org.microbean.settings

Class Arbiter

java.lang.Object

org.microbean.settings.Arbiter

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

SourceOrderArbiter

public abstract class Arbiter
extends Object
implements Serializable

Provides value arbitration services most commonly to a Settings instance in cases where setting values would otherwise be indistinguishable from one another.

Author:

Laird Nelson

See Also:

arbitrate(Set, String, Set, Collection), Settings.arbitrate(Set, String, Set, Collection), Settings.Settings(Set, BiFunction, ConverterProvider, Iterable), Serialized Form

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Arbiter() Creates a new Arbiter.

Method Summary

Modifier and Type	Method and Description
abstract Value	arbitrate(Set<? extends Source> sources, String name, Set<? extends Annotation> qualifiers, Collection<? extends Value> values) Performs value arbitration on a Collection of Values that (normally) a Settings instance determined were indistinguishable during value acquisition, and returns the Value to be used instead (normally drawn from the Collection according to some heuristic).

Methods inherited from class java.lang.Object

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

Constructor Detail

Arbiter

protected Arbiter()

Creates a new Arbiter.

Method Detail

arbitrate

public abstract Value arbitrate(Set<? extends Source> sources,
                                String name,
                                Set<? extends Annotation> qualifiers,
                                Collection<? extends Value> values)

Performs value arbitration on a Collection of Values that (normally) a Settings instance determined were indistinguishable during value acquisition, and returns the Value to be used instead (normally drawn from the Collection according to some heuristic).

Parameters:

sources - the Set of Sources in effect during the current value acquisition operation; must not be null; must be unmodifiable; must be safe for concurrent read-only access by multiple threads

name - the name of the setting value being sought; must not be null

qualifiers - the Set of qualifier Annotations in effect during the current value acquisition operation; must not be null; must be unmodifiable; must be safe for concurrent read-only access by multiple threads

values - the Collection of Values acquired during the current value acquisition operation that were deemed to be indistinguishable; must not be null; must be unmodifiable; must be safe for concurrent read-only access by multiple threads

Returns:

the result of value arbitration as a single Value, or null if this Arbiter could not select a single Value

Throws:

NullPointerException - if any parameter value is null

ArbitrationException - if there was a procedural problem with arbitration