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>

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 Detail

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.