Interface ConfigValue<T>

Type Parameters:

T - type of the value

All Superinterfaces:

OptionalValue<T>, Value<T>

public interface ConfigValue<T>
extends OptionalValue<T>

A typed value of a Config node.

You can use accessor methods on Config to obtain this value, such as Config.as(Class). It provides Optional-style access to the value. In addition it has methods to access config values as supplier().

See Also:

• Config.as(Class)
• Config.as(Function)
• Config.as(io.helidon.common.GenericType)

Method Summary

Modifier and Type	Method	Description
<N> ConfigValue<N>	as(Function<? super T, ? extends N> mapper)	Convert this ConfigValue to a different type using a mapper function.
default T	get()	Typed value of the represented Config node.
Config.Key	key()	Returns the fully-qualified key of the originating Config node.
default String	name()	Returns the last token of the fully-qualified key for the originating Config node.
Supplier<Optional<T>>	optionalSupplier()	Returns a Supplier of an Optional<T> of the configuration node.
Supplier<T>	supplier()	Returns a supplier of a typed value.
Supplier<T>	supplier(T defaultValue)	Returns a supplier of a typed value with a default.

Methods inherited from interface OptionalValue

as, as, asBoolean, asDouble, asInt, asLong, asString, ifPresent, ifPresentOrElse, isEmpty, isPresent, map, or, orElse, orElseGet, orElseThrow, orElseThrow

Modifier and Type	Method	Description
<N> OptionalValue<N>	as(GenericType<N> type)	Convert this value to a different type using a mapper.
<N> OptionalValue<N>	as(Class<N> type)	Convert this value to a different type using a mapper.
default OptionalValue<Boolean>	asBoolean()	Boolean typed value.
default OptionalValue<Double>	asDouble()	Double typed value.
default OptionalValue<Integer>	asInt()	Integer typed value.
default OptionalValue<Long>	asLong()	Long typed value.
default OptionalValue<String>	asString()	String typed value.
default void	ifPresent(Consumer<? super T> consumer)	If a value is present, invoke the specified consumer with the value, otherwise do nothing.
default void	ifPresentOrElse(Consumer<T> action, Runnable emptyAction)	If a value is present, performs the given action with the value, otherwise performs the given empty-based action.
default boolean	isEmpty()	Return false if there is a value present, otherwise true.
default boolean	isPresent()	Return true if there is a value present, otherwise false.
default <U> Optional<U>	map(Function<? super T, ? extends U> mapper)	If a value is present, apply the provided mapping function to it, and if the result is non-null, return an Optional describing the result.
default Optional<T>	or(Supplier<? extends Optional<T>> supplier)	If the underlying Optional does not have a value, set it to the Optional produced by the supplying function.
default T	orElse(T other)	Return the value if present, otherwise return other.
default T	orElseGet(Supplier<? extends T> other)	Return the value if present, otherwise invoke other and return the result of that invocation.
default T	orElseThrow()	If a value is present, returns the value, otherwise throws NoSuchElementException.
default <X extends Throwable> T	orElseThrow(Supplier<? extends X> exceptionSupplier)	Return the contained value, if present, otherwise throw an exception to be created by the provided supplier.

Methods inherited from interface Value

asOptional, filter, flatMap, get, get, getBoolean, getDouble, getInt, getLong, getString, stream

Modifier and Type	Method	Description
Optional<T>	asOptional()	Typed value as Optional.
default Optional<T>	filter(Predicate<? super T> predicate)	If a value is present, and the value matches the given predicate, return an Optional describing the value, otherwise return an empty Optional.
default <U> Optional<U>	flatMap(Function<? super T, Optional<? extends U>> mapper)	Apply the provided Optional-bearing mapping function to this value, return that result.
default <N> N	get(GenericType<N> type)	Convert this value to a different type using a mapper.
default <N> N	get(Class<N> type)	Convert this value to a different type using a mapper.
default boolean	getBoolean()	Boolean typed value.
default double	getDouble()	Double typed value.
default int	getInt()	Integer typed value.
default long	getLong()	Long typed value.
default String	getString()	String typed value.
default Stream<T>	stream()	If a value is present, returns a sequential Stream containing only that value, otherwise returns an empty Stream.

Method Details

key

Config.Key key()

Returns the fully-qualified key of the originating Config node.

The fully-qualified key is a sequence of tokens derived from the name of each node along the path from the config root to the current node. Tokens are separated by . (the dot character). See name() for more information on the format of each token.

Returns:

current config node key

See Also:

• name()

name

default String name()

Returns the last token of the fully-qualified key for the originating Config node.

The name of a node is the last token in its fully-qualified key.

The exact format of the name depends on the Type of the containing node:

• from a Config.Type.OBJECT node the token for a child is the name of the object member;
• from a Config.Type.LIST node the token for a child is a zero-based index of the element, an unsigned base-10 integer value with no leading zeros.

The ABNF syntax of config key is:

config-key = *1( key-token *( "." key-token ) )
 key-token = *( unescaped / escaped )
 unescaped = %x00-2D / %x2F-7D / %x7F-10FFFF
           ; %x2E ('.') and %x7E ('~') are excluded from 'unescaped'
   escaped = "~" ( "0" / "1" )
           ; representing '~' and '.', respectively

Specified by:

name in interface Value<T>

Returns:

current config node key

See Also:

• key()
• Config.Key.name()

get

default T get()
       throws MissingValueException,
ConfigMappingException

Typed value of the represented Config node. Throws MissingValueException if the node is Config.Type.MISSING type.

Specified by:

get in interface OptionalValue<T>

Specified by:

get in interface Value<T>

Returns:

direct value of this node converted to the expected type

Throws:

MissingValueException - in case the node is Config.Type.MISSING.

ConfigMappingException - in case the value cannot be converted to the expected type

as

<N> ConfigValue<N> as(Function<? super T, ? extends N> mapper)

Convert this ConfigValue to a different type using a mapper function.

Specified by:

as in interface OptionalValue<T>

Specified by:

as in interface Value<T>

Type Parameters:

N - type of the returned ConfigValue

Parameters:

mapper - mapper to map the type of this ConfigValue to a type of the returned ConfigValue

Returns:

a new value with the new type

supplier

Supplier<T> supplier()

Returns a supplier of a typed value. The value provided from the supplier is the latest value available. E.g. in case there is a file config source that is being watched and a value is changed, this supplier would return the latest value, whereas get() would return the original value.

Note that Supplier.get() can throw a ConfigMappingException or MissingValueException as the get() method.

Returns:

a supplier of a typed value

supplier

Supplier<T> supplier(T defaultValue)

Returns a supplier of a typed value with a default. The value provided from the supplier is the latest value available. E.g. in case there is a file config source that is being watched and a value is changed, this supplier would return the latest value, whereas OptionalValue.orElse(Object) would return the original value.

Note that Supplier.get() can throw a ConfigMappingException as the OptionalValue.orElse(Object) method.

Parameters:

defaultValue - a value to be returned if the supplied value represents a Config node that has no direct value

Returns:

a supplier of a typed value

optionalSupplier

Supplier<Optional<T>> optionalSupplier()

Returns a Supplier of an Optional<T> of the configuration node. Supplier returns a empty if the node does not have a direct value.

Returns:

a supplier of the value as an Optional typed instance, empty in case the node does not have a direct value

See Also:

• Value.asOptional()
• supplier()