Interface Producer<I>

Type Parameters:

I - the type of contextual instance

All Superinterfaces:

Aggregate

All Known Implementing Classes:

InterceptingProducer

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public interface Producer<I>
extends Aggregate

An interface whose implementations produce possibly uninitialized contextual instances.

Producers are used to implement Factory instances' create(Request) and destroy(Object, Request) methods. Values returned from the produce(Request) method are often supplied to Initializers.

Author:

Laird Nelson

See Also:

• produce(Request)
• Factory.create(Request)

Field Summary

Fields inherited from interface org.microbean.bean.Aggregate

EMPTY_ASSIGNMENTS, EMPTY_DEPENDENCIES

Method Summary

Modifier and Type	Method	Description
default void	dispose(I i, Request<I> r)	Disposes of the supplied contextual instance.
I	produce(SequencedSet<? extends Assignment<?>> assignments)	Produces a new contextual instance and returns it, possibly (often) making use of the supplied, dependent, contextual references.
default I	produce(Request<?> r)	Produces a new contextual instance and returns it by calling the produce(SequencedSet) method with the return value of an invocation of the Aggregate.assign(Request) method with the supplied Request.

Methods inherited from interface org.microbean.bean.Aggregate

assign, dependencies

Method Details

dispose

default void dispose(I i,
 Request<I> 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 DestructionException.

Parameters:

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

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

Throws:

NullPointerException - if r is null

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

produce

default I produce(Request<?> r)

Produces a new contextual instance and returns it by calling the produce(SequencedSet) method with the return value of an invocation of the Aggregate.assign(Request) method with the supplied Request.

Parameters:

r - a Request; must not be null

Returns:

a new contextual instance, or null

Throws:

NullPointerException - if r is null

See Also:

• produce(SequencedSet)
• Aggregate.assign(Request)

produce

I produce(SequencedSet<? extends Assignment<?>> assignments)

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

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

Parameters:

assignments - a SequencedSet of Assignments this Producer needs to create the contextual instance; must not be null

Returns:

a new contextual instance, or null

Throws:

NullPointerException - if dependentContextualReferences is null