org.glassfish.hk2.api.JustInTimeInjectionResolver Maven / Gradle / Ivy
Show all versions of ehcache Show documentation
/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright (c) 2012 Oracle and/or its affiliates. All rights reserved.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common Development
* and Distribution License("CDDL") (collectively, the "License"). You
* may not use this file except in compliance with the License. You can
* obtain a copy of the License at
* https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
* or packager/legal/LICENSE.txt. See the License for the specific
* language governing permissions and limitations under the License.
*
* When distributing the software, include this License Header Notice in each
* file and include the License file at packager/legal/LICENSE.txt.
*
* GPL Classpath Exception:
* Oracle designates this particular file as subject to the "Classpath"
* exception as provided by Oracle in the GPL Version 2 section of the License
* file that accompanied this code.
*
* Modifications:
* If applicable, add the following below the License Header, with the fields
* enclosed by brackets [] replaced by your own identifying information:
* "Portions Copyright [year] [name of copyright owner]"
*
* Contributor(s):
* If you wish your version of this file to be governed by only the CDDL or
* only the GPL Version 2, indicate your decision by adding "[Contributor]
* elects to include this software in this distribution under the [CDDL or GPL
* Version 2] license." If you don't indicate a single choice of license, a
* recipient has the option to distribute your version of this file under
* either the CDDL, the GPL Version 2 or to extend the choice of license to
* its licensees as provided above. However, if you add GPL Version 2 code
* and therefore, elected the GPL Version 2 license, then the option applies
* only if the new code is made subject to such option by the copyright
* holder.
*/
package org.glassfish.hk2.api;
import org.jvnet.hk2.annotations.Contract;
/**
* The JustInTimeInjectionResolver is called when an injection point
* cannot find anything to inject. It allows a third party systems
* to dynamically add descriptors to the system whenever
* an injection point would have failed to resolve (or an Optional
* injection point found no service definitions).
*
* All injection resolvers registered with the system will be called
* in a random order. Resolvers should therefore not rely on the ordering
* of installed injection resolvers. Any injection resolvers added as a
* result of this callback will NOT be called until the next injection
* resolution failure.
*
* Implementations of this interface are placed into the registry like
* any other service. One use-case would be to inject the
* {@link DynamicConfigurationService} into the implementation in order
* to add services if this resolver can do so. Another option would
* be to inject a {@link ServiceLocator} and use one of the methods
* in {@link org.glassfish.hk2.utilities.ServiceLocatorUtilities} in order
* to add services to the registry
*
* If any of the registered injection resolvers commits a dynamic change
* then the system will try one more time to resolve the injection before
* failing (or returning null if the injection point is Optional).
*
* @author jwells
*/
@Contract
public interface JustInTimeInjectionResolver {
/**
* This method will be called whenever an injection point cannot be resolved. If this
* method adds anything to the configuration it should return true. Otherwise it
* should return false. The injection point that failed to be resolved is given
* in failedInjectionPoint.
*
* If this method throws an exception that exception will be added to the set of
* exceptions in the MultiException that may be thrown from the injection resolver
*
* @param failedInjectionPoint The injection point that failed to resolve
* @return true if this method has added a descriptor to the {@link ServiceLocator}
* which may be used to resolve the {@link Injectee}. False if this method
* did not add a descriptor to the {@link ServiceLocator} that might help
* resolve the injection point
*/
public boolean justInTimeResolution(Injectee failedInjectionPoint);
}