alexh.weak

Interface Weak<Self extends Weak<Self>>

All Known Subinterfaces:

Dynamic

All Known Implementing Classes:

AbstractDynamic, XmlDynamic

public interface Weak<Self extends Weak<Self>>

Wrapper for a weakly typed object or absence, providing casting, presence gathering & conversion methods

Author:

Alex Butler

Method Summary

Modifier and Type	Method and Description
default <T> T	as(Class<T> type) As asObject() casting to input type
default <T> List<T>	asList() Shortcut for as(List.class), with malleable generic type
default <K,V> Map<K,V>	asMap() Shortcut for as(Map.class), with malleable generic type
Object	asObject() Returns inner value implicitly asserting that the value is not absent, ie isPresent() is true
default Optional<Object>	asOptional() Converts this value/absence wrapper into a standard optional
default String	asString() Shortcut for as(String.class)
default Converter	convert() Shortcut for wrapping asObject() in a Converter instance
default boolean	is(Class<?> type)
default boolean	isList() Shortcut for is(List.class)
default boolean	isMap() Shortcut for is(Map.class)
boolean	isPresent() Returns if this instance wraps a non-null value.
default boolean	isString() Shortcut for is(String.class)
default OptionalWeak<Self>	maybe() Returns an optional wrapping of this instance, with resultant Optional.isPresent() return consistent with isPresent()

Method Detail

isPresent

boolean isPresent()

Returns if this instance wraps a non-null value. True implies asObject() will not throw

Returns:

if this instance wraps a non-null value

asObject

Object asObject()

Returns inner value implicitly asserting that the value is not absent, ie isPresent() is true

Returns:

unwrapped inner value

Throws:

NoSuchElementException - absent

asOptional

default Optional<Object> asOptional()

Converts this value/absence wrapper into a standard optional

Returns:

optional with consistent Optional.isPresent() to isPresent()

as

default <T> T as(Class<T> type)

As asObject() casting to input type

Type Parameters:

T - cast type

Parameters:

type - cast type

Returns:

unwrapped inner value cast to input type

Throws:

ClassCastException - when the wrapped instance that cannot be cast to the input

NoSuchElementException - absent

asString

default String asString()

Shortcut for as(String.class)

See Also:

as(Class)

asList

default <T> List<T> asList()

Shortcut for as(List.class), with malleable generic type

See Also:

as(Class)

asMap

default <K,V> Map<K,V> asMap()

Shortcut for as(Map.class), with malleable generic type

See Also:

as(Class)

is

default boolean is(Class<?> type)

Parameters:

type - type to test inner value with

Returns:

value is present and an instance of input type

isMap

default boolean isMap()

Shortcut for is(Map.class)

See Also:

is(Class)

isString

default boolean isString()

Shortcut for is(String.class)

See Also:

is(Class)

isList

default boolean isList()

Shortcut for is(List.class)

See Also:

is(Class)

convert

default Converter convert()

Shortcut for wrapping asObject() in a Converter instance

Returns:

Converter instance for inner value

Throws:

NoSuchElementException - absent

See Also:

Converter.convert(Object)

maybe

default OptionalWeak<Self> maybe()

Returns an optional wrapping of this instance, with resultant Optional.isPresent() return consistent with isPresent()

Returns:

optional wrapping of this, or empty if this is absent