java.sql

Class Timestamp

java.lang.Object

java.util.Date

java.sql.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.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and 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.

Method Summary

Methods

Modifier and Type	Method and 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(Date o) Compares this Timestamp object to the given Date object.
int	compareTo(Timestamp ts) Compares this Timestamp object to the given Timestamp 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.
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.
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.

Methods inherited from 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 inherited from class java.lang.Object

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

Constructor Detail

Timestamp

@Deprecated
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

Method Detail

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 ffffffffff 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)