Package org.apache.commons.net.ntp
Class TimeStamp
java.lang.Object
org.apache.commons.net.ntp.TimeStamp
- All Implemented Interfaces:
Serializable
,Comparable<TimeStamp>
TimeStamp class represents the Network Time Protocol (NTP) timestamp
as defined in RFC-1305 and SNTP (RFC-2030). It is represented as a
64-bit unsigned fixed-point number in seconds relative to 0-hour on 1-January-1900.
The 32-bit low-order bits are the fractional seconds whose precision is
about 200 picoseconds. Assumes overflow date when date passes MAX_LONG
and reverts back to 0 is 2036 and not 1900. Test for most significant
bit: if MSB=0 then 2036 basis is used otherwise 1900 if MSB=1.
Methods exist to convert NTP timestamps to and from the equivalent Java date representation, which is the number of milliseconds since the standard base time known as "the epoch", namely January 1, 1970, 00:00:00 GMT.
- Version:
- $Revision: 1741829 $
- See Also:
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Field Summary
FieldsModifier and TypeFieldDescriptionprotected static final long
baseline NTP time if bit-0=0 is 7-Feb-2036 @ 06:28:16 UTCprotected static final long
baseline NTP time if bit-0=1 is 1-Jan-1900 @ 01:00:00 UTCstatic final String
Default NTP date string format.private final long
NTP timestamp value: 64-bit unsigned fixed-point number as defined in RFC-1305 with high-order 32 bits the seconds field and the low-order 32-bits the fractional field.private static final long
private DateFormat
private DateFormat
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Constructor Summary
ConstructorsConstructorDescriptionTimeStamp
(long ntpTime) Constructs a newly allocated NTP timestamp object that represents the native 64-bit long argument.Constructs a newly allocated NTP timestamp object that represents the value represented by the string in hexdecimal form (e.g.Constructs a newly allocated NTP timestamp object that represents the Java Date argument. -
Method Summary
Modifier and TypeMethodDescriptionprivate static void
appendHexString
(StringBuilder buf, long l) Left-pad 8-character hex string with 0'sint
Compares two Timestamps numerically.protected static long
decodeNtpHexString
(String hexString) Convert NTP timestamp hexstring (e.g.boolean
Compares this object against the specified object.static TimeStamp
Constructs a NTP timestamp object and initializes it so that it represents the time at which it was allocated, measured to the nearest millisecond.getDate()
Convert NTP timestamp to Java Date object.long
Returns low-order 32-bits representing the fractional seconds.static TimeStamp
getNtpTime
(long date) Helper method to convert Java time to NTP timestamp object.long
Returns high-order 32-bits representing the seconds of this NTP timestamp.long
getTime()
Convert NTP timestamp to Java standard time.static long
getTime
(long ntpTimeValue) Convert 64-bit NTP timestamp to Java standard time.int
hashCode()
Computes a hashcode for this Timestamp.long
ntpValue()
Returns the value of this Timestamp as a long value.static TimeStamp
Parses the string argument as a NTP hexidecimal timestamp representation string (e.g.Converts thisTimeStamp
object to aString
of the form:protected static long
toNtpTime
(long t) Converts Java time to 64-bit NTP time representation.toString()
Converts thisTimeStamp
object to aString
.static String
toString
(long ntpTime) Converts 64-bit NTP timestamp value to aString
.Converts thisTimeStamp
object to aString
of the form:
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Field Details
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serialVersionUID
private static final long serialVersionUID- See Also:
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msb0baseTime
protected static final long msb0baseTimebaseline NTP time if bit-0=0 is 7-Feb-2036 @ 06:28:16 UTC- See Also:
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msb1baseTime
protected static final long msb1baseTimebaseline NTP time if bit-0=1 is 1-Jan-1900 @ 01:00:00 UTC- See Also:
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NTP_DATE_FORMAT
Default NTP date string format. E.g. Fri, Sep 12 2003 21:06:23.860. Seejava.text.SimpleDateFormat
for code descriptions.- See Also:
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ntpTime
private final long ntpTimeNTP timestamp value: 64-bit unsigned fixed-point number as defined in RFC-1305 with high-order 32 bits the seconds field and the low-order 32-bits the fractional field. -
simpleFormatter
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utcFormatter
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Constructor Details
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TimeStamp
public TimeStamp(long ntpTime) Constructs a newly allocated NTP timestamp object that represents the native 64-bit long argument.- Parameters:
ntpTime
- the timestamp
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TimeStamp
Constructs a newly allocated NTP timestamp object that represents the value represented by the string in hexdecimal form (e.g. "c1a089bd.fc904f6d").- Parameters:
hexStamp
- the hex timestamp- Throws:
NumberFormatException
- - if the string does not contain a parsable timestamp.
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TimeStamp
Constructs a newly allocated NTP timestamp object that represents the Java Date argument.- Parameters:
d
- - the Date to be represented by the Timestamp object.
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Method Details
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ntpValue
public long ntpValue()Returns the value of this Timestamp as a long value.- Returns:
- the 64-bit long value represented by this object.
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getSeconds
public long getSeconds()Returns high-order 32-bits representing the seconds of this NTP timestamp.- Returns:
- seconds represented by this NTP timestamp.
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getFraction
public long getFraction()Returns low-order 32-bits representing the fractional seconds.- Returns:
- fractional seconds represented by this NTP timestamp.
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getTime
public long getTime()Convert NTP timestamp to Java standard time.- Returns:
- NTP Timestamp in Java time
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getDate
Convert NTP timestamp to Java Date object.- Returns:
- NTP Timestamp in Java Date
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getTime
public static long getTime(long ntpTimeValue) Convert 64-bit NTP timestamp to Java standard time. Note that java time (milliseconds) by definition has less precision then NTP time (picoseconds) so converting NTP timestamp to java time and back to NTP timestamp loses precision. For example, Tue, Dec 17 2002 09:07:24.810 EST is represented by a single Java-based time value of f22cd1fc8a, but its NTP equivalent are all values ranging from c1a9ae1c.cf5c28f5 to c1a9ae1c.cf9db22c.- Parameters:
ntpTimeValue
- the input time- Returns:
- the number of milliseconds since January 1, 1970, 00:00:00 GMT represented by this NTP timestamp value.
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getNtpTime
Helper method to convert Java time to NTP timestamp object. Note that Java time (milliseconds) by definition has less precision then NTP time (picoseconds) so converting Ntptime to Javatime and back to Ntptime loses precision. For example, Tue, Dec 17 2002 09:07:24.810 is represented by a single Java-based time value of f22cd1fc8a, but its NTP equivalent are all values from c1a9ae1c.cf5c28f5 to c1a9ae1c.cf9db22c.- Parameters:
date
- the milliseconds since January 1, 1970, 00:00:00 GMT.- Returns:
- NTP timestamp object at the specified date.
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getCurrentTime
Constructs a NTP timestamp object and initializes it so that it represents the time at which it was allocated, measured to the nearest millisecond.- Returns:
- NTP timestamp object set to the current time.
- See Also:
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decodeNtpHexString
Convert NTP timestamp hexstring (e.g. "c1a089bd.fc904f6d") to the NTP 64-bit unsigned fixed-point number.- Parameters:
hexString
- the string to convert- Returns:
- NTP 64-bit timestamp value.
- Throws:
NumberFormatException
- - if the string does not contain a parsable timestamp.
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parseNtpString
Parses the string argument as a NTP hexidecimal timestamp representation string (e.g. "c1a089bd.fc904f6d").- Parameters:
s
- - hexstring.- Returns:
- the Timestamp represented by the argument in hexidecimal.
- Throws:
NumberFormatException
- - if the string does not contain a parsable timestamp.
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toNtpTime
protected static long toNtpTime(long t) Converts Java time to 64-bit NTP time representation.- Parameters:
t
- Java time- Returns:
- NTP timestamp representation of Java time value.
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hashCode
public int hashCode()Computes a hashcode for this Timestamp. The result is the exclusive OR of the two halves of the primitivelong
value represented by thisTimeStamp
object. That is, the hashcode is the value of the expression:(int)(this.ntpValue()^(this.ntpValue() >>> 32))
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equals
Compares this object against the specified object. The result istrue
if and only if the argument is notnull
and is aLong
object that contains the samelong
value as this object. -
toString
Converts thisTimeStamp
object to aString
. The NTP timestamp 64-bit long value is represented as hex string with seconds separated by fractional seconds by a decimal point; e.g. c1a089bd.fc904f6d == Tue, Dec 10 2002 10:41:49.986 -
appendHexString
Left-pad 8-character hex string with 0's- Parameters:
buf
- - StringBuilder which is appended with leading 0's.l
- - a long.
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toString
Converts 64-bit NTP timestamp value to aString
. The NTP timestamp value is represented as hex string with seconds separated by fractional seconds by a decimal point; e.g. c1a089bd.fc904f6d == Tue, Dec 10 2002 10:41:49.986- Parameters:
ntpTime
- the 64 bit timestamp- Returns:
- NTP timestamp 64-bit long value as hex string with seconds separated by fractional seconds.
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toDateString
Converts thisTimeStamp
object to aString
of the form:
See java.text.SimpleDataFormat for code descriptions.EEE, MMM dd yyyy HH:mm:ss.SSS
- Returns:
- a string representation of this date.
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toUTCString
Converts thisTimeStamp
object to aString
of the form:
See java.text.SimpleDataFormat for code descriptions.EEE, MMM dd yyyy HH:mm:ss.SSS UTC
- Returns:
- a string representation of this date in UTC.
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compareTo
Compares two Timestamps numerically.- Specified by:
compareTo
in interfaceComparable<TimeStamp>
- Parameters:
anotherTimeStamp
- - theTimeStamp
to be compared.- Returns:
- the value
0
if the argument TimeStamp is equal to this TimeStamp; a value less than0
if this TimeStamp is numerically less than the TimeStamp argument; and a value greater than0
if this TimeStamp is numerically greater than the TimeStamp argument (signed comparison).
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