org.oasisopen.sca.annotation.Reference Maven / Gradle / Ivy
/*
* Copyright(C) OASIS(R) 2005,2010. All Rights Reserved.
* OASIS trademark, IPR and other policies apply.
*/
package org.oasisopen.sca.annotation;
import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.ElementType.PARAMETER;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;
/**
* The @Reference annotation type is used to annotate a Java class field,
* a setter method, or a constructor parameter that is used to inject a
* service that resolves the reference. The interface of the service
* injected is defined by the type of the Java class field or the type
* of the input parameter of the setter method or constructor.
*
* The @Reference annotation MUST NOT be used on a class field that is
* declared as final.
*
* References can also be injected via setter methods even when
* the @Reference annotation is not present. However, the @Reference
* annotation must be used in order to inject a reference onto a non-public
* field. In the case where there is no @Reference annotation, the name
* of the reference is the same as the name of the field or setter.
*
* Where there is both a setter method and a field for a reference, the
* setter method is used.
*/
@Target({METHOD, FIELD, PARAMETER})
@Retention(RUNTIME)
public @interface Reference {
/**
* The name of the reference. For a field annotation, the default is
* the name of the field of the Java class. For a setter method
* annotation, the default is the JavaBeans property name corresponding
* to the setter method name. For a constructor parameter annotation,
* there is no default and the name attribute MUST be present.
*
* @return the name of the reference
*/
String name() default "";
/**
* Specifies whether injection of service or services is required.
* Defaults to true. For a constructor parameter annotation, this
* attribute MUST have the value true.
*
* @return true if injection is required
*/
boolean required() default true;
}