Android network time synchronization -7. 1

I. Introduction

Android devices have two ways to synchronize time. One way is to manually adjust the time. One is to use the time provided by the network.

note:

The source code comes from Android 7. 1.

Second, a detailed introduction

Note: This article focuses on the services related to network synchronization.

1.app terminal

By setting the settings. That is, Global.AUTO_TIME

Settings. Global.putint (mcontext.getcontentresolver (), setting. Global automatic time,

isChecked？ 1 : 0);

1 stands for on.

0 means off.

2. System server-network time update service

1) ADB quick query mode

Adb shell dumpsys network _ time _ update _ service

Understand several key variables

Understand the real implementation method

2) Details of business implementation

Knowledge supplement:

Knowledge point one,

DatagramSocket

data clustering

DatagramSocket socket = null

This SNTP protocol for socket communication is also very good.

Knowledge point 2

System.currentTimeMillis

System clock. elapse real-time

Where and how to get the startup time?

Reference learning