001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *   http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package org.eclipse.aether.spi.locator;
020
021import java.util.List;
022
023/**
024 * A simple infrastructure to programmatically wire the various components of the repository system together when it is
025 * used outside of an IoC container. Once a concrete implementation of a service locator has been setup, clients could
026 * use
027 *
028 * <pre>
029 * RepositorySystem repoSystem = serviceLocator.getService( RepositorySystem.class );
030 * </pre>
031 *
032 * to acquire the repository system. Components that implement {@link Service} will be given an opportunity to acquire
033 * further components from the locator, thereby allowing to create the complete object graph of the repository system.
034 *
035 * @deprecated Use some out-of-the-box DI implementation instead.
036 */
037@Deprecated
038public interface ServiceLocator {
039
040    /**
041     * Gets an instance of the specified service.
042     *
043     * @param <T> The service type.
044     * @param type The interface describing the service, must not be {@code null}.
045     * @return The service instance or {@code null} if the service could not be located/initialized.
046     */
047    <T> T getService(Class<T> type);
048
049    /**
050     * Gets all available instances of the specified service.
051     *
052     * @param <T> The service type.
053     * @param type The interface describing the service, must not be {@code null}.
054     * @return The (read-only) list of available service instances, never {@code null}.
055     */
056    <T> List<T> getServices(Class<T> type);
057}