet. Hence, as long as you have a reference to something, it's safe to use it. - It solves startup dependencies in a type safe manner - the order that components must be started is enforced by the order that they must be instantiated due to the component graph.

Stop hooks are executed when the application is shutdown, in reverse from when they were registered. Due to this reverse ordering, a component can know that it is safe to use the components it depends on as long as it hasn't received a shutdown event.

To use this, declare a dependency on ApplicationLifecycle, and then register the stop hook when the component is started. For example:

import play.api.inject.ApplicationLifecycle
import javax.inject.Inject

class SomeDatabase @Inject() (applicationLifecycle: ApplicationLifecycle) {

  private val connectionPool = new SomeConnectionPool()
  applicationLifecycle.addStopHook { () =>
    Future.successful(connectionPool.shutdown())
  }

  ...
}
Source
ApplicationLifecycle.scala
Linear Supertypes
AnyRef, Any
Known Subclasses
Ordering
  1. Alphabetic
  2. By Inheritance
Inherited
  1. ApplicationLifecycle
  2. AnyRef
  3. Any
  1. Hide All
  2. Show All
Visibility
  1. Public
  2. All

Abstract Value Members

  1. abstract def addStopHook(hook: () ⇒ Future[_]): Unit

    Permalink

    Add a stop hook to be called when the application stops.

    Add a stop hook to be called when the application stops.

    The stop hook should redeem the returned future when it is finished shutting down. It is acceptable to stop immediately and return a successful future.

  2. abstract def stop(): Future[_]

    Permalink

    Call to shutdown the application and execute the registered hooks.

    Call to shutdown the application and execute the registered hooks.

    returns

    A future that will be redeemed once all hooks have executed.

Concrete Value Members

  1. final def !=(arg0: Any): Boolean

    Permalink
    Definition Classes
    AnyRef → Any
  2. final def ##(): Int

    Permalink
    Definition Classes
    AnyRef → Any
  3. final def ==(arg0: Any): Boolean

    Permalink
    Definition Classes
    AnyRef → Any
  4. def addStopHook(hook: Callable[_ <: CompletionStage[_]]): Unit

    Permalink

    Add a stop hook to be called when the application stops.

    Add a stop hook to be called when the application stops.

    The stop hook should redeem the returned future when it is finished shutting down. It is acceptable to stop immediately and return a successful future.

  5. final def asInstanceOf[T0]: T0

    Permalink
    Definition Classes
    Any
  6. def asJava: inject.ApplicationLifecycle

    Permalink

    returns

    the Java version for this Application Lifecycle.

  7. def clone(): AnyRef

    Permalink
    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  8. final def eq(arg0: AnyRef): Boolean

    Permalink
    Definition Classes
    AnyRef
  9. def equals(arg0: Any): Boolean

    Permalink
    Definition Classes
    AnyRef → Any
  10. def finalize(): Unit

    Permalink
    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] )
  11. final def getClass(): Class[_]

    Permalink
    Definition Classes
    AnyRef → Any
  12. def hashCode(): Int

    Permalink
    Definition Classes
    AnyRef → Any
  13. final def isInstanceOf[T0]: Boolean

    Permalink
    Definition Classes
    Any
  14. final def ne(arg0: AnyRef): Boolean

    Permalink
    Definition Classes
    AnyRef
  15. final def notify(): Unit

    Permalink
    Definition Classes
    AnyRef
  16. final def notifyAll(): Unit

    Permalink
    Definition Classes
    AnyRef
  17. final def synchronized[T0](arg0: ⇒ T0): T0

    Permalink
    Definition Classes
    AnyRef
  18. def toString(): String

    Permalink
    Definition Classes
    AnyRef → Any
  19. final def wait(): Unit

    Permalink
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  20. final def wait(arg0: Long, arg1: Int): Unit

    Permalink
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  21. final def wait(arg0: Long): Unit

    Permalink
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )

Inherited from AnyRef

Inherited from Any

Ungrouped