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