apache的commons-net包下面有ntp相关的实现类,主要类有:
1
| org.apache.commons.net.ntp.NTPUDPClient
|
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1
| org.apache.commons.net.ntp.TimeInfo
|
类NTPUDPClient中相关方法:
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1
| TimeInfo getTime(InetAddress host, int port) throws IOException
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1
| TimeInfo getTime(InetAddress host) throws IOException
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其中,第二个重载方法使用协议规范默认端口:123。
Java代码段:
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
| public static void main(String[] args) throws IOException {
try {
NTPUDPClient timeClient = new NTPUDPClient();
String timeServerUrl = "202.120.2.101" ;
InetAddress timeServerAddress = InetAddress.getByName(timeServerUrl);
TimeInfo timeInfo = timeClient.getTime(timeServerAddress);
TimeStamp timeStamp = timeInfo.getMessage().getTransmitTimeStamp();
Date date = timeStamp.getDate();
System.out.println(date);
DateFormat dateFormat = new SimpleDateFormat( "yyyy-MM-dd hh:mm:ss" );
System.out.println(dateFormat.format(date));
} catch (UnknownHostException e) {
e.printStackTrace();
}
}
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运行结果为:
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| Thu Dec 03 16 : 16 : 50 CST 2015
2015 - 12 - 03 04 : 16 : 50
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附:常用速度较快NTP服务器地址:
ntp.sjtu.edu.cn 202.120.2.101 (上海交通大学网络中心NTP服务器地址下载地址 )
time-a.nist.gov 129.6.15.28 NIST, Gaithersburg, Maryland time-b.nist.gov 129.6.15.29 NIST, Gaithersburg, Maryland time-a.timefreq.bldrdoc.gov 132.163.4.101 NIST, Boulder, Colorado time-b.timefreq.bldrdoc.gov 132.163.4.102 NIST, Boulder, Colorado time-c.timefreq.bldrdoc.gov 132.163.4.103 NIST, Boulder, Colorado
原标题:Java代码获取NTP服务器时间
关键词:JAVA