org.glassfish.hk2.api.Injectee Maven / Gradle / Ivy
/*
* Copyright (c) 2012, 2018 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0, which is available at
* http://www.eclipse.org/legal/epl-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception, which is available at
* https://www.gnu.org/software/classpath/license.html.
*
* SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
*/
package org.glassfish.hk2.api;
import java.lang.annotation.Annotation;
import java.lang.reflect.AnnotatedElement;
import java.lang.reflect.Type;
import java.util.Set;
/**
* An Injectee represents the point of injection. It can be used
* by injection resolvers to discover all of the information available about
* the entity being injected into.
*
* @author jwells
*/
public interface Injectee {
/**
* This is the required type of the injectee. The object
* that is injected into this point must be type-safe
* with regards to this type
*
* @return The type that this injectee is expecting. Any object
* injected into this injection point must be type-safe with
* regards to this type
*/
public Type getRequiredType();
/**
* This is the set of required qualifiers for this injectee. All
* of these qualifiers must be present on the implementation class
* of the object that is injected into this injectee. Note that the
* fields of the annotation must also match
*
* @return Will not return null, but may return an empty set. The
* set of all qualifiers that must match.
*/
public Set getRequiredQualifiers();
/**
* If this Injectee is a constructor or method parameter, this will
* return the index of the parameter. If this Injectee is a field,
* this will return -1
*
* @return the position of the parameter, or -1 if this is a field
*/
public int getPosition();
/**
* Returns the parent class for this injectee. This is the
* class of the object that will be injected into. This
* field may return null if this is from a service lookup
*
* @return The class of the object that will be injected into
*/
public Class getInjecteeClass();
/**
* If this Injectee is in a constructor this will return the
* constructor being injected into. If this Injectee is in a
* method this will return the method being injected into. If this
* injectee represents a field, this will return the field being
* injected into. This injectee may be neither in which case this
* will return null
*
* @return The parent of the injectee, which may be null
*/
public AnnotatedElement getParent();
/**
* This method returns true if this injection point is annotated
* with VOptional. In this case if there is no definition for
* the injection point in the system it is allowable for the system
* to merely return null
*
* @return true if the injection point is annotated with VOptional,
* false otherwise
*/
public boolean isOptional();
/**
* This method returns true if this injection point is annotated
* with VSelf. In this case the required type must have
* a raw class of {@link ActiveDescriptor}, isOptional must be
* false and the set of required qualifiers must be empty
*
* @return true if the injection point is annotated with VSelf,
* false otherwise
*/
public boolean isSelf();
/**
* This method returns the {@link Unqualified} annotation if it is present
* on the injection point. This can be used to determine what qualifiers
* should NOT be given to the injection point.
*
* @return The {@link Unqualified} annotation on the injection point, or null
* if there is no {@link Unqualified} annotation on the injection point
*/
public Unqualified getUnqualified();
/**
* This returns the ActiveDescriptor of the injectee
* if it is known
*
* @return The ActiveDescriptor of the injectee,
* or null if the parent is not known
*/
public ActiveDescriptor getInjecteeDescriptor();
}