1 /* 2 * Copyright (C) 2018 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 17 package android.os; 18 19 import android.util.Log; 20 21 import java.time.Clock; 22 import java.time.DateTimeException; 23 import java.time.ZoneId; 24 import java.util.Arrays; 25 26 /** 27 * Single {@link Clock} that will return the best available time from a set of 28 * prioritized {@link Clock} instances. 29 * <p> 30 * For example, when {@link SystemClock#currentNetworkTimeClock()} isn't able to 31 * provide the time, this class could use {@link Clock#systemUTC()} instead. 32 * 33 * @hide 34 */ 35 public class BestClock extends SimpleClock { 36 private static final String TAG = "BestClock"; 37 38 private final Clock[] clocks; 39 40 public BestClock(ZoneId zone, Clock... clocks) { 41 super(zone); 42 this.clocks = clocks; 43 } 44 45 @Override 46 public long millis() { 47 for (Clock clock : clocks) { 48 try { 49 return clock.millis(); 50 } catch (DateTimeException e) { 51 // Ignore and attempt the next clock 52 Log.w(TAG, e.toString()); 53 } 54 } 55 throw new DateTimeException( 56 "No clocks in " + Arrays.toString(clocks) + " were able to provide time"); 57 } 58 } 59
