org.apache.commons.net.ntp

Class NtpV3Impl

java.lang.Object

org.apache.commons.net.ntp.NtpV3Impl

All Implemented Interfaces:

NtpV3Packet

public class NtpV3Impl
extends Object
implements NtpV3Packet

Implements NtpV3Packet to convert Java objects to and from the Network Time Protocol (NTP) data message header format described in RFC-1305.

Field Summary

Fields inherited from interface org.apache.commons.net.ntp.NtpV3Packet

LI_ALARM_CONDITION, LI_LAST_MINUTE_HAS_59_SECONDS, LI_LAST_MINUTE_HAS_61_SECONDS, LI_NO_WARNING, MODE_BROADCAST, MODE_CLIENT, MODE_CONTROL_MESSAGE, MODE_PRIVATE, MODE_RESERVED, MODE_SERVER, MODE_SYMMETRIC_ACTIVE, MODE_SYMMETRIC_PASSIVE, NTP_MAXCLOCK, NTP_MAXPOLL, NTP_MINCLOCK, NTP_MINPOLL, NTP_PORT, TYPE_DAYTIME, TYPE_ICMP, TYPE_NTP, TYPE_TIME, VERSION_3, VERSION_4

Constructor Summary

Constructors

Constructor and Description
NtpV3Impl() Creates a new instance of NtpV3Impl

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object obj) Compares this object against the specified object.
DatagramPacket	getDatagramPacket() Gets the datagram packet with the NTP details already filled in.
int	getLeapIndicator() Gets leap indicator as defined in RFC-1305 which is a two-bit code: 0=no warning 1=last minute has 61 seconds 2=last minute has 59 seconds 3=alarm condition (clock not synchronized)
int	getMode() Gets the mode as defined in RFC-1305 which is a 3-bit integer whose value is indicated by the MODE_xxx parameters.
String	getModeName() Gets the human-readable name of message mode type as described in RFC 1305.
TimeStamp	getOriginateTimeStamp() Gets the originate time as defined in RFC-1305.
int	getPoll() Gets the poll interval as defined in RFC-1305, which is an eight-bit signed integer indicating the maximum interval between successive messages, in seconds to the nearest power of two (e.g.
int	getPrecision() Gets the precision as defined in RFC-1305 encoded as an 8-bit signed integer (seconds to the nearest power of two).
TimeStamp	getReceiveTimeStamp() Gets the receive timestamp as defined in RFC-1305.
int	getReferenceId() Gets the reference id as defined in RFC-1305, which is a 32-bit integer whose value is dependent on several criteria.
String	getReferenceIdString() Gets the reference id string.
TimeStamp	getReferenceTimeStamp() Gets the reference time as defined in RFC-1305.
int	getRootDelay() Gets the root delay as defined in RFC-1305, which is the total roundtrip delay to the primary reference source, in seconds.
double	getRootDelayInMillisDouble() Gets the root delay as defined in RFC-1305 in milliseconds, which is the total roundtrip delay to the primary reference source, in seconds.
int	getRootDispersion() Gets the root dispersion as defined in RFC-1305.
long	getRootDispersionInMillis() Gets the root dispersion (as defined in RFC-1305) in milliseconds.
double	getRootDispersionInMillisDouble() Gets the root dispersion (as defined in RFC-1305) in milliseconds as double precision value.
int	getStratum() Gets the Stratum as defined in RFC-1305, which indicates the stratum level of the local clock, with values defined as follows: 0=unspecified, 1=primary ref clock, and all others a secondary reference (via NTP).
TimeStamp	getTransmitTimeStamp() Gets the transmit timestamp as defined in RFC-1305.
String	getType() Gets the type of time packet.
int	getVersion() Gets the NTP version number as defined in RFC-1305.
int	hashCode() Computes a hash code for this object.
void	setDatagramPacket(DatagramPacket srcDp) Sets the contents of this object from source datagram packet.
void	setLeapIndicator(int li) Sets leap indicator as defined in RFC-1305.
void	setMode(int mode) Sets mode as defined in RFC-1305.
void	setOriginateTimeStamp(TimeStamp ts) Sets originate timestamp given NTP TimeStamp object.
void	setPoll(int poll) Sets poll interval as defined in RFC-1305.
void	setPrecision(int precision) Sets precision as defined in RFC-1305.
void	setReceiveTimeStamp(TimeStamp ts) Sets receive timestamp given NTP TimeStamp object.
void	setReferenceId(int refId) Sets reference clock identifier field with 32-bit unsigned integer value.
void	setReferenceTime(TimeStamp ts) Sets Reference time with NTP timestamp.
void	setRootDelay(int delay) Sets root delay as defined in RFC-1305.
void	setRootDispersion(int dispersion) Sets root dispersion as defined in RFC-1305.
void	setStratum(int stratum) Sets stratum level as defined in RFC-1305.
void	setTransmitTime(TimeStamp ts) Sets transmit time with NTP timestamp.
void	setVersion(int version) Sets NTP version as defined in RFC-1305.
String	toString() Returns details of NTP packet as a string.
protected static int	ui(byte b) Convert byte to unsigned integer.
protected static long	ul(byte b) Convert byte to unsigned long.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

NtpV3Impl

public NtpV3Impl()

Creates a new instance of NtpV3Impl

Method Detail

equals

public boolean equals(Object obj)

Compares this object against the specified object. The result is true if and only if the argument is not null and is a NtpV3Impl object that contains the same values as this object.

Overrides:

equals in class Object

Parameters:

obj - the object to compare with.

Returns:

true if the objects are the same; false otherwise.

getDatagramPacket

public DatagramPacket getDatagramPacket()

Gets the datagram packet with the NTP details already filled in.

Specified by:

getDatagramPacket in interface NtpV3Packet

Returns:

a datagram packet.

getLeapIndicator

public int getLeapIndicator()

Gets leap indicator as defined in RFC-1305 which is a two-bit code: 0=no warning 1=last minute has 61 seconds 2=last minute has 59 seconds 3=alarm condition (clock not synchronized)

Specified by:

getLeapIndicator in interface NtpV3Packet

Returns:

leap indicator as defined in RFC-1305.

getMode

public int getMode()

Gets the mode as defined in RFC-1305 which is a 3-bit integer whose value is indicated by the MODE_xxx parameters.

Specified by:

getMode in interface NtpV3Packet

Returns:

mode as defined in RFC-1305.

getModeName

public String getModeName()

Gets the human-readable name of message mode type as described in RFC 1305.

Specified by:

getModeName in interface NtpV3Packet

Returns:

mode name as string.

getOriginateTimeStamp

public TimeStamp getOriginateTimeStamp()

Gets the originate time as defined in RFC-1305.

Specified by:

getOriginateTimeStamp in interface NtpV3Packet

Returns:

the originate time. Never returns null.

getPoll

public int getPoll()

Gets the poll interval as defined in RFC-1305, which is an eight-bit signed integer indicating the maximum interval between successive messages, in seconds to the nearest power of two (e.g. value of six indicates an interval of 64 seconds). The values that can appear in this field range from NTP_MINPOLL to NTP_MAXPOLL inclusive.

Specified by:

getPoll in interface NtpV3Packet

Returns:

poll interval as defined in RFC-1305.

getPrecision

public int getPrecision()

Gets the precision as defined in RFC-1305 encoded as an 8-bit signed integer (seconds to the nearest power of two). Values normally range from -6 to -20.

Specified by:

getPrecision in interface NtpV3Packet

Returns:

precision as defined in RFC-1305.

getReceiveTimeStamp

public TimeStamp getReceiveTimeStamp()

Gets the receive timestamp as defined in RFC-1305.

Specified by:

getReceiveTimeStamp in interface NtpV3Packet

Returns:

the receive time. Never returns null.

getReferenceId

public int getReferenceId()

Gets the reference id as defined in RFC-1305, which is a 32-bit integer whose value is dependent on several criteria.

Specified by:

getReferenceId in interface NtpV3Packet

Returns:

the reference id as defined in RFC-1305.

getReferenceIdString

public String getReferenceIdString()

Gets the reference id string. String cannot be null but value is dependent on the version of the NTP spec supported and stratum level. Value can be an empty string, clock type string, IP address, or a hexadecimal string.

Specified by:

getReferenceIdString in interface NtpV3Packet

Returns:

the reference id string.

getReferenceTimeStamp

public TimeStamp getReferenceTimeStamp()

Gets the reference time as defined in RFC-1305.

Specified by:

getReferenceTimeStamp in interface NtpV3Packet

Returns:

the reference time as TimeStamp object. Never returns null.

getRootDelay

public int getRootDelay()

Gets the root delay as defined in RFC-1305, which is the total roundtrip delay to the primary reference source, in seconds. Values can take positive and negative values, depending on clock precision and skew.

Specified by:

getRootDelay in interface NtpV3Packet

Returns:

root delay as defined in RFC-1305.

getRootDelayInMillisDouble

public double getRootDelayInMillisDouble()

Gets the root delay as defined in RFC-1305 in milliseconds, which is the total roundtrip delay to the primary reference source, in seconds. Values can take positive and negative values, depending on clock precision and skew.

Specified by:

getRootDelayInMillisDouble in interface NtpV3Packet

Returns:

root delay in milliseconds

getRootDispersion

public int getRootDispersion()

Gets the root dispersion as defined in RFC-1305.

Specified by:

getRootDispersion in interface NtpV3Packet

Returns:

root dispersion.

getRootDispersionInMillis

public long getRootDispersionInMillis()

Gets the root dispersion (as defined in RFC-1305) in milliseconds.

Specified by:

getRootDispersionInMillis in interface NtpV3Packet

Returns:

root dispersion in milliseconds

getRootDispersionInMillisDouble

public double getRootDispersionInMillisDouble()

Gets the root dispersion (as defined in RFC-1305) in milliseconds as double precision value.

Specified by:

getRootDispersionInMillisDouble in interface NtpV3Packet

Returns:

root dispersion in milliseconds

getStratum

public int getStratum()

Gets the Stratum as defined in RFC-1305, which indicates the stratum level of the local clock, with values defined as follows: 0=unspecified, 1=primary ref clock, and all others a secondary reference (via NTP).

Specified by:

getStratum in interface NtpV3Packet

Returns:

Stratum level as defined in RFC-1305.

getTransmitTimeStamp

public TimeStamp getTransmitTimeStamp()

Gets the transmit timestamp as defined in RFC-1305.

Specified by:

getTransmitTimeStamp in interface NtpV3Packet

Returns:

the transmit timestamp as defined in RFC-1305. Never returns a null object.

getType

public String getType()

Gets the type of time packet. The values (e.g. NTP, TIME, ICMP, ...) correspond to the protocol used to obtain the timing information.

Specified by:

getType in interface NtpV3Packet

Returns:

packet type string identifier which in this case is "NTP".

getVersion

public int getVersion()

Gets the NTP version number as defined in RFC-1305.

Specified by:

getVersion in interface NtpV3Packet

Returns:

NTP version number.

hashCode

public int hashCode()

Computes a hash code for this object. The result is the exclusive OR of the values of this object stored as a byte array.

Overrides:

hashCode in class Object

Returns:

a hash code value for this object.

setDatagramPacket

public void setDatagramPacket(DatagramPacket srcDp)

Sets the contents of this object from source datagram packet.

Specified by:

setDatagramPacket in interface NtpV3Packet

Parameters:

srcDp - source DatagramPacket to copy contents from, never null.

Throws:

IllegalArgumentException - if srcDp is null or byte length is less than minimum length of 48 bytes

setLeapIndicator

public void setLeapIndicator(int li)

Sets leap indicator as defined in RFC-1305.

Specified by:

setLeapIndicator in interface NtpV3Packet

Parameters:

li - leap indicator.

setMode

public void setMode(int mode)

Sets mode as defined in RFC-1305.

Specified by:

setMode in interface NtpV3Packet

Parameters:

mode - the mode to set

setOriginateTimeStamp

public void setOriginateTimeStamp(TimeStamp ts)

Sets originate timestamp given NTP TimeStamp object. If ts is null then zero time is used.

Specified by:

setOriginateTimeStamp in interface NtpV3Packet

Parameters:

ts - NTP timestamp

setPoll

public void setPoll(int poll)

Sets poll interval as defined in RFC-1305.

Specified by:

setPoll in interface NtpV3Packet

Parameters:

poll - poll interval.

setPrecision

public void setPrecision(int precision)

Sets precision as defined in RFC-1305.

Specified by:

setPrecision in interface NtpV3Packet

Parameters:

precision - the precision to set

setReceiveTimeStamp

public void setReceiveTimeStamp(TimeStamp ts)

Sets receive timestamp given NTP TimeStamp object. If ts is null then zero time is used.

Specified by:

setReceiveTimeStamp in interface NtpV3Packet

Parameters:

ts - timestamp

setReferenceId

public void setReferenceId(int refId)

Sets reference clock identifier field with 32-bit unsigned integer value. See RFC-1305 for description.

Specified by:

setReferenceId in interface NtpV3Packet

Parameters:

refId - reference clock identifier.

setReferenceTime

public void setReferenceTime(TimeStamp ts)

Sets Reference time with NTP timestamp. If ts is null then zero time is used.

Specified by:

setReferenceTime in interface NtpV3Packet

Parameters:

ts - NTP timestamp

setRootDelay

public void setRootDelay(int delay)

Sets root delay as defined in RFC-1305.

Specified by:

setRootDelay in interface NtpV3Packet

Parameters:

delay - root delay

setRootDispersion

public void setRootDispersion(int dispersion)

Sets root dispersion as defined in RFC-1305.

Specified by:

setRootDispersion in interface NtpV3Packet

Parameters:

dispersion - root dispersion

setStratum

public void setStratum(int stratum)

Sets stratum level as defined in RFC-1305.

Specified by:

setStratum in interface NtpV3Packet

Parameters:

stratum - stratum level.

setTransmitTime

public void setTransmitTime(TimeStamp ts)

Sets transmit time with NTP timestamp. If ts is null then zero time is used.

Specified by:

setTransmitTime in interface NtpV3Packet

Parameters:

ts - NTP timestamp

setVersion

public void setVersion(int version)

Sets NTP version as defined in RFC-1305.

Specified by:

setVersion in interface NtpV3Packet

Parameters:

version - NTP version.

toString

public String toString()

Returns details of NTP packet as a string.

Overrides:

toString in class Object

Returns:

details of NTP packet as a string.

ui

protected static final int ui(byte b)

Convert byte to unsigned integer. Java only has signed types, so we have to do more work to get unsigned ops.

Parameters:

b - input byte

Returns:

unsigned int value of byte

ul

protected static final long ul(byte b)

Convert byte to unsigned long. Java only has signed types, so we have to do more work to get unsigned ops

Parameters:

b - input byte

Returns:

unsigned long value of byte