001 /* 002 * Copyright 2001-2005 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.Collections; 019 import java.util.Set; 020 import org.joda.time.DateTimeZone; 021 022 /** 023 * Simple time zone provider that supports only UTC. 024 * <p> 025 * UTCProvider is thread-safe and immutable. 026 * 027 * @author Brian S O'Neill 028 * @since 1.0 029 */ 030 public final class UTCProvider implements Provider { 031 032 /** 033 * Constructor. 034 */ 035 public UTCProvider() { 036 super(); 037 } 038 039 /** 040 * Returns {@link DateTimeZone#UTC UTC} for <code>"UTC"</code>, null 041 * otherwise. 042 */ 043 public DateTimeZone getZone(String id) { 044 if ("UTC".equalsIgnoreCase(id)) { 045 return DateTimeZone.UTC; 046 } 047 return null; 048 } 049 050 /** 051 * Returns a singleton collection containing only <code>"UTC"</code>. 052 */ 053 public Set getAvailableIDs() { 054 return Collections.singleton("UTC"); 055 } 056 057 }