Android增加SNTP网络时间同步功能
因为android的网络时间同步只支持NITZ协议 可能是国外的运营商这些都是肯定有的 所以在中国这个网络时间同步就显得很不足 因为国内很多基站都不支持NITZ 我们如果要让这个网络时间同步功能能够和他的名字对等 就得加上补救措施 用SNTP来补充做时间校对。
1.监听网络是不是连接上了
packages/apps/Settings/AndroidManifest.xml
<receiver android:name=".widget.SettingsAppWidgetProvider"
android:label="@string/gadget_title" android:exported="false">
<intent-filter>
<action android:name="android.appwidget.action.APPWIDGET_UPDATE" />
<action android:name="android.net.wifi.WIFI_STATE_CHANGED" />
<action android:name="android.net.conn.BACKGROUND_DATA_SETTING_CHANGED" />
<action android:name="android.bluetooth.adapter.action.STATE_CHANGED" />
<action android:name="android.location.PROVIDERS_CHANGED" />
<action android:name="com.android.sync.SYNC_CONN_STATUS_CHANGED" />
<action android:name="android.net.conn.CONNECTIVITY_CHANGE"/>
</intent-filter>
<meta-data android:name="android.appwidget.provider" android:resource="@xml/appwidget_info" />
</receiver>
<service android:name=".SNTP" android:exported="true" android:process=":remote"></service>
添加SNTP service
<service android:name=".SNTP"
android:exported="true"
android:process=":remote">
</service>
packages/apps/Settings/src/com/android/settings/widget/SettingsAppWidgetProvider.java
796 private boolean getAutoState(Context context) {
797 try {
798 return Settings.System.getInt(context.getContentResolver(),
799 Settings.System.AUTO_TIME) > 0;
800 } catch (SettingNotFoundException snfe) {
801 // return true;
802 // moon
803 return false;
804 }
805 }
847 }else if (action.equals(ConnectivityManager.CONNECTIVITY_ACTION)) {
848 ConnectivityManager connManager = (ConnectivityManager) context.getSystemService(Context. CONNECTIVITY_SERVICE);
849 if (null != connManager && null != connManager.getActiveNetworkInfo()) {
850 State state = connManager.getActiveNetworkInfo().getState();
851 Log.i("tag", "state===============" + state);
852 if (State.CONNECTED == state) {
853 if(getAutoState(context))
854 context.startService(new Intent(context, SNTP.class));
855 }
856 }
857 }else {
2. 在网络时间同步的那个checkbox refrence点击事件里加上（防止开始没有点开同步 但是连上网了 那么不应该进行校时 要等这个时候才可以校时）
packages/apps/Settings/src/com/android/settings/DateTimeSettings.java
} else if (key.equals(KEY_AUTO_TIME)) {
250 boolean autoEnabled = preferences.getBoolean(key, false);
251 //xxw
252 if( autoEnabled ){
253 Intent intent = new Intent(DateTimeSettings.this,SNTP.class);
254 intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
255 startService(intent);
256 }else{
257 Intent intent = new Intent(DateTimeSettings.this,SNTP.class);
258 stopService(intent) ;
259 }
260 //xxw .
最后SNTP.java
package com.android.settings;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.util.Calendar;
import java.util.TimeZone;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.os.SystemClock;
import android.text.format.DateFormat;
import android.util.Log;
import android.content.Context;
import android.os.Handler;
import android.app.Service;
import android.os.IBinder;
/**
* {@hide} Simple SNTP client class for retrieving network time. Sample usage:
*
* <pre>
* SntpClient client = new SntpClient();
* if (client.requestTime("203.117.180.36")) {
* long now = client.getNtpTime() + SystemClock.elapsedRealtime() - client.getNtpTimeReference();
* }
* </pre>
*/
public class SNTP extends Service {
private static final String TAG = "SNTP--->";
private static final boolean DBUG = true;
private static Context mContext;
/*
* public static void SNTP( Context context ) { mContext = context ; }
*/
@Override
public IBinder onBind(Intent intent) {
// TODO Auto-generated method stub
return null;
}
@Override
public void onDestroy() {
mSntpHandler.removeCallbacks(mSntpTask);
if (DBUG)
Log.d(TAG, " SNTP Service end !! ");
}
@Override
public void onStart(Intent intent, int startId) {
super.onStart(intent, startId);
if (DBUG)
Log.d(TAG, " start SNTP Service !! ");
startSyncSNTP();
}
public void startSyncSNTP() {
mSntpHandler.postDelayed(mSntpTask, 10);
}
private Handler mSntpHandler = new Handler();
private Runnable mSntpTask = new Runnable() {
public void run() {
// mSntpHandler.removeCallbacks(mSntpTask);
// if (!syncSNTP()) {
// mSntpHandler.postDelayed(mSntpTask, 3000);
// }
syncSNTP();
}
};
public boolean syncSNTP() {
SntpClient client = new SntpClient();
if (client.requestTime("203.117.180.36", 3000)) {
long now = client.getNtpTime() + SystemClock.elapsedRealtime()
- client.getNtpTimeReference();
// Calendar ca = Calendar.getInstance(TimeZone.getDefault());
// ca.getTimeInMillis();
if(now - System.currentTimeMillis()<5000) return false;
CharSequence ch = DateFormat.format("hh:mm:ss", now);
if (DBUG)
Log.d(TAG, "ch=" + ch);
CharSequence date = DateFormat.format("yyyy MM dd", now);
if (DBUG)
Log.d(TAG, "date=" + date);
if (SystemClock.setCurrentTimeMillis(now)) {
if (DBUG)
Log.d(TAG, "set Current Time =" + System.currentTimeMillis());
} else {
if (DBUG)
Log.d(TAG, " set Current Time false !");
}
} else {
if (DBUG)
Log.d(TAG, "sntp request time false !!");
return false;
}
return true;
}
public class SntpClient {
private static final int NTP_PACKET_SIZE = 48;
private static final int NTP_PORT = 123;
private static final int NTP_MODE_CLIENT = 3;
private static final int NTP_VERSION = 3;
/*
* Number of seconds between Jan 1, 1900 and Jan 1, 1970 70 years plus
* 17 leap days
*/
private static final long OFFSET_1900_TO_1970 = ((365L * 70L) + 17L) * 24L * 60L * 60L;
private static final int TRANSMIT_TIME_OFFSET = 40;
private static final int ORIGINATE_TIME_OFFSET = 24;
private static final int RECEIVE_TIME_OFFSET = 32;
// system time computed from NTP server response
private long mNtpTime;
// value of SystemClock.elapsedRealtime() corresponding to mNtpTime
private long mNtpTimeReference;
// round trip time in milliseconds
private long mRoundTripTime;
public boolean requestTime(String host, int timeout) {
try {
DatagramSocket socket = new DatagramSocket();
socket.setSoTimeout(timeout);
InetAddress address = InetAddress.getByName(host);
byte[] buffer = new byte[NTP_PACKET_SIZE];
DatagramPacket request = new DatagramPacket(buffer, buffer.length, address,
NTP_PORT);
/*
* set mode = 3 (client) and version = 3 mode is in low 3 bits
* of first byte version is in bits 3-5 of first byte
*/
buffer[0] = NTP_MODE_CLIENT | (NTP_VERSION << 3);
// get current time and write it to the request packet
long requestTime = System.currentTimeMillis();
if (DBUG)
Log.d(TAG, "System.currentTimeMillis(): " + requestTime + " ms");
long requestTicks = SystemClock.elapsedRealtime();
writeTimeStamp(buffer, TRANSMIT_TIME_OFFSET, requestTime);
socket.send(request);
// read the response
DatagramPacket response = new DatagramPacket(buffer, buffer.length);
socket.receive(response);
long responseTicks = SystemClock.elapsedRealtime();
long responseTime = requestTime + (responseTicks - requestTicks);
socket.close();
// extract the results
long originateTime = readTimeStamp(buffer, ORIGINATE_TIME_OFFSET);
long receiveTime = readTimeStamp(buffer, RECEIVE_TIME_OFFSET);
long transmitTime = readTimeStamp(buffer, TRANSMIT_TIME_OFFSET);
long roundTripTime = responseTicks - requestTicks - (transmitTime - receiveTime);
long clockOffset = (receiveTime - originateTime) + (transmitTime - responseTime);
if (DBUG)
Log.d(TAG, "round trip: " + roundTripTime + " ms");
if (DBUG)
Log.d(TAG, "clock offset: " + clockOffset + " ms");
// save our results
mNtpTime = receiveTime;// requestTime + clockOffset;
mNtpTimeReference = requestTicks;
mRoundTripTime = roundTripTime;
} catch (Exception e) {
// TODO: handle exception
if (DBUG)
Log.d(TAG, "error: " + e);
return false;
}
return true;
}
/**
* Returns the time computed from the NTP transaction.
*
* @return time value computed from NTP server response.
*/
public long getNtpTime() {
return mNtpTime;
}
/**
* Returns the reference clock value (value of
* SystemClock.elapsedRealtime()) corresponding to the NTP time.
*
* @return reference clock corresponding to the NTP time.
*/
public long getNtpTimeReference() {
return mNtpTimeReference;
}
/**
* Returns the round trip time of the NTP transaction
*
* @return round trip time in milliseconds.
*/
public long getRoundTripTime() {
return mRoundTripTime;
}
/**
* Reads an unsigned 32 bit big endian number from the given offset in
* the buffer.
*/
private long read32(byte[] buffer, int offset) {
byte b0 = buffer[offset];
byte b1 = buffer[offset + 1];
byte b2 = buffer[offset + 2];
byte b3 = buffer[offset + 3];
// convert signed bytes to unsigned values
int i0 = ((b0 & 0x80) == 0x80 ? (b0 & 0x7F) + 0x80 : b0);
int i1 = ((b1 & 0x80) == 0x80 ? (b1 & 0x7F) + 0x80 : b1);
int i2 = ((b2 & 0x80) == 0x80 ? (b2 & 0x7F) + 0x80 : b2);
int i3 = ((b3 & 0x80) == 0x80 ? (b3 & 0x7F) + 0x80 : b3);
return ((long) i0 << 24) + ((long) i1 << 16) + ((long) i2 << 8) + (long) i3;
}
/**
* Reads the NTP time stamp at the given offset in the buffer and
* returns it as a system time (milliseconds since January 1, 1970).
*/
private long readTimeStamp(byte[] buffer, int offset) {
long seconds = read32(buffer, offset);
long fraction = read32(buffer, offset + 4);
return ((seconds - OFFSET_1900_TO_1970) * 1000) + ((fraction * 1000L) / 0x100000000L);
}
/**
* Writes system time (milliseconds since January 1, 1970) as an NTP
* time stamp at the given offset in the buffer.
*/
private void writeTimeStamp(byte[] buffer, int offset, long time) {
long seconds = time / 1000L;
long milliseconds = time - seconds * 1000L;
seconds += OFFSET_1900_TO_1970;
// write seconds in big endian format
buffer[offset++] = (byte) (seconds >> 24);
buffer[offset++] = (byte) (seconds >> 16);
buffer[offset++] = (byte) (seconds >> 8);
buffer[offset++] = (byte) (seconds >> 0);
long fraction = milliseconds * 0x100000000L / 1000L;
// write fraction in big endian format
buffer[offset++] = (byte) (fraction >> 24);
buffer[offset++] = (byte) (fraction >> 16);
buffer[offset++] = (byte) (fraction >> 8);
// low order bits should be random data
buffer[offset++] = (byte) (Math.random() * 255.0);
}
}// class SntpClient
}