org.microbean.settings

Class Source

java.lang.Object

org.microbean.settings.Source

Direct Known Subclasses:

EnvironmentVariablesSource, Settings, SystemPropertiesSource

public abstract class Source
extends Object

An abstraction of a source of String-typed configuration values.

Source instances are used most commonly by Settings instances, which layer conversion and arbitration atop them.

Author:

Laird Nelson

See Also:

getValue(String, Set), Value, Settings, Settings.get(String, Set, Class, BiFunction)

Thread Safety:

Instances of this class must be safe for concurrent use by multiple threads.

Constructor Summary

Constructors

Constructor and Description
Source()

Method Summary

Modifier and Type	Method and Description
abstract Value	getValue(String name, Set<Annotation> qualifiers) Creates or otherwise acquires and returns a Value for the supplied name and Set of qualifiers.

Methods inherited from class java.lang.Object

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

Constructor Detail

Source

public Source()

Method Detail

getValue

public abstract Value getValue(String name,
                               Set<Annotation> qualifiers)

Creates or otherwise acquires and returns a Value for the supplied name and Set of qualifiers.

Parameters:

name - the name of the setting for which a Value is to be returned; must not be null

qualifiers - a Set of qualifier Annotation instances; may be null

Returns:

a suitable Value, or null if no Value could be created or acquired

Throws:

NullPointerException - if name is null

ValueAcquisitionException - if there was a procedural problem acquiring a Value

Idempotency:

An implementation of this method need not be idempotent. That is, two invocations supplied with the same name and qualifiers parameter values may or may not return Values that are identical, equal or neither.

Nullability:

Implementations of this method are permitted to return null.

Thread Safety:

Implementations of this method must be safe for concurrent use by multiple threads.