Record Class Constant<I>

java.lang.Object

java.lang.Record

org.microbean.bean.Constant<I>

Type Parameters:

I - the singleton type

Record Components:

singleton - the singleton

All Implemented Interfaces:

Constable, Aggregate, Factory<I>

public record Constant<I>(I singleton)
extends Record
implements Constable, Factory<I>

A Factory that returns its singleton from its create(Request) method.

Author:

Laird Nelson

See Also:

• singleton()
• create(Request)

Field Summary

Fields inherited from interface org.microbean.assign.Aggregate

EMPTY_ASSIGNMENTS, EMPTY_DEPENDENCIES

Constructor Summary

Constructors

Constructor	Description
Constant(I singleton)	Creates a new Constant.

Method Summary

Modifier and Type	Method	Description
final I	create(Creation<I> creation)	Invokes the singleton() method and returns its result.
final Optional<DynamicConstantDesc<I>>	describeConstable()	Returns an Optional containing the nominal descriptor for this instance, if one can be constructed, or an empty Optional if one cannot be constructed.
final void	destroy(I i, Destruction creation)	Destroys the supplied contextual instance.
final boolean	destroys()	Returns true if and only if the return value of an invocation of the singleton() method is AutoCloseable.
final boolean	equals(Object o)	Indicates whether some other object is "equal to" this one.
final int	hashCode()	Returns a hash code value for this object.
I	singleton()	Returns the value of the singleton record component.
final String	toString()	Returns a string representation of this record class.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.microbean.assign.Aggregate

assign, dependencies

Constructor Details

Constant

public Constant(I singleton)

Creates a new Constant.

Parameters:

singleton - an object; must not be null

Throws:

NullPointerException - if singleton is null

Method Details

create

public final I create(Creation<I> creation)

Invokes the singleton() method and returns its result.

Specified by:

create in interface Factory<I>

Parameters:

creation - a Creation; may be null; ignored

Returns:

the result of invoking the singleton() method

See Also:

• singleton()

destroys

public final boolean destroys()

Returns true if and only if the return value of an invocation of the singleton() method is AutoCloseable.

Specified by:

destroys in interface Factory<I>

Returns:

true if and only if the return value of an invocation of the singleton() method is AutoCloseable

See Also:

• Factory.destroy(Object, Destruction)

destroy

public final void destroy(I i,
 Destruction creation)

Description copied from interface: Factory

Destroys the supplied contextual instance.

The default implementation of this method closes the supplied contextual instance if it is an instance of AutoCloseable, and closes the supplied Destruction if it is non-null.

Specified by:

destroy in interface Factory<I>

Parameters:

i - the contextual instance to destroy; may be null in which case no action must be taken

creation - the object supplied to the Factory.create(Creation) method represented here as a Destruction; may be null; must have an idempotent close() method

See Also:

• Factory.create(Creation)
• Destruction
• Creation

describeConstable

public final Optional<DynamicConstantDesc<I>> describeConstable()

Description copied from interface: Factory

Returns an Optional containing the nominal descriptor for this instance, if one can be constructed, or an empty Optional if one cannot be constructed.

The default implementation of this method returns an Optional that contains a dynamic constant representing an invocation of the implementation's constructor that takes no arguments. The resolution of this dynamic constant is undefined if the implementation does not declare such a constructor.

Specified by:

describeConstable in interface Constable

Specified by:

describeConstable in interface Factory<I>

Returns:

an Optional containing the nominal descriptor for this instance, if one can be constructed, or an empty Optional if one cannot be constructed

toString

public final String toString()

Returns a string representation of this record class. The representation contains the name of the class, followed by the name and value of each of the record components.

Specified by:

toString in class Record

Returns:

a string representation of this object

hashCode

public final int hashCode()

Returns a hash code value for this object. The value is derived from the hash code of each of the record components.

Specified by:

hashCode in class Record

Returns:

a hash code value for this object

equals

public final boolean equals(Object o)

Indicates whether some other object is "equal to" this one. The objects are equal if the other object is of the same class and if all the record components are equal. All components in this record class are compared with Objects::equals(Object,Object).

Specified by:

equals in class Record

Parameters:

o - the object with which to compare

Returns:

true if this object is the same as the o argument; false otherwise.

singleton

public I singleton()

Returns the value of the singleton record component.

Specified by:

singleton in interface Factory<I>

Returns:

the value of the singleton record component