net.time4j.clock

Class SntpConnector

java.lang.Object

net.time4j.clock.AbstractClock

net.time4j.clock.NetTimeConnector<SntpConfiguration>

net.time4j.clock.SntpConnector

All Implemented Interfaces:

TimeSource<Moment>

public class SntpConnector
extends NetTimeConnector<SntpConfiguration>

Connects to a modern time server using the NTP-protocol.

This class needs a socket connection via the port 123. The exact configuration can be set in the constructors but can also be changed at runtime. For safer protection against arbitrary local clock adjustments which might affect this clock, applications should also consider setting the system property "net.time4j.systemclock.nanoTime" to the value "true".

Since:

2.1

Author:

Meno Hochschild

Constructor Summary

Constructors

Constructor and Description
SntpConnector() Creates a new instance which is configured by a ServiceLoader.
SntpConnector(SntpConfiguration ntc) Creates a new instance which is configured by given argument.
SntpConnector(String server) Creates a new instance which uses a default configuration using the specified NTP4-server.

Method Summary

Methods

Modifier and Type	Method and Description
long	currentTimeInMicros() Returns the current time in microseconds since the Unix epoch [1970-01-01T00:00:00,000000Z].
long	currentTimeInMillis() Returns the current time in milliseconds since the Unix epoch [1970-01-01T00:00:00,000Z].
protected Moment	doConnect() Will be called by connect().
protected Class<SntpConfiguration>	getConfigurationType() Yields the configuration type.
SntpMessage	getLastReply() Returns the last received message of the NTP-server.
protected SntpConfiguration	loadNetTimeConfiguration() Loads the configuration parameters via a ServiceLoader.

Methods inherited from class net.time4j.clock.NetTimeConnector

connect, currentTime, getLastConnectionTime, getLastOffsetInMicros, getNetTimeConfiguration, isLogEnabled, isRunning, log, reconfigure, setLogWriter

Methods inherited from class net.time4j.clock.AbstractClock

inLocalView, inZonalView, inZonalView

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

SntpConnector

public SntpConnector()

Creates a new instance which is configured by a ServiceLoader.

Throws:

IllegalStateException - if no configuration could be found

See Also:

ServiceLoader

SntpConnector

public SntpConnector(SntpConfiguration ntc)

Creates a new instance which is configured by given argument.

Parameters:

ntc - SNTP-configuration

SntpConnector

public SntpConnector(String server)

Creates a new instance which uses a default configuration using the specified NTP4-server.

Example:

  SntpConnector clock = new SntpConnector("ptbtime1.ptb.de");
  clock.connect();
  System.out.println(clock.currentTime());
 

Parameters:

server - NTP4-server

Method Detail

currentTimeInMillis

public long currentTimeInMillis()

Returns the current time in milliseconds since the Unix epoch [1970-01-01T00:00:00,000Z].

UTC leap seconds are never counted.

Returns:

count of milliseconds since UNIX-epoch without leap seconds

Since:

2.1

currentTimeInMicros

public long currentTimeInMicros()

Returns the current time in microseconds since the Unix epoch [1970-01-01T00:00:00,000000Z].

UTC leap seconds are never counted.

Returns:

count of microseconds since UNIX-epoch without leap seconds

Since:

2.1

getLastReply

public SntpMessage getLastReply()

Returns the last received message of the NTP-server.

Returns:

server message or null if not yet received

Since:

2.1

See Also:

NetTimeConnector.connect()

doConnect

protected Moment doConnect()
                    throws IOException

Description copied from class: NetTimeConnector

Will be called by connect().

Specified by:

doConnect in class NetTimeConnector<SntpConfiguration>

Returns:

queried current time

Throws:

IOException - in case of any connection failure

See Also:

NetTimeConnector.connect()

loadNetTimeConfiguration

protected SntpConfiguration loadNetTimeConfiguration()

Description copied from class: NetTimeConnector

Loads the configuration parameters via a ServiceLoader.

Subclasses should always start by calling super.loadNetTimeConfiguration() if this method is overridden.

Overrides:

loadNetTimeConfiguration in class NetTimeConnector<SntpConfiguration>

Returns:

loaded configuration parameters

See Also:

NetTimeConnector.reconfigure()

getConfigurationType

protected Class<SntpConfiguration> getConfigurationType()

Description copied from class: NetTimeConnector

Yields the configuration type.

Specified by:

getConfigurationType in class NetTimeConnector<SntpConfiguration>

Returns:

configuration type