/*
 * Copyright (c) 2017, 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.jersey.internal.inject;

import java.lang.annotation.Annotation;

This class allows users to provide a custom injection target for any annotation (including @Inject). The user would usually only provide a resolver for @Inject if it were specializing the system provided resolver for @Inject. Otherwise, this resolver can be used to provide injection points for any annotation. 
 Jersey provides all InjectionResolvers for JAX-RS annotation and org.glassfish.jersey.server.Uri apart from Context which must be implemented and registered directly as a part of DI integration because of many optimization which cannot be implemented on Jersey side. 
 The InjectionResolvers are delivered to DI integration using InjectionManager.register(Binder) and DI provider just filter InjectionResolverBinding and internally register the annotation handling using its own mechanism. 
Type parameters:
<T> – This must be the annotation class of the injection annotation that this resolver will handle./**
 * This class allows users to provide a custom injection target for any annotation (including {@code &#64;Inject}). The user would
 * usually only provide a resolver for {@code &#64;Inject} if it were specializing the system provided resolver for
 * {@code &#64;Inject}. Otherwise, this resolver can be used to provide injection points for any annotation.
 * <p>
 * Jersey provides all {@code InjectionResolvers} for JAX-RS annotation and {@code org.glassfish.jersey.server.Uri} apart from
 * {@link javax.ws.rs.core.Context} which must be implemented and registered directly as a part of DI integration because of
 * many optimization which cannot be implemented on Jersey side.
 * <p>
 * The {@code InjectionResolvers} are delivered to DI integration using {@link InjectionManager#register(Binder)} and DI provider
 * just filter {@link InjectionResolverBinding} and internally register the annotation handling using its own mechanism.
 *
 * @param <T> This must be the annotation class of the injection annotation that this resolver will handle.
 */
public interface InjectionResolver<T extends Annotation> {

    
This method will return the object that should be injected into the given injection point.  It is the responsibility of the
implementation to ensure that the object returned can be safely injected into the injection point.

This method should not do the injection themselves.
Params:
injectee – The injection point this value is being injected into
Returns:
A possibly null value to be injected into the given injection point/**
     * This method will return the object that should be injected into the given injection point.  It is the responsibility of the
     * implementation to ensure that the object returned can be safely injected into the injection point.
     * <p>
     * This method should not do the injection themselves.
     *
     * @param injectee The injection point this value is being injected into
     * @return A possibly null value to be injected into the given injection point
     */
    Object resolve(Injectee injectee);

    
This method should return true if the annotation that indicates that this is an injection point can appear in the parameter
list of a constructor.
Returns:
true if the injection annotation can appear in the parameter list of a constructor./**
     * This method should return true if the annotation that indicates that this is an injection point can appear in the parameter
     * list of a constructor.
     *
     * @return true if the injection annotation can appear in the parameter list of a constructor.
     */
    boolean isConstructorParameterIndicator();

    
This method should return true if the annotation that indicates that this is an injection point can appear in the parameter
list of a method.
Returns:
true if the injection annotation can appear in the parameter list of a method./**
     * This method should return true if the annotation that indicates that this is an injection point can appear in the parameter
     * list of a method.
     *
     * @return true if the injection annotation can appear in the parameter list of a method.
     */
    boolean isMethodParameterIndicator();

    
This method returns the annotation for what the injection resolver is implemented.
Returns:
handled annotation by injection resolver./**
     * This method returns the annotation for what the injection resolver is implemented.
     *
     * @return handled annotation by injection resolver.
     */
    Class<T> getAnnotation();

}