package
dtm.tools;
import
java.io.BufferedInputStream;
import
java.io.BufferedReader;
import
java.io.IOException;
import
java.io.InputStream;
import
java.io.InputStreamReader;
import
java.net.Socket;
import
java.net.UnknownHostException;
import
java.util.Calendar;
import
java.util.Date;
import
java.util.TimeZone;
import
java.util.logging.Level;
import
java.util.logging.Logger;
/**
* SyncTime 获取原子钟的时间，并设置为系统时间
*
@author
Administrator
*/
public
class
SyncTime {
private
static
int
sleepMinutes = 0;
private
static
final
long
EPOCH_OFFSET_MILLIS;
private
static
final
String[] hostName = {"time-a.nist.gov", "time-nw.nist.gov", "time.nist.gov"};
static
{
Calendar calendar = Calendar.getInstance(TimeZone.getTimeZone("GMT"));
//
Java使用的参照标准是1970年，而时间服务器返回的秒是相当1900年的，算一下偏移
calendar.set(1900, Calendar.JANUARY, 1, 0, 0, 0);
EPOCH_OFFSET_MILLIS = Math.abs(calendar.getTime().getTime());
}
public
static
void
main(String[] args) {
GetWebTime();
}
private
static
Date getNetDate(String hostName) {
Date date =
null
;
long
result = 0;
try
{
Socket socket =
new
Socket(hostName, 37);
BufferedInputStream bis =
new
BufferedInputStream(socket.getInputStream(),
socket.getReceiveBufferSize());
int
b1 = bis.read();
int
b2 = bis.read();
int
b3 = bis.read();
int
b4 = bis.read();
if
((b1 | b2 | b3 | b3) < 0) {
return
null
;
}
result = (((
long
) b1) << 24) + (b2 << 16) + (b3 << 8) + b4;
date =
new
Date(result * 1000 - EPOCH_OFFSET_MILLIS);
socket.close();
}
catch
(UnknownHostException ex) {
Logger.getLogger(SyncTime.
class
.getName()).log(Level.SEVERE,
null
, ex);
}
catch
(IOException ex) {
Logger.getLogger(SyncTime.
class
.getName()).log(Level.SEVERE,
null
, ex);
}
return
date;
}
/**
* 通过ping命令判断是否离线
*
@return
*/
public
static
boolean
offLine() {
Runtime run = Runtime.getRuntime();
try
{
Process process = run.exec("ping www.hao123.com");
InputStream s = process.getInputStream();
BufferedReader bis =
new
BufferedReader(
new
InputStreamReader(s));
String str = bis.readLine();
while
(str !=
null
) {
if
(str.startsWith("Reply from")) {
return
false
;
}
str = bis.readLine();
}
process.waitFor();
}
catch
(IOException ex) {
Logger.getLogger(SyncTime.
class
.getName()).log(Level.SEVERE,
null
, ex);
}
catch
(InterruptedException ex) {
Logger.getLogger(SyncTime.
class
.getName()).log(Level.SEVERE,
null
, ex);
}
return
true
;
}
/**
* 通过调用本地命令date和time修改计算机时间
*
@param
date
*/
private
static
void
setComputeDate(Date date) {
Calendar c = Calendar.getInstance(TimeZone.getTimeZone("GMT+8"));
c.setTime(date);
int
year = c.get(Calendar.YEAR);
int
month = c.get(Calendar.MONTH) + 1;
int
day = c.get(Calendar.DAY_OF_MONTH);
int
hour = c.get(Calendar.HOUR_OF_DAY);
int
minute = c.get(Calendar.MINUTE);
int
second = c.get(Calendar.SECOND);
c.setTime(
new
Date());
int
year_c = c.get(Calendar.YEAR);
int
month_c = c.get(Calendar.MONTH) + 1;
int
day_c = c.get(Calendar.DAY_OF_MONTH);
int
hour_c = c.get(Calendar.HOUR_OF_DAY);
int
minute_c = c.get(Calendar.MINUTE);
String ymd = year + "-" + month + "-" + day;
String time = hour + ":" + minute + ":" + second;
try
{
//
日期不一致就修改一下日期
if
(year != year_c || month != month_c || day != day_c) {
String cmd = "cmd /c date " + ymd;
Process process = Runtime.getRuntime().exec(cmd);
process.waitFor();
}
//
时间不一致就修改一下时间
if
(hour != hour_c || minute != minute_c) {
String cmd = "cmd /c time " + time;
Process process = Runtime.getRuntime().exec(cmd);
process.waitFor();
}
}
catch
(IOException ex) {
Logger.getLogger(SyncTime.
class
.getName()).log(Level.SEVERE,
null
, ex);
}
catch
(InterruptedException ex) {
Logger.getLogger(SyncTime.
class
.getName()).log(Level.SEVERE,
null
, ex);
}
}
public
static
void
GetWebTime()
{
//
检测电脑是否在线
while
(offLine() && sleepMinutes < 30) {
try
{
Thread.sleep(120000);
sleepMinutes += 2;
}
catch
(InterruptedException ex) {
Logger.getLogger(SyncTime.
class
.getName()).log(Level.SEVERE,
null
, ex);
}
}
//
30分钟还没有联线，表示就不上网了，退出吧
if
(sleepMinutes >= 30)
{
System.exit(0);
}
//
从网络上获取时间
Date date =
null
;
for
(
int
i = 0; i < hostName.length; i++) {
date = getNetDate(hostName[i]);
if
(date !=
null
) {
break
;
}
}
//
修改本机时间
if
(date !=
null
) {
System.out.println("原子钟时间："+date);
setComputeDate(date);
}
}
}
