framework/src/main/java/org/osgi/framework/hooks/service/FindHook.java

/*
 * Copyright (c) OSGi Alliance (2008, 2013). 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.framework.hooks.service;

import java.util.Collection;
import org.osgi.annotation.versioning.ConsumerType;
import org.osgi.framework.BundleContext;
import org.osgi.framework.ServiceReference;

/**
 * OSGi Framework Service Find Hook Service.
 * 
 * <p>
 * Bundles registering this service will be called during framework service find
 * (get service references) operations.
 * 
 * @ThreadSafe
 * @author $Id: 4325a49f8c29ac9e7f32e8450db26148bbda5642 $
 */
@ConsumerType
public interface FindHook {
	/**
	 * Find hook method. This method is called during the service find operation
	 * (for example, {@link BundleContext#getServiceReferences(String, String)}
	 * ). This method can filter the result of the find operation.
	 * 
	 * @param context The bundle context of the bundle performing the find
	 *        operation.
	 * @param name The class name of the services to find or {@code null} to
	 *        find all services.
	 * @param filter The filter criteria of the services to find or {@code null}
	 *        for no filter criteria.
	 * @param allServices {@code true} if the find operation is the result of a
	 *        call to
	 *        {@link BundleContext#getAllServiceReferences(String, String)}
	 * @param references A collection of Service References to be returned as a
	 *        result of the find operation. The implementation of this method
	 *        may remove service references from the collection to prevent the
	 *        references from being returned to the bundle performing the find
	 *        operation. The collection supports all the optional
	 *        {@code Collection} operations except {@code add} and
	 *        {@code addAll}. Attempting to add to the collection will result in
	 *        an {@code UnsupportedOperationException}. The collection is not
	 *        synchronized.
	 */
	void find(BundleContext context, String name, String filter, boolean allServices, Collection<ServiceReference<?>> references);
}