1 /*
2 * Copyright 2001-2009 Stephen Colebourne
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 package org.joda.time.tz;
17
18 import java.util.Collections;
19 import java.util.Set;
20
21 import org.joda.time.DateTimeZone;
22
23 /**
24 * Simple time zone provider that supports only UTC.
25 * <p>
26 * UTCProvider is thread-safe and immutable.
27 *
28 * @author Brian S O'Neill
29 * @since 1.0
30 */
31 public final class UTCProvider implements Provider {
32
33 /**
34 * Constructor.
35 */
36 public UTCProvider() {
37 super();
38 }
39
40 /**
41 * Returns {@link DateTimeZone#UTC UTC} for <code>"UTC"</code>, null
42 * otherwise.
43 */
44 public DateTimeZone getZone(String id) {
45 if ("UTC".equalsIgnoreCase(id)) {
46 return DateTimeZone.UTC;
47 }
48 return null;
49 }
50
51 /**
52 * Returns a singleton collection containing only <code>"UTC"</code>.
53 */
54 public Set<String> getAvailableIDs() {
55 return Collections.singleton("UTC");
56 }
57
58 }