javax.inject.Qualifier Maven / Gradle / Ivy
/*
* Copyright (C) 2009 The JSR-330 Expert Group
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package javax.inject;
import java.lang.annotation.Target;
import java.lang.annotation.Retention;
import java.lang.annotation.Documented;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
import static java.lang.annotation.ElementType.ANNOTATION_TYPE;
/**
* Identifies qualifier annotations. Anyone can define a new qualifier. A
* qualifier annotation:
*
*
* - is annotated with {@code @Qualifier}, {@code @Retention(RUNTIME)},
* and typically {@code @Documented}.
* - can have attributes.
* - may be part of the public API, much like the dependency type, but
* unlike implementation types which needn't be part of the public
* API.
* - may have restricted usage if annotated with {@code @Target}. While
* this specification covers applying qualifiers to fields and
* parameters only, some injector configurations might use qualifier
* annotations in other places (on methods or classes for example).
*
*
* For example:
*
*
* @java.lang.annotation.Documented
* @java.lang.annotation.Retention(RUNTIME)
* @javax.inject.Qualifier
* public @interface Leather {
* Color color() default Color.TAN;
* public enum Color { RED, BLACK, TAN }
* }
*
* @see javax.inject.Named @Named
*/
@Target(ANNOTATION_TYPE)
@Retention(RUNTIME)
@Documented
public @interface Qualifier {}