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 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 »ñÈ¡Ô­×ÓÖÓµÄʱ¼ä£¬²¢ÉèÖÃΪϵͳʱ¼ä
* @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"));
// JavaʹÓõIJÎÕÕ±ê×¼ÊÇ1970Ä꣬¶øʱ¼ä·þÎñÆ÷·µ»ØµÄÃëÊÇÏ൱1900ÄêµÄ£¬ËãÒ»ÏÂÆ«ÒÆ
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) {