001    /*
002     *  Copyright 2001-2009 Stephen Colebourne
003     *
004     *  Licensed under the Apache License, Version 2.0 (the "License");
005     *  you may not use this file except in compliance with the License.
006     *  You may obtain a copy of the License at
007     *
008     *      http://www.apache.org/licenses/LICENSE-2.0
009     *
010     *  Unless required by applicable law or agreed to in writing, software
011     *  distributed under the License is distributed on an "AS IS" BASIS,
012     *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013     *  See the License for the specific language governing permissions and
014     *  limitations under the License.
015     */
016    package org.joda.time.tz;
017    
018    import java.util.Set;
019    
020    import org.joda.time.DateTimeZone;
021    
022    /**
023     * Service provider factory for time zones.
024     *
025     * @author Brian S O'Neill
026     * @since 1.0
027     */
028    public interface Provider {
029    
030        /**
031         * Retrieves a DateTimeZone for the given id. All providers must at
032         * least support id "UTC".
033         *
034         * @return null if not found
035         */
036        DateTimeZone getZone(String id);
037    
038        /**
039         * Returns an unmodifiable set of ids. All providers must at least
040         * support id "UTC".
041         */        
042        Set<String> getAvailableIDs();
043    
044    }