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.
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Field Summary
FieldsModifier and TypeFieldDescriptionprotected static final longBaseline NTP time if bit-0=0 is 7-Feb-2036 @ 06:28:16 UTCprotected static final longBaseline NTP time if bit-0=1 is 1-Jan-1900 @ 01:00:00 UTCstatic final StringDefault NTP date string format. -
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 TypeMethodDescriptionintCompares two Timestamps numerically.protected static longdecodeNtpHexString(String hexString) Convert NTP timestamp hexstring (e.g.booleanCompares this object against the specified object.static TimeStampConstructs a NTP timestamp object and initializes it so that it represents the time at which it was allocated, measured to the nearest millisecond.getDate()Converts NTP timestamp to Java Date object.longReturns low-order 32-bits representing the fractional seconds.static TimeStampgetNtpTime(long dateMillis) Helper method to convert Java time to NTP timestamp object.longReturns high-order 32-bits representing the seconds of this NTP timestamp.longgetTime()Converts NTP timestamp to Java standard time.static longgetTime(long ntpTimeValue) Converts 64-bit NTP timestamp to Java standard time.inthashCode()Computes a hash code for this Timestamp.longntpValue()Returns the value of this Timestamp as a long value.static TimeStampParses the string argument as a NTP hexidecimal timestamp representation string (e.g.Converts thisTimeStampobject to aStringof the form:protected static longtoNtpTime(long millis) Converts Java time to 64-bit NTP time representation.toString()Converts thisTimeStampobject to aString.static StringtoString(long ntpTime) Converts 64-bit NTP timestamp value to aString.Converts thisTimeStampobject to aStringof the form:
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Field Details
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msb0baseTime
Baseline NTP time if bit-0=0 is 7-Feb-2036 @ 06:28:16 UTC- See Also:
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msb1baseTime
Baseline 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.SimpleDateFormatfor code descriptions.- See Also:
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Constructor Details
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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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TimeStamp
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 hexadecimal timestamp- Throws:
NumberFormatException- - if the string does not contain a parsable timestamp.
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Method Details
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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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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.
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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 than 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:
dateMillis- the milliseconds since January 1, 1970, 00:00:00 GMT.- Returns:
- NTP timestamp object at the specified date.
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getTime
Converts 64-bit NTP timestamp to Java standard time. Note that java time (milliseconds) by definition has less precision than 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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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
Converts Java time to 64-bit NTP time representation.- Parameters:
millis- Java time- Returns:
- NTP timestamp representation of Java time value.
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toString
Converts 64-bit NTP timestamp value to aString. The NTP timestamp value is represented as hexadecimal 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 hexadecimal string with seconds separated by fractional seconds.
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compareTo
Compares two Timestamps numerically.- Specified by:
compareToin interfaceComparable<TimeStamp>- Parameters:
anotherTimeStamp- - theTimeStampto be compared.- Returns:
- the value
0if the argument TimeStamp is equal to this TimeStamp; a value less than0if this TimeStamp is numerically less than the TimeStamp argument; and a value greater than0if this TimeStamp is numerically greater than the TimeStamp argument (signed comparison).
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equals
Compares this object against the specified object. The result istrueif and only if the argument is notnulland is aLongobject that contains the samelongvalue as this object. -
getDate
Converts NTP timestamp to Java Date object.- Returns:
- NTP Timestamp in Java Date
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getFraction
Returns low-order 32-bits representing the fractional seconds.- Returns:
- fractional seconds represented by this NTP timestamp.
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getSeconds
Returns high-order 32-bits representing the seconds of this NTP timestamp.- Returns:
- seconds represented by this NTP timestamp.
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getTime
Converts NTP timestamp to Java standard time.- Returns:
- the number of milliseconds since January 1, 1970, 00:00:00 GMT represented by this NTP timestamp value.
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hashCode
Computes a hash code for this Timestamp. The result is the exclusive OR of the two halves of the primitivelongvalue represented by thisTimeStampobject. That is, the hash code is the value of the expression:(int) (this.ntpValue() ^ (this.ntpValue() >>> 32)) -
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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toDateString
Converts thisTimeStampobject to aStringof 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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toString
Converts thisTimeStampobject to aString. The NTP timestamp 64-bit long value is represented as hexadecimal string with seconds separated by fractional seconds by a decimal point; e.g. c1a089bd.fc904f6d == Tue, Dec 10 2002 10:41:49.986 -
toUTCString
Converts thisTimeStampobject to aStringof 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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