NTP流程

最新推荐文章于 2025-07-25 18:12:43 发布

原创最新推荐文章于 2025-07-25 18:12:43 发布 · 329 阅读

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#java #visual studio

NTP时间：

SntpClient：具体网络UDP请求
路径：base/core/java/android/net/SntpClient.java

NtpTrustedTime:单例
路径：base/core/java/android/util/NtpTrustedTime.java

参数获取

final String defaultServer = res.getString(com.android.internal.R.string.config_ntpServer);
final long defaultTimeout = res.getInteger(com.android.internal.R.integer.config_ntpTimeout);
final String secureServer = Settings.Global.getString(resolver, Settings.Global.NTP_SERVER);
final long timeout = Settings.Global.getLong(resolver, Settings.Global.NTP_TIMEOUT, defaultTimeout);

备份服务器

private static final String BACKUP_SERVER = "persist.backup.ntpServer";
final String sserver_prop = Settings.Global.getString(resolver, Settings.Global.NTP_SERVER_2);
final String secondServer_prop = ((null != sserver_prop)&& (0 < sserver_prop.length()))? sserver_prop : BACKUP_SERVER;

#文件路径：base/core/res/res/values/config.xml
<string translatable="false" name="config_ntpServer">time.android.com</string>
<integer name="config_ntpPollingInterval">86400000</integer>
<integer name="config_ntpPollingIntervalShorter">60000</integer>
<integer name="config_ntpRetry">3</integer>
<integer name="config_ntpThreshold">5000</integer>
<integer name="config_ntpTimeout">5000</integer>

#文件路径：base/core/java/android/provider/Settings.java
/** Preferred NTP server. {@hide} */
public static final String NTP_SERVER = "ntp_server";
/** Timeout in milliseconds to wait for NTP server. {@hide} */
public static final String NTP_TIMEOUT = "ntp_timeout";
   　/** Secondary NTP server. {@hide} */
public static final String NTP_SERVER_2 = "ntp_server_2";

查看数据库如下：

msm8953_64:/ # settings get global ntp_server
null
msm8953_64:/ # settings get global ntp_timeout
null
msm8953_64:/ # settings get global ntp_server_2
persist.vendor.ntp.svr_2
msm8953_64:/ # getprop persist.vendor.ntp.svr_2
cn.ntp.org.cn
msm8953_64:/ #

更新时间三种方式：

AUTO_TIME数据库字段变化,无论开关都触发
收到广播 private static final String ACTION_POLL =“com.android.server.NetworkTimeUpdateService.action.POLL”;
网络状态变化回调：NetworkCallback

修改方案：

修改默认数据库字段：AUTO_TIME 为0

base/packages/SettingsProvider/res/values/defaults.xml
<bool name="def_auto_time">false</bool>// 如果之前是true 需要升级数据库，需要小心

//base/services/core/java/com/android/server/NewNetworkTimeUpdateService.java
private void onPollNetworkTime(int event) {
        if (!isAutomaticTimeRequested()) {
            if(DBG) Log.d(TAG,"onPollNetworkTime but auto_time is false");
            return;
}


//base/services/core/java/com/android/server/location/NtpTimeHelper.java
private boolean isAutomaticTime() {
	if (resolver != null)
	    return Settings.Global.getInt(resolver, Settings.Global.AUTO_TIME, 0) != 0;
	    return false;
	}
	
synchronized void retrieveAndInjectNtpTime()
	if (!isAutomaticTime()) {
	     if (DEBUG) Log.d(TAG, "retrieveAndInjectNtpTime but auto_time is false");
	         return;
	}

抓日志：

logcat -s SntpClient NtpTimeHelper NetworkTimeUpdateService