org.osgi.annotation.bundle.Directive Maven / Gradle / Ivy
/*
* Copyright (c) OSGi Alliance (2016, 2018). All Rights Reserved.
*
* 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 org.osgi.annotation.bundle;
import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
* Mark an annotation element as a directive.
*
* This is used when applying {@link Capability} or {@link Requirement} as a
* meta annotation to an annotation declaration. The value of the annotation
* element annotated with {@code Directive} is used as the value of a directive
* in the generated capability or requirement clause. For example:
*
*
* @Capability(namespace = "my.namespace")
* public @interface MyCapability {
* @Directive("resource")
* String value() default "";
* }
*
* @MyCapability("foo")
* public MyClass {}
*
*
* The use of the {@code MyCapability} annotation, which is meta annotated with
* the {@code Capability} and {@code Directive} annotations, will result in a
* capability in the namespace {@code my.namespace} with the directive
* {@code resource:=foo}.
*
* If the element annotated with {@code Directive} is unspecified when applied,
* then the directive must not be generated in the generated capability or
* requirement clause. For example:
*
*
* @MyCapability
* public MyClass {}
*
*
* will not have the {@code resource} directive in the generated capability.
*
* This annotation is not retained at runtime. It is for use by tools to
* generate bundle manifests.
*
* @author $Id: b0e9776264d7c1598147b7c9826e92e7224aae35 $
*/
@Documented
@Retention(RetentionPolicy.CLASS)
@Target(ElementType.METHOD)
public @interface Directive {
/**
* The name of the directive.
*
* If not specified, the name of the annotated element is used as the name
* of the directive.
*/
String value() default "";
}