Package au.csiro.pathling.utilities

Interface ObjectHolder<C extends Serializable,V>

Type Parameters:
C - the type of the configuration
V - the type of the instance
All Known Implementing Classes:
ObjectHolder.SingletonHolder
public interface ObjectHolder<C extends Serializable,V>
Represents a scoped storage for instances of type V that can be created from configuration of type C. The concrete implementations can use various strategies for storing the instances. For example a singleton can manage a single instance per process.
Author:
Piotr Szul

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Interface
    Description
    static class 
    ObjectHolder.SingletonHolder<C extends Serializable,V>
    A singleton implementation of ObjectHolder that holds a single instance of something.

  • Method Summary

    Modifier and Type
    Method
    Description
    V
    getOrCreate(C config)
    Retrieves the instance associated with given configuration and if necessary creates ones.
    void
    reset()
    Destroys all the instances stored the underlying scope.
    static <C extends Serializable, V>
    ObjectHolder<C,V>
    singleton(Function<C,V> constructor)
    Creates the holder allowing a single instance to be created per process.
    static <C extends Serializable, V>
    ObjectHolder<C,V>
    singleton(Function<C,V> constructor, boolean closeOnShutdown, int shutdownHookPriority)
    Creates the holder allowing a single instance to be created per process.

  • Method Details

    • getOrCreate

      V getOrCreate(@Nonnull C config)
      Retrieves the instance associated with given configuration and if necessary creates ones.
      Parameters:
      config - the configuration for the instance.
      Returns:
      the instance associated with the holder.

    • reset

      void reset()
      Destroys all the instances stored the underlying scope.

    • singleton

      static <C extends Serializable, V> ObjectHolder<C,V> singleton(@Nonnull Function<C,V> constructor, boolean closeOnShutdown, int shutdownHookPriority)
      Creates the holder allowing a single instance to be created per process. Attempts to create another instance with different configuration will fail.
      Type Parameters:
      C - the type of the configuration.
      V - the type of the instance.
      Parameters:
      constructor - the function that creates new instance from the configuration.
      closeOnShutdown - whether to close the instance on JVM shutdown.
      shutdownHookPriority - the priority of the shutdown hook.
      Returns:
      the singleton holder.

    • singleton

      static <C extends Serializable, V> ObjectHolder<C,V> singleton(@Nonnull Function<C,V> constructor)
      Creates the holder allowing a single instance to be created per process. Attempts to create another instance with different configuration will fail. The instance will be closed on JVM shutdown.
      Type Parameters:
      C - the type of the configuration.
      V - the type of the instance.
      Parameters:
      constructor - the function that creates new instance from the configuration.
      Returns:
      the singleton holder.