io.micronaut.context

Interface Qualifier<T>

Type Parameters:

T - The qualifier type

All Known Implementing Classes:

ClosestTypeArgumentQualifier, ConsumesMediaTypeQualifier, ProducesMediaTypeQualifier, TypeArgumentQualifier

public interface Qualifier<T>

Used to qualify which bean to select in the case of multiple possible options.

NOTE: When implementing a custom Qualifier you MUST implement Object.hashCode() and Object.equals(Object) so that the qualifier can be used in comparisons and equality checks

Since:

1.0

Author:

Graeme Rocher

Method Summary

Modifier and Type	Method and Description
default boolean	contains(Qualifier<T> qualifier) Whether this qualifier contains the given qualifier.
default <BT extends BeanType<T>> Optional<BT>	qualify(Class<T> beanType, Stream<BT> candidates) Qualify the candidate from the stream of candidates.
<BT extends BeanType<T>> Stream<BT>	reduce(Class<T> beanType, Stream<BT> candidates)

Method Detail

reduce

<BT extends BeanType<T>> Stream<BT> reduce(Class<T> beanType,
                                           Stream<BT> candidates)

Type Parameters:

BT - The bean type subclass

Parameters:

beanType - The bean type

candidates - The candidates

Returns:

The qualified candidate or null it it cannot be qualified

contains

default boolean contains(Qualifier<T> qualifier)

Whether this qualifier contains the given qualifier.

Parameters:

qualifier - The qualifier

Returns:

True it does

qualify

default <BT extends BeanType<T>> Optional<BT> qualify(Class<T> beanType,
                                                      Stream<BT> candidates)

Qualify the candidate from the stream of candidates.

Type Parameters:

BT - The bean type subclass

Parameters:

beanType - The bean type

candidates - The candidates

Returns:

The qualified candidate or Optional.empty()