org.microbean.settings

Class Value

java.lang.Object

org.microbean.settings.Value

All Implemented Interfaces:

Supplier<String>

public class Value
extends Object
implements Supplier<String>

A Supplier of Strings and hence an abstraction of a (definitionally) String-typed setting value, additionally encompassing the setting name for which it is applicable and the Source whence it originated.

Author:

Laird Nelson

See Also:

Settings, Source, Source.getValue(String, Set)

Thread Safety:

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

Constructor Summary

Constructors

Constructor and Description
Value(Source source, String name, Set<Annotation> qualifiers, boolean authoritative, String value) Creates a new Value.
Value(Source source, String name, Set<Annotation> qualifiers, boolean authoritative, Supplier<? extends String> valueSupplier) Creates a new Value.
Value(Source source, String name, Set<Annotation> qualifiers, String value) Creates a new Value.
Value(Source source, String name, Set<Annotation> qualifiers, Supplier<? extends String> valueSupplier) Creates a new Value.
Value(Value other) Creates a new Value.
Value(Value other, String value) Creates a new Value.
Value(Value other, Supplier<? extends String> valueSupplier) Creates a new Value.

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object other) Returns true if the supplied Object is a Value and has a get() method implementation that returns a value equal to the return value of an invocation of this Value's get() method.
String	get() Returns the String representation of this Value.
String	getName() Returns the name of the setting for which this is a Value.
Set<Annotation>	getQualifiers() Returns a non-null, unmodifiable Set of Annotations qualifying this Value.
Source	getSource() Returns the Source that created this Value.
int	hashCode() Returns a hashcode for this Value based off the return value of the get() method and nothing else.
boolean	isAuthoritative() Returns true if this Value is to be treated as coming from an authoritative source.
String	toString() Returns a String representation of this Value as of the current moment by returning the result of invoking the get() method.

Methods inherited from class java.lang.Object

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

Constructor Detail

Value

public Value(Value other)

Creates a new Value.

Parameters:

other - the Value to copy; must not be null

Throws:

NullPointerException - if other is null

Value

public Value(Value other,
             String value)

Creates a new Value.

Parameters:

other - the Value to copy; must not be null

value - the String to be returned by the get() method; may be null

Throws:

NullPointerException - if other is null

Value

public Value(Value other,
             Supplier<? extends String> valueSupplier)

Creates a new Value.

Parameters:

other - the Value to copy; must not be null

valueSupplier - a Supplier of Strings whose Supplier.get() method will be called by this Value's get() method; may be null; if non-null, must be safe for concurrent access by multiple threads

Throws:

NullPointerException - if other is null

Value

public Value(Source source,
             String name,
             Set<Annotation> qualifiers,
             String value)

Creates a new Value.

Parameters:

source - the Source that created this Value; may be null to indicate that the Value was synthesized

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

qualifiers - a Set of Annotations qualifying this Value; may be null; will be iterated over by this constructor without any extra synchronization; will be copied shallowly by this constructor if it is non-null

value - the String to be returned by the get() method; may be null

Throws:

NullPointerException - if name is null

Value

public Value(Source source,
             String name,
             Set<Annotation> qualifiers,
             Supplier<? extends String> valueSupplier)

Creates a new Value.

Parameters:

source - the Source that created this Value; may be null to indicate that the Value was synthesized

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

qualifiers - a Set of Annotations qualifying this Value; may be null; will be iterated over by this constructor without any extra synchronization; will be copied shallowly by this constructor if it is non-null

valueSupplier - a Supplier of Strings whose Supplier.get() method will be called by this Value's get() method; may be null; if non-null, must be safe for concurrent access by multiple threads

Throws:

NullPointerException - if name is null

Value

public Value(Source source,
             String name,
             Set<Annotation> qualifiers,
             boolean authoritative,
             String value)

Creates a new Value.

Parameters:

source - the Source that created this Value; may be null to indicate that the Value was synthesized

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

qualifiers - a Set of Annotations qualifying this Value; may be null; will be iterated over by this constructor without any extra synchronization; will be copied shallowly by this constructor if it is non-null

authoritative - whether this Value is to be treated as coming from an authoritative source

value - the String to be returned by the get() method; may be null

Throws:

NullPointerException - if name is null

Value

public Value(Source source,
             String name,
             Set<Annotation> qualifiers,
             boolean authoritative,
             Supplier<? extends String> valueSupplier)

Creates a new Value.

Parameters:

source - the Source that created this Value; may be null to indicate that the Value was synthesized

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

qualifiers - a Set of Annotations qualifying this Value; may be null; will be iterated over by this constructor without any extra synchronization; will be copied shallowly by this constructor if it is non-null

authoritative - whether this Value is to be treated as coming from an authoritative source

valueSupplier - a Supplier of Strings whose Supplier.get() method will be called by this Value's get() method; may be null; if non-null, must be safe for concurrent access by multiple threads

Throws:

NullPointerException - if name is null

Method Detail

get

public final String get()

Returns the String representation of this Value.

Specified by:

get in interface Supplier<String>

Returns:

the String representation of this Value, which may be null

Idempotency:

No guarantees are made with respect to the idempotency of this method.

Nullability:

This method may return null.

Thread Safety:

This method is safe for concurrent use by multiple threads.

isAuthoritative

public final boolean isAuthoritative()

Returns true if this Value is to be treated as coming from an authoritative source.

Returns:

true if this Value is to be treated as coming from an authoritative source; false otherwise

Idempotency:

This method is idempotent.

Thread Safety:

This method is safe for concurrent use by multiple threads.

getSource

public final Source getSource()

Returns the Source that created this Value.

Returns:

the Source that created this Value, which may be null

Idempotency:

This method is idempotent.

Nullability:

This method may return null.

Thread Safety:

This method is safe for concurrent use by multiple threads.

getName

public final String getName()

Returns the name of the setting for which this is a Value.

Returns:

the name of the setting for which this is a Value; never null

Idempotency:

This method is idempotent.

Nullability:

This method never returns null.

Thread Safety:

This method is safe for concurrent use by multiple threads.

getQualifiers

public final Set<Annotation> getQualifiers()

Returns a non-null, unmodifiable Set of Annotations qualifying this Value.

Returns:

a non-null, unmodifiable Set of Annotations qualifying this Value

Idempotency:

This method is idempotent.

Nullability:

This method never returns null.

Thread Safety:

This method is safe for concurrent use by multiple threads.

hashCode

public int hashCode()

Returns a hashcode for this Value based off the return value of the get() method and nothing else.

Note that because the return value of invocations of a Value's get() method can change over time, in general Value hashcodes should be treated with great care.

Overrides:

hashCode in class Object

Returns:

a hashcode for this Value

See Also:

equals(Object)

Idempotency:

No guarantees are made with respect to the idempotency of this method.

Thread Safety:

This method is and overrides must be safe for concurrent use by multiple threads.

equals

public boolean equals(Object other)

Returns true if the supplied Object is a Value and has a get() method implementation that returns a value equal to the return value of an invocation of this Value's get() method.

Note that because the return value of invocations of a Value's get() method can change over time, in general Value equality comparisons should be treated with great care.

Overrides:

equals in class Object

Parameters:

other - the Object to compare; may be null

Returns:

true if the supplied Object is a Value and has a get() method implementation that returns a value equal to the return value of an invocation of this Value's get() method; false otherwise

See Also:

hashCode()

Idempotency:

No guarantees are made with respect to the idempotency of this method.

Thread Safety:

This method is and overrides must be safe for concurrent use by multiple threads.

toString

public String toString()

Returns a String representation of this Value as of the current moment by returning the result of invoking the get() method.

This method may return null.

Overrides:

toString in class Object

Returns:

a String representation of this Value as of the current moment, or null

See Also:

get()

Idempotency:

No guarantees are made with respect to the idempotency of this method.

Nullability:

This method and its overrides may return null.

Thread Safety:

This method is and its overrides must be safe for concurrent use by multiple threads.