001/*
002 * ====================================================================
003 * Licensed to the Apache Software Foundation (ASF) under one
004 * or more contributor license agreements.  See the NOTICE file
005 * distributed with this work for additional information
006 * regarding copyright ownership.  The ASF licenses this file
007 * to you under the Apache License, Version 2.0 (the
008 * "License"); you may not use this file except in compliance
009 * with the License.  You may obtain a copy of the License at
010 *
011 *   http://www.apache.org/licenses/LICENSE-2.0
012 *
013 * Unless required by applicable law or agreed to in writing,
014 * software distributed under the License is distributed on an
015 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
016 * KIND, either express or implied.  See the License for the
017 * specific language governing permissions and limitations
018 * under the License.
019 * ====================================================================
020 *
021 * This software consists of voluntary contributions made by many
022 * individuals on behalf of the Apache Software Foundation.  For more
023 * information on the Apache Software Foundation, please see
024 * <http://www.apache.org/>.
025 *
026 */
027
028package org.apache.http.config;
029
030import org.apache.http.annotation.ThreadingBehavior;
031import org.apache.http.annotation.Contract;
032
033import java.util.Locale;
034import java.util.Map;
035import java.util.concurrent.ConcurrentHashMap;
036
037/**
038 * Generic registry of items keyed by low-case string ID.
039 *
040 * @since 4.3
041 */
042@Contract(threading = ThreadingBehavior.SAFE)
043public final class Registry<I> implements Lookup<I> {
044
045    private final Map<String, I> map;
046
047    Registry(final Map<String, I> map) {
048        super();
049        this.map = new ConcurrentHashMap<String, I>(map);
050    }
051
052    @Override
053    public I lookup(final String key) {
054        if (key == null) {
055            return null;
056        }
057        return map.get(key.toLowerCase(Locale.ROOT));
058    }
059
060    @Override
061    public String toString() {
062        return map.toString();
063    }
064
065}