org.microbean.configuration.spi

Class ConfigurationValueSourceComparingArbiter

java.lang.Object

org.microbean.configuration.spi.ComparatorBasedArbiter<ConfigurationValue>

org.microbean.configuration.spi.ConfigurationValueSourceComparingArbiter

All Implemented Interfaces:

Arbiter

Direct Known Subclasses:

SystemPropertiesOutrankEnvironmentVariablesArbiter

public class ConfigurationValueSourceComparingArbiter
extends ComparatorBasedArbiter<ConfigurationValue>

A ComparatorBasedArbiter that compares ConfigurationValues by their sources.

Author:

Laird Nelson

See Also:

ConfigurationValue, ComparatorBasedArbiter

Constructor Summary

Constructors

Constructor and Description
ConfigurationValueSourceComparingArbiter() Creates a new ConfigurationValueSourceComparingArbiter.
ConfigurationValueSourceComparingArbiter(List<? extends Configuration> configurationInstances) Creates a new ConfigurationValueSourceComparingArbiter.

Method Summary

Modifier and Type	Method and Description
ConfigurationValue	arbitrate(Map<? extends String,? extends String> requestedCoordinates, String name, Collection<? extends ConfigurationValue> ambiguousValues) Resolves the configuration value ambiguity represented by the supplied ambiguousValues parameter value by selecting the ConfigurationValue whose associated source is ranked closer to 0.
protected boolean	canArbitrate(Collection<? extends ConfigurationValue> ambiguousValues) Returns true if this ConfigurationValueSourceComparingArbiter can effectively arbitrate the conflict represented by the supplied Collection of ambiguous ConfigurationValues.
protected RankedComparator<ConfigurationValue>	getComparator() Returns the RankedComparator used by this ConfigurationValueSourceComparingArbiter implementation.

Methods inherited from class java.lang.Object

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

Constructor Detail

ConfigurationValueSourceComparingArbiter

public ConfigurationValueSourceComparingArbiter()

Creates a new ConfigurationValueSourceComparingArbiter.

See Also:

ConfigurationValueSourceComparingArbiter(List)

ConfigurationValueSourceComparingArbiter

public ConfigurationValueSourceComparingArbiter(List<? extends Configuration> configurationInstances)

Creates a new ConfigurationValueSourceComparingArbiter.

Parameters:

configurationInstances - a List of Class instances describing configuration value sources; may be (trivially) null

See Also:

RankedComparator.RankedComparator(List)

Method Detail

arbitrate

public ConfigurationValue arbitrate(Map<? extends String,? extends String> requestedCoordinates,
                                    String name,
                                    Collection<? extends ConfigurationValue> ambiguousValues)

Resolves the configuration value ambiguity represented by the supplied ambiguousValues parameter value by selecting the ConfigurationValue whose associated source is ranked closer to 0.

Parameters:

requestedCoordinates - the (immutable) configuration coordinates in effect for the request; may be null

name - the name of the configuration value; must not be null

ambiguousValues - an immutable Collection of definitionally ambiguous ConfigurationValues that resulted from the request; may be null

Returns:

the result of arbitration, or null if the dispute cannot be arbitrated by this Arbiter

Throws:

NullPointerException - if name is null

getComparator

protected RankedComparator<ConfigurationValue> getComparator()

Returns the RankedComparator used by this ConfigurationValueSourceComparingArbiter implementation.

This method never returns null.

Overrides of this method must never return null.

Overrides:

getComparator in class ComparatorBasedArbiter<ConfigurationValue>

Returns:

a non-null RankedComparator

See Also:

ComparatorBasedArbiter.ComparatorBasedArbiter(Comparator)

canArbitrate

protected boolean canArbitrate(Collection<? extends ConfigurationValue> ambiguousValues)

Returns true if this ConfigurationValueSourceComparingArbiter can effectively arbitrate the conflict represented by the supplied Collection of ambiguous ConfigurationValues.

Parameters:

ambiguousValues - a Collection of ConfigurationValues; may be null; must not be modified by overrides of this method

Returns:

true if this ConfigurationValueSourceComparingArbiter can effectively arbitrate the conflict represented by the supplied Collection of ambiguous ConfigurationValues; false otherwise