Class Beans

java.lang.Object

org.microbean.bean.Beans

All Implemented Interfaces:

Reducible<AttributedType,Bean<?>>, Selectable<AttributedType,Bean<?>>

public final class Beans
extends Object
implements Selectable<AttributedType,Bean<?>>, Reducible<AttributedType,Bean<?>>

A Selectable and Reducible implementation that works with Bean and AttributedType instances.

Author:

Laird Nelson

See Also:

• Beans(Selectable, Reducible)
• Selectable
• Reducible
• Reducer
• RankedReducer
• Bean
• AttributedType

Constructor Summary

Constructors

Constructor	Description
Beans(Selectable<AttributedType,Bean<?>> s)	Creates a new Beans.
Beans(Selectable<AttributedType,Bean<?>> s, Reducible<AttributedType,Bean<?>> r)	Creates a new Beans.

Method Summary

Modifier and Type	Method	Description
static final Selectable<AttributedType,Bean<?>>	cachingSelectableOf(Matcher<? super AttributedType,? super Id> idMatcher, Map<? extends AttributedType,? extends List<Bean<?>>> selections, Collection<? extends Bean<?>> beans)	Returns a new Selectable that caches its results.
final Bean<?>	reduce(AttributedType c)	Given a criteria object, which may be null, returns an object that represents the reduction of a notional collection of objects.
final List<Bean<?>>	select(AttributedType c)	Selects and returns an immutable List representing a sublist of this Selectable's elements, as mediated by the supplied criteria.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.microbean.bean.Selectable

list

Constructor Details

Beans

public Beans(Selectable<AttributedType,Bean<?>> s)

Creates a new Beans.

Bean instances selected by the supplied Selectable will be reduced using a RankedReducer.

Parameters:

s - a Selectable; must not be null

See Also:

• RankedReducer

Beans

public Beans(Selectable<AttributedType,Bean<?>> s,
 Reducible<AttributedType,Bean<?>> r)

Creates a new Beans.

Parameters:

s - a Selectable; must not be null

r - a Reducible to apply to elements selected by the supplied Selectable; must not be null

See Also:

• cachingSelectableOf(Matcher, Map, Collection)
• Reducible.of(Selectable, Reducer)
• RankedReducer

Method Details

select

public final List<Bean<?>> select(AttributedType c)

Description copied from interface: Selectable

Selects and returns an immutable List representing a sublist of this Selectable's elements, as mediated by the supplied criteria.

Implementations of this method must be idempotent and must return a determinate value.

Implementations of this method must not return null.

Implementations of this method should not call Selectable.list(), since that method is typically implemented in terms of this one.

Specified by:

select in interface Selectable<AttributedType,Bean<?>>

Parameters:

c - the criteria to use; may be null

Returns:

an immutable sublist of this Selectable's elements; never null

See Also:

• Selectable.list()

reduce

public final Bean<?> reduce(AttributedType c)

Description copied from interface: Reducible

Given a criteria object, which may be null, returns an object that represents the reduction of a notional collection of objects.

Most Reducible implementations will return determine values from invocations of this method, but there is no requirement to do so.

Specified by:

reduce in interface Reducible<AttributedType,Bean<?>>

Parameters:

c - the criteria; may be null to indicate no criteria

Returns:

a single object, or null

cachingSelectableOf

public static final Selectable<AttributedType,Bean<?>> cachingSelectableOf(Matcher<? super AttributedType,? super Id> idMatcher,
 Map<? extends AttributedType,? extends List<Bean<?>>> selections,
 Collection<? extends Bean<?>> beans)

Returns a new Selectable that caches its results.

The cache is unbounded.

Parameters:

idMatcher - an IdMatcher; must not be null

selections - a (normally empty) Map of precomputed selections; must not be null

beans - a Collection of Beans; must not be null

Returns:

a new Selectable; never null

Throws:

NullPointerException - if any argument is null