Interface Producer<I>

Type Parameters:

I - the contextual instance type

All Superinterfaces:

org.microbean.assign.Aggregate

All Known Implementing Classes:

InterceptingProducer

public interface Producer<I>
extends org.microbean.assign.Aggregate

An interface whose implementations produce and commonly initialize contextual instances.

Producers are used to implement Factory instances' create(Creation) and destroy(Object, Destruction) methods.

A Producer normally initializes the contextual instances it produces as part of its produce(Creation) method implementation, but is not required to.

Author:

Laird Nelson

See Also:

• produce(Creation)
• dependencies()
• dispose(Object, Destruction)
• Factory.create(Creation)

Field Summary

Fields inherited from interface org.microbean.assign.Aggregate

EMPTY_ASSIGNMENTS, EMPTY_DEPENDENCIES

Method Summary

Modifier and Type	Method	Description
default SequencedSet<org.microbean.assign.AttributedElement>	dependencies()	A convenience method that returns an immutable, determinate SequencedSet of AttributedElements consisting of this Producer's production dependencies followed by its initialization dependencies.
default void	dispose(I i, Destruction r)	Disposes of the supplied contextual instance.
SequencedSet<org.microbean.assign.AttributedElement>	initializationDependencies()	Returns an immutable, determinate SequencedSet of AttributedElements representing dependencies required for initialization.
default I	produce(Creation<I> c)	Produces a new contextual instance and returns it by calling the produce(Id, SequencedSet) method with the return value of an invocation of the Aggregate.assign(Function) method with a reference to the supplied Creation's reference(AttributedType) method.
I	produce(Id id, SequencedSet<? extends org.microbean.assign.Assignment<?>> assignments)	Produces a new contextual instance and returns it, possibly (often) making use of the supplied assignments.
SequencedSet<org.microbean.assign.AttributedElement>	productionDependencies()	Returns an immutable, determinate SequencedSet of AttributedElements representing dependencies required for production.

Methods inherited from interface org.microbean.assign.Aggregate

assign

Method Details

dependencies

default SequencedSet<org.microbean.assign.AttributedElement> dependencies()

A convenience method that returns an immutable, determinate SequencedSet of AttributedElements consisting of this Producer's production dependencies followed by its initialization dependencies.

There is normally no need to override the default implementation of this method.

Specified by:

dependencies in interface org.microbean.assign.Aggregate

Returns:

a non-null, immutable, determinate SequencedSet of AttributedElements consisting of this Producer's production dependencies followed by its initialization dependencies

See Also:

• productionDependencies()
• initializationDependencies()

dispose

default void dispose(I i,
 Destruction r)

Disposes of the supplied contextual instance.

The default implementation of this method checks to see if i is an instance of AutoCloseable, and, if so, calls close() on it, throwing any resulting exception as a DisposalException.

Parameters:

i - a contextual instance produced by this Producer; may be null

r - the Creation that was present at production time; must not be null

Throws:

NullPointerException - if r is null

DisposalException - if i is an AutoCloseable instance, and if its close() method throws a checked exception

initializationDependencies

SequencedSet<org.microbean.assign.AttributedElement> initializationDependencies()

Returns an immutable, determinate SequencedSet of AttributedElements representing dependencies required for initialization.

Such dependencies may represent initialization method parameters and/or fields.

Contrast initialization dependencies with production dependencies.

Returns:

a non-null, immutable, determinate SequencedSet of AttributedElements representing dependencies required for initialization

See Also:

• productionDependencies()

produce

default I produce(Creation<I> c)

Produces a new contextual instance and returns it by calling the produce(Id, SequencedSet) method with the return value of an invocation of the Aggregate.assign(Function) method with a reference to the supplied Creation's reference(AttributedType) method.

There is normally no need to override the default implementation of this method.

Parameters:

c - a Creation; must not be null

Returns:

a new contextual instance, or null

Throws:

NullPointerException - if c is null

See Also:

• produce(Id, SequencedSet)
• dependencies()

produce

I produce(Id id,
 SequencedSet<? extends org.microbean.assign.Assignment<?>> assignments)

Produces a new contextual instance and returns it, possibly (often) making use of the supplied assignments.

Implementations of this method must not call produce(Creation) or an infinite loop may result.

Parameters:

id - an Id for which production is occurring; must not be null

assignments - a SequencedSet of Assignments this Producer needs to complete production and possibly initialization; must not be null

Returns:

a new contextual instance, or null

Throws:

NullPointerException - if assignments is null

productionDependencies

SequencedSet<org.microbean.assign.AttributedElement> productionDependencies()

Returns an immutable, determinate SequencedSet of AttributedElements representing dependencies required for production.

Such dependencies normally represent constructor parameters.

Contrast production dependencies with initialization dependencies.

Returns:

a non-null, immutable, determinate SequencedSet of AttributedElements representing dependencies required for production

See Also:

• initializationDependencies()