org.apache.commons.net.ntp
Class TimeStamp
java.lang.Object
org.apache.commons.net.ntp.TimeStamp
- Comparable, java.io.Serializable
public class TimeStamp
extends java.lang.Object
implements java.io.Serializable, Comparable
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.
static String | NTP_DATE_FORMAT - Default NTP date string format.
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protected static long | msb0baseTime - baseline NTP time if bit-0=0 -> 7-Feb-2036 @ 06:28:16 UTC
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protected static long | msb1baseTime - baseline NTP time if bit-0=1 -> 1-Jan-1900 @ 01:00:00 UTC
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TimeStamp(Date d) -
Constructs a newly allocated NTP timestamp object
that represents the Java Date argument.
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TimeStamp(String s) -
Constructs a newly allocated NTP timestamp object
that represents the value represented by the string
in hexdecimal form (e.g.
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TimeStamp(long ntpTime) -
Constructs a newly allocated NTP timestamp object
that represents the native 64-bit long argument.
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@Override | String toString() -
Converts this
TimeStamp object to a String .
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@Override | boolean equals(Object obj) -
Compares this object against the specified object.
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int | compareTo(Object o) -
Compares this TimeStamp to another Object.
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int | compareTo(TimeStamp anotherTimeStamp) -
Compares two Timestamps numerically.
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protected static long | decodeNtpHexString(String s) -
Convert NTP timestamp hexstring (e.g.
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static TimeStamp | 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.
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Date | getDate() -
Convert NTP timestamp to Java Date object.
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long | getFraction() -
Returns low-order 32-bits representing the fractional seconds.
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static TimeStamp | getNtpTime(long date) -
Helper method to convert Java time to NTP timestamp object.
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long | getSeconds() -
Returns high-order 32-bits representing the seconds of this NTP timestamp.
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long | getTime() -
Convert NTP timestamp to Java standard time.
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static long | getTime(long ntpTimeValue) -
Convert 64-bit NTP timestamp to Java standard time.
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@Override | int hashCode() -
Computes a hashcode for this Timestamp.
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long | ntpValue() -
Returns the value of this Timestamp as a long value.
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static TimeStamp | parseNtpString(String s) -
Parses the string argument as a NTP hexidecimal timestamp representation string
(e.g.
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String | toDateString() -
Converts this
TimeStamp object to a String
of the form:
EEE, MMM dd yyyy HH:mm:ss.SSS
See java.text.SimpleDataFormat for code descriptions.
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protected static long | toNtpTime(long t) -
Converts Java time to 64-bit NTP time representation.
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static String | toString(long ntpTime) -
Converts 64-bit NTP timestamp value to a
String .
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String | toUTCString() -
Converts this
TimeStamp object to a String
of the form:
EEE, MMM dd yyyy HH:mm:ss.SSS UTC
See java.text.SimpleDataFormat for code descriptions.
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NTP_DATE_FORMAT
public static final String NTP_DATE_FORMAT
Default NTP date string format. E.g. Fri, Sep 12 2003 21:06:23.860.
See java.text.SimpleDateFormat
for code descriptions.
msb0baseTime
protected static final long msb0baseTime
baseline NTP time if bit-0=0 -> 7-Feb-2036 @ 06:28:16 UTC
msb1baseTime
protected static final long msb1baseTime
baseline NTP time if bit-0=1 -> 1-Jan-1900 @ 01:00:00 UTC
TimeStamp
public TimeStamp(Date d)
Constructs a newly allocated NTP timestamp object
that represents the Java Date argument.
d
- - the Date to be represented by the Timestamp object.
TimeStamp
public TimeStamp(String s)
throws NumberFormatException
Constructs a newly allocated NTP timestamp object
that represents the value represented by the string
in hexdecimal form (e.g. "c1a089bd.fc904f6d").
TimeStamp
public TimeStamp(long ntpTime)
Constructs a newly allocated NTP timestamp object
that represents the native 64-bit long argument.
String toString
public @Override String toString()
Converts this TimeStamp
object to a String
.
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
- NTP timestamp 64-bit long value as hex string with seconds
separated by fractional seconds.
boolean equals
public @Override 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 Long
object that
contains the same long
value as this object.
obj
- the object to compare with.
true
if the objects are the same;
false
otherwise.
compareTo
public int compareTo(Object o)
Compares this TimeStamp to another Object. If the Object is a TimeStamp,
this function behaves like compareTo(TimeStamp)
. Otherwise,
it throws a ClassCastException
(as TimeStamps are comparable
only to other TimeStamps).
o
- the Object
to be compared.
- the value
0
if the argument is a TimeStamp
numerically equal to this TimeStamp; a value less than
0
if the argument is a TimeStamp numerically
greater than this TimeStamp; and a value greater than
0
if the argument is a TimeStamp numerically
less than this TimeStamp.
compareTo
public int compareTo(TimeStamp anotherTimeStamp)
Compares two Timestamps numerically.
anotherTimeStamp
- - the TimeStamp
to be compared.
- the value
0
if the argument TimeStamp is equal to
this TimeStamp; a value less than 0
if this TimeStamp
is numerically less than the TimeStamp argument; and a
value greater than 0
if this TimeStamp is
numerically greater than the TimeStamp argument
(signed comparison).
decodeNtpHexString
protected static long decodeNtpHexString(String s)
throws NumberFormatException
Convert NTP timestamp hexstring (e.g. "c1a089bd.fc904f6d") to the NTP
64-bit unsigned fixed-point number.
- NTP 64-bit timestamp value.
getCurrentTime
public static TimeStamp 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.
- NTP timestamp object set to the current time.
java.lang.System.currentTimeMillis()
getDate
public Date getDate()
Convert NTP timestamp to Java Date object.
- NTP Timestamp in Java Date
getFraction
public long getFraction()
Returns low-order 32-bits representing the fractional seconds.
- fractional seconds represented by this NTP timestamp.
getNtpTime
public static TimeStamp getNtpTime(long date)
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.
date
- the milliseconds since January 1, 1970, 00:00:00 GMT.
- NTP timestamp object at the specified date.
getSeconds
public long getSeconds()
Returns high-order 32-bits representing the seconds of this NTP timestamp.
- seconds represented by this NTP timestamp.
getTime
public long getTime()
Convert NTP timestamp to Java standard time.
- NTP Timestamp in Java time
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.
- the number of milliseconds since January 1, 1970, 00:00:00 GMT
represented by this NTP timestamp value.
int hashCode
public @Override int hashCode()
Computes a hashcode for this Timestamp. The result is the exclusive
OR of the two halves of the primitive
long
value
represented by this
TimeStamp
object. That is, the hashcode
is the value of the expression:
(int)(this.ntpValue()^(this.ntpValue() >>> 32))
- a hash code value for this object.
ntpValue
public long ntpValue()
Returns the value of this Timestamp as a long value.
- the 64-bit long value represented by this object.
parseNtpString
public static TimeStamp parseNtpString(String s)
throws NumberFormatException
Parses the string argument as a NTP hexidecimal timestamp representation string
(e.g. "c1a089bd.fc904f6d").
- the Timestamp represented by the argument in hexidecimal.
toDateString
public String toDateString()
Converts this
TimeStamp
object to a
String
of the form:
EEE, MMM dd yyyy HH:mm:ss.SSS
See java.text.SimpleDataFormat for code descriptions.
- a string representation of this date.
toNtpTime
protected static long toNtpTime(long t)
Converts Java time to 64-bit NTP time representation.
- NTP timestamp representation of Java time value.
toString
public static String toString(long ntpTime)
Converts 64-bit NTP timestamp value to a String
.
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
- NTP timestamp 64-bit long value as hex string with seconds
separated by fractional seconds.
toUTCString
public String toUTCString()
Converts this
TimeStamp
object to a
String
of the form:
EEE, MMM dd yyyy HH:mm:ss.SSS UTC
See java.text.SimpleDataFormat for code descriptions.
- a string representation of this date in UTC.