Class Timestamp

All Implemented Interfaces:
Serializable, Cloneable, Comparable<Date> 
public class Timestamp
extends Date

A thin wrapper around java.util.Date that allows the JDBC API to identify this as an SQL TIMESTAMP value. It adds the ability to hold the SQL TIMESTAMP fractional seconds value, by allowing the specification of fractional seconds to a precision of nanoseconds. A Timestamp also provides formatting and parsing operations to support the JDBC escape syntax for timestamp values.

The precision of a Timestamp object is calculated to be either:

  • 19 , which is the number of characters in yyyy-mm-dd hh:mm:ss
  • 20 + s , which is the number of characters in the yyyy-mm-dd hh:mm:ss.[fff...] and s represents the scale of the given Timestamp, its fractional seconds precision.

Note: This type is a composite of a java.util.Date and a separate nanoseconds value. Only integral seconds are stored in the java.util.Date component. The fractional seconds - the nanos - are separate. The Timestamp.equals(Object) method never returns true when passed an object that isn't an instance of java.sql.Timestamp, because the nanos component of a date is unknown. As a result, the Timestamp.equals(Object) method is not symmetric with respect to the java.util.Date.equals(Object) method. Also, the hashCode method uses the underlying java.util.Date implementation and therefore does not include nanos in its computation.

Due to the differences between the Timestamp class and the java.util.Date class mentioned above, it is recommended that code not view Timestamp values generically as an instance of java.util.Date. The inheritance relationship between Timestamp and java.util.Date really denotes implementation inheritance, and not type inheritance.

Since:
1.1
See Also:
Serialized Form

Constructors

Constructor Description
Timestamp​(int year, int month, int date, int hour, int minute, int second, int nano)

Deprecated.

instead use the constructor Timestamp(long millis)

Timestamp​(long time)

Constructs a Timestamp object using a milliseconds time value.

Methods

Modifier and Type Method Description
boolean after​(Timestamp ts)

Indicates whether this Timestamp object is later than the given Timestamp object.
boolean before​(Timestamp ts)

Indicates whether this Timestamp object is earlier than the given Timestamp object.
int compareTo​(Timestamp ts)

Compares this Timestamp object to the given Timestamp object.
int compareTo​(Date o)

Compares this Timestamp object to the given Date object.
boolean equals​(Object ts)

Tests to see if this Timestamp object is equal to the given object.
boolean equals​(Timestamp ts)

Tests to see if this Timestamp object is equal to the given Timestamp object.
static Timestamp from​(Instant instant)

Obtains an instance of Timestamp from an Instant object.
int getNanos()

Gets this Timestamp object's nanos value.
long getTime()

Returns the number of milliseconds since January 1, 1970, 00:00:00 GMT represented by this Timestamp object.
int hashCode()

Returns a hash code value for this object.
void setNanos​(int n)

Sets this Timestamp object's nanos field to the given value.
void setTime​(long time)

Sets this Timestamp object to represent a point in time that is time milliseconds after January 1, 1970 00:00:00 GMT.
Instant toInstant()

Converts this Timestamp object to an Instant.
LocalDateTime toLocalDateTime()

Converts this Timestamp object to a LocalDateTime.
String toString()

Formats a timestamp in JDBC timestamp escape format.
static Timestamp valueOf​(String s)

Converts a String object in JDBC timestamp escape format to a Timestamp value.
static Timestamp valueOf​(LocalDateTime dateTime)

Obtains an instance of Timestamp from a LocalDateTime object, with the same year, month, day of month, hours, minutes, seconds and nanos date-time value as the provided LocalDateTime.

Methods declared in class java.util.Date

after, before, clone, getDate, getDay, getHours, getMinutes, getMonth, getSeconds, getTimezoneOffset, getYear, parse, setDate, setHours, setMinutes, setMonth, setSeconds, setYear, toGMTString, toLocaleString, UTC

Methods declared in class java.lang.Object

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

Constructors

Timestamp

@Deprecated(since="1.2")
public Timestamp(int year,
                 int month,
                 int date,
                 int hour,
                 int minute,
                 int second,
                 int nano)
Deprecated.
instead use the constructor Timestamp(long millis)

Constructs a Timestamp object initialized with the given values.

Parameters:
year - the year minus 1900
month - 0 to 11
date - 1 to 31
hour - 0 to 23
minute - 0 to 59
second - 0 to 59
nano - 0 to 999,999,999
Throws:
IllegalArgumentException - if the nano argument is out of bounds

Timestamp

public Timestamp(long time)

Constructs a Timestamp object using a milliseconds time value. The integral seconds are stored in the underlying date value; the fractional seconds are stored in the nanos field of the Timestamp object.

Parameters:
time - milliseconds since January 1, 1970, 00:00:00 GMT. A negative number is the number of milliseconds before January 1, 1970, 00:00:00 GMT.
See Also:
Calendar

Methods

setTime

public void setTime(long time)

Sets this Timestamp object to represent a point in time that is time milliseconds after January 1, 1970 00:00:00 GMT.

Overrides:
setTime in class Date
Parameters:
time - the number of milliseconds.
See Also:
getTime(), Timestamp(long time), Calendar

getTime

public long getTime()

Returns the number of milliseconds since January 1, 1970, 00:00:00 GMT represented by this Timestamp object.

Overrides:
getTime in class Date
Returns:
the number of milliseconds since January 1, 1970, 00:00:00 GMT represented by this date.
See Also:
setTime(long)

valueOf

public static Timestamp valueOf(String s)

Converts a String object in JDBC timestamp escape format to a Timestamp value.

Parameters:
s - timestamp in format yyyy-[m]m-[d]d hh:mm:ss[.f...]. The fractional seconds may be omitted. The leading zero for mm and dd may also be omitted.
Returns:
corresponding Timestamp value
Throws:
IllegalArgumentException - if the given argument does not have the format yyyy-[m]m-[d]d hh:mm:ss[.f...]

toString

public String toString()

Formats a timestamp in JDBC timestamp escape format. yyyy-mm-dd hh:mm:ss.fffffffff, where fffffffff indicates nanoseconds.

Overrides:
toString in class Date
Returns:
a String object in yyyy-mm-dd hh:mm:ss.fffffffff format
See Also:
Date.toLocaleString(), Date.toGMTString()

getNanos

public int getNanos()

Gets this Timestamp object's nanos value.

Returns:
this Timestamp object's fractional seconds component
See Also:
setNanos(int)

setNanos

public void setNanos(int n)

Sets this Timestamp object's nanos field to the given value.

Parameters:
n - the new fractional seconds component
Throws:
IllegalArgumentException - if the given argument is greater than 999999999 or less than 0
See Also:
getNanos()

equals

public boolean equals(Timestamp ts)

Tests to see if this Timestamp object is equal to the given Timestamp object.

Parameters:
ts - the Timestamp value to compare with
Returns:
true if the given Timestamp object is equal to this Timestamp object; false otherwise

equals

public boolean equals(Object ts)

Tests to see if this Timestamp object is equal to the given object. This version of the method equals has been added to fix the incorrect signature of Timestamp.equals(Timestamp) and to preserve backward compatibility with existing class files. Note: This method is not symmetric with respect to the equals(Object) method in the base class.

Overrides:
equals in class Date
Parameters:
ts - the Object value to compare with
Returns:
true if the given Object is an instance of a Timestamp that is equal to this Timestamp object; false otherwise
See Also:
Date.getTime()

before

public boolean before(Timestamp ts)

Indicates whether this Timestamp object is earlier than the given Timestamp object.

Parameters:
ts - the Timestamp value to compare with
Returns:
true if this Timestamp object is earlier; false otherwise

after

public boolean after(Timestamp ts)

Indicates whether this Timestamp object is later than the given Timestamp object.

Parameters:
ts - the Timestamp value to compare with
Returns:
true if this Timestamp object is later; false otherwise

compareTo

public int compareTo(Timestamp ts)

Compares this Timestamp object to the given Timestamp object.

Parameters:
ts - the Timestamp object to be compared to this Timestamp object
Returns:
the value 0 if the two Timestamp objects are equal; a value less than 0 if this Timestamp object is before the given argument; and a value greater than 0 if this Timestamp object is after the given argument.
Since:
1.4

compareTo

public int compareTo(Date o)

Compares this Timestamp object to the given Date object.

Specified by:
compareTo in interface Comparable<Date>
Overrides:
compareTo in class Date
Parameters:
o - the Date to be compared to this Timestamp object
Returns:
the value 0 if this Timestamp object and the given object are equal; a value less than 0 if this Timestamp object is before the given argument; and a value greater than 0 if this Timestamp object is after the given argument.
Since:
1.5

hashCode

public int hashCode()

Returns a hash code value for this object. The result is the exclusive OR of the two halves of the primitive long value returned by the Date.getTime() method. That is, the hash code is the value of the expression: 

(int)(this.getTime()^(this.getTime() >>> 32))
The hashCode method uses the underlying java.util.Date implementation and therefore does not include nanos in its computation.

Overrides:
hashCode in class Date
Returns:
a hash code value for this object.
See Also:
Object.equals(java.lang.Object), System.identityHashCode(java.lang.Object)

valueOf

public static Timestamp valueOf(LocalDateTime dateTime)

Obtains an instance of Timestamp from a LocalDateTime object, with the same year, month, day of month, hours, minutes, seconds and nanos date-time value as the provided LocalDateTime.

The provided LocalDateTime is interpreted as the local date-time in the local time zone.

Parameters:
dateTime - a LocalDateTime to convert
Returns:
a Timestamp object
Throws:
NullPointerException - if dateTime is null.
Since:
1.8

toLocalDateTime

public LocalDateTime toLocalDateTime()

Converts this Timestamp object to a LocalDateTime.

The conversion creates a LocalDateTime that represents the same year, month, day of month, hours, minutes, seconds and nanos date-time value as this Timestamp in the local time zone.

Returns:
a LocalDateTime object representing the same date-time value
Since:
1.8

from

public static Timestamp from(Instant instant)

Obtains an instance of Timestamp from an Instant object.

Instant can store points on the time-line further in the future and further in the past than Date. In this scenario, this method will throw an exception.

Parameters:
instant - the instant to convert
Returns:
an Timestamp representing the same point on the time-line as the provided instant
Throws:
NullPointerException - if instant is null.
IllegalArgumentException - if the instant is too large to represent as a Timestamp
Since:
1.8

toInstant

public Instant toInstant()

Converts this Timestamp object to an Instant.

The conversion creates an Instant that represents the same point on the time-line as this Timestamp.

Overrides:
toInstant in class Date
Returns:
an instant representing the same point on the time-line
Since:
1.8

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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
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https://docs.oracle.com/en/java/javase/11/docs/api/java.sql/java/sql/Timestamp.html