Java tutorial
/* * Copyright (C) 2015 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License */ package android.support.v4.content; import android.content.SharedPreferences; import android.os.Build; import android.support.annotation.NonNull; public final class SharedPreferencesCompat { public final static class EditorCompat { private static EditorCompat sInstance; private interface Helper { void apply(@NonNull SharedPreferences.Editor editor); } private static class EditorHelperBaseImpl implements Helper { @Override public void apply(@NonNull SharedPreferences.Editor editor) { editor.commit(); } } private static class EditorHelperApi9Impl implements Helper { @Override public void apply(@NonNull SharedPreferences.Editor editor) { EditorCompatGingerbread.apply(editor); } } private final Helper mHelper; private EditorCompat() { if (Build.VERSION.SDK_INT >= 9) { mHelper = new EditorHelperApi9Impl(); } else { mHelper = new EditorHelperBaseImpl(); } } public static EditorCompat getInstance() { if (sInstance == null) { sInstance = new EditorCompat(); } return sInstance; } public void apply(@NonNull SharedPreferences.Editor editor) { mHelper.apply(editor); } } private SharedPreferencesCompat() { } }