1/*
2 * Copyright (C) 2008 The Android Open Source Project
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
17package org.apache.harmony.luni.internal.util;
18
19/**
20 * This class provides a way to add an implementation specific way to
21 * access the current timezone.
22 */
23public abstract class TimezoneGetter {
24
25    private static TimezoneGetter instance;
26
27    /**
28     * Retrieves the singleton instance of this class.
29     *
30     * @return TimezoneGetter the single instance of this class.
31     */
32    public static TimezoneGetter getInstance() {
33        return instance;
34    }
35
36    /**
37     * Sets the singleton instance of this class.
38     *
39     * @param instance
40     *            TimezoneGetter the single instance of this class.
41     */
42    public static void setInstance(TimezoneGetter getter) {
43        if (instance != null) {
44            throw new UnsupportedOperationException("TimezoneGetter instance already set");
45        }
46        instance = getter;
47    }
48
49    /**
50     * Retrieves the ID of the current time zone.
51     *
52     * @return String the ID of the current time zone.
53     */
54    public abstract String getId();
55}
56