1/*
2 * Copyright (C) 2010 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 android.util;
18
19/**
20 * Singleton helper class for lazily initialization.
21 *
22 * Modeled after frameworks/base/include/utils/Singleton.h
23 *
24 * @hide
25 */
26public abstract class Singleton<T> {
27    private T mInstance;
28
29    protected abstract T create();
30
31    public final T get() {
32        synchronized (this) {
33            if (mInstance == null) {
34                mInstance = create();
35            }
36            return mInstance;
37        }
38    }
39}
40