And class java util date in java util

Uses of Class
java.util.Date

Provides classes and interfaces for parsing and managing certificates, certificate revocation lists (CRLs), and certification paths.

Provides the API for accessing and processing data stored in a data source (usually a relational database) using the Java programming language.

Provides classes and interfaces for handling text, dates, numbers, and messages in a manner independent of natural languages.

Contains the collections framework, some internationalization support classes, a service loader, properties, random number generation, string parsing and scanning classes, base64 encoding and decoding, a bit array, and several miscellaneous utility classes.

Interfaces and classes providing a framework for locking and waiting for conditions that is distinct from built-in synchronization and monitors.

Provides classes and interfaces that describe the types of Java Print Service attributes and how they can be collected into attribute sets.

Provides a set of «lightweight» (all-Java language) components that, to the maximum degree possible, work the same on all platforms.

Uses of Date in java.security

Uses of Date in java.security.cert

Returns the invalidity date, as specified in the Invalidity Date extension of this CertificateRevokedException .

Constructs a CertificateRevokedException with the specified revocation date, reason code, authority name, and map of extensions.

Uses of Date in java.sql

A thin wrapper around the java.util.Date class that allows the JDBC API to identify this as an SQL TIME value.

A thin wrapper around java.util.Date that allows the JDBC API to identify this as an SQL TIMESTAMP value.

Uses of Date in java.text

Sets the 100-year period 2-digit years will be interpreted as being in to begin on the date the user specifies.

Uses of Date in java.util

Schedules the specified task for repeated fixed-delay execution, beginning at the specified time.

Uses of Date in java.util.concurrent.locks

Causes the current thread to wait until it is signalled or interrupted, or the specified deadline elapses.

Uses of Date in javax.management.openmbean

Uses of Date in javax.management.timer

Creates a new timer notification with the specified type , message and userData and inserts it into the list of notifications with a given date and a null period and number of occurrences.

Creates a new timer notification with the specified type , message and userData and inserts it into the list of notifications with a given date and period and a null number of occurrences.

Timer. addNotification (String type, String message, Object userData, Date date, long period, long nbOccurences)

Creates a new timer notification with the specified type , message and userData and inserts it into the list of notifications with a given date, period and number of occurrences.

Timer. addNotification (String type, String message, Object userData, Date date, long period, long nbOccurences, boolean fixedRate)

Creates a new timer notification with the specified type , message and userData and inserts it into the list of notifications with a given date, period and number of occurrences.

Creates a new timer notification with the specified type , message and userData and inserts it into the list of notifications with a given date and a null period and number of occurrences.

Creates a new timer notification with the specified type , message and userData and inserts it into the list of notifications with a given date and period and a null number of occurrences.

TimerMBean. addNotification (String type, String message, Object userData, Date date, long period, long nbOccurences)

Creates a new timer notification with the specified type , message and userData and inserts it into the list of notifications with a given date, period and number of occurrences.

TimerMBean. addNotification (String type, String message, Object userData, Date date, long period, long nbOccurences, boolean fixedRate)

Creates a new timer notification with the specified type , message and userData and inserts it into the list of notifications with a given date, period and number of occurrences.

Uses of Date in javax.print.attribute

Uses of Date in javax.print.attribute.standard

Uses of Date in javax.security.auth.kerberos

KerberosTicket (byte[] asn1Encoding, KerberosPrincipal client, KerberosPrincipal server, byte[] sessionKey, int keyType, boolean[] flags, Date authTime, Date startTime, Date endTime, Date renewTill, InetAddress[] clientAddresses)

Constructs a KerberosTicket using credentials information that a client either receives from a KDC or reads from a cache.

Uses of Date in javax.security.cert

Uses of Date in javax.swing

Returns a RowFilter that includes entries that have at least one Date value meeting the specified criteria.

Uses of Date in javax.xml.datatype

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Class Date

Prior to JDK 1.1, the class Date had two additional functions. It allowed the interpretation of dates as year, month, day, hour, minute, and second values. It also allowed the formatting and parsing of date strings. Unfortunately, the API for these functions was not amenable to internationalization. As of JDK 1.1, the Calendar class should be used to convert between dates and time fields and the DateFormat class should be used to format and parse date strings. The corresponding methods in Date are deprecated.

Although the Date class is intended to reflect coordinated universal time (UTC), it may not do so exactly, depending on the host environment of the Java Virtual Machine. Nearly all modern operating systems assume that 1 day = 24 × 60 × 60 = 86400 seconds in all cases. In UTC, however, about once every year or two there is an extra second, called a «leap second.» The leap second is always added as the last second of the day, and always on December 31 or June 30. For example, the last minute of the year 1995 was 61 seconds long, thanks to an added leap second. Most computer clocks are not accurate enough to be able to reflect the leap-second distinction.

Some computer standards are defined in terms of Greenwich mean time (GMT), which is equivalent to universal time (UT). GMT is the «civil» name for the standard; UT is the «scientific» name for the same standard. The distinction between UTC and UT is that UTC is based on an atomic clock and UT is based on astronomical observations, which for all practical purposes is an invisibly fine hair to split. Because the earth’s rotation is not uniform (it slows down and speeds up in complicated ways), UT does not always flow uniformly. Leap seconds are introduced as needed into UTC so as to keep UTC within 0.9 seconds of UT1, which is a version of UT with certain corrections applied. There are other time and date systems as well; for example, the time scale used by the satellite-based global positioning system (GPS) is synchronized to UTC but is not adjusted for leap seconds. An interesting source of further information is the United States Naval Observatory (USNO):

and the material regarding «Systems of Time» at:

which has descriptions of various different time systems including UT, UT1, and UTC.

• A year y is represented by the integer y — 1900 .
• A month is represented by an integer from 0 to 11; 0 is January, 1 is February, and so forth; thus 11 is December.
• A date (day of month) is represented by an integer from 1 to 31 in the usual manner.
• An hour is represented by an integer from 0 to 23. Thus, the hour from midnight to 1 a.m. is hour 0, and the hour from noon to 1 p.m. is hour 12.
• A minute is represented by an integer from 0 to 59 in the usual manner.
• A second is represented by an integer from 0 to 61; the values 60 and 61 occur only for leap seconds and even then only in Java implementations that actually track leap seconds correctly. Because of the manner in which leap seconds are currently introduced, it is extremely unlikely that two leap seconds will occur in the same minute, but this specification follows the date and time conventions for ISO C.

In all cases, arguments given to methods for these purposes need not fall within the indicated ranges; for example, a date may be specified as January 32 and is interpreted as meaning February 1.

Constructor Summary

Allocates a Date object and initializes it so that it represents the time at which it was allocated, measured to the nearest millisecond.

As of JDK version 1.1, replaced by Calendar.set(year + 1900, month, date) or GregorianCalendar(year + 1900, month, date) .

As of JDK version 1.1, replaced by Calendar.set(year + 1900, month, date, hrs, min) or GregorianCalendar(year + 1900, month, date, hrs, min) .

As of JDK version 1.1, replaced by Calendar.set(year + 1900, month, date, hrs, min, sec) or GregorianCalendar(year + 1900, month, date, hrs, min, sec) .

Allocates a Date object and initializes it to represent the specified number of milliseconds since the standard base time known as «the epoch», namely January 1, 1970, 00:00:00 GMT.

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Difference between Date class in Package java.util & Package java.sql

In java, both the java.util and the java.sql package contain a Date class, So what is the difference between them? If one Date class is present in Java then what is the need of another Date class?

5 Answers 5

A thin wrapper around a millisecond value that allows JDBC to identify this as an SQL DATE value. A milliseconds value represents the number of milliseconds that have passed since January 1, 1970 00:00:00.000 GMT.

To conform with the definition of SQL DATE, the millisecond values wrapped by a java.sql.Date instance must be ‘normalized’ by setting the hours, minutes, seconds, and milliseconds to zero in the particular time zone with which the instance is associated.

Explanation: A java.util.Date represents date and time of day, a java.sql.Date only represents a date (the complement of java.sql.Date is java.sql.Time , which only represents a time of day, but also extends java.util.Date ).

These answers seem to be partially outdated.

I just read a little API Code (Java Version 1.8.0_91) and found this in java.sql.Date :

/** * Creates a date which corresponds to the day determined by the supplied * milliseconds time value . * * @param theDate * a time value in milliseconds since the epoch - January 1 1970 * 00:00:00 GMT. The time value (hours, minutes, seconds, * milliseconds) stored in the object is adjusted to * correspond to 00:00:00 GMT on the day determined by the supplied * time value. */ public Date(long theDate) < super(normalizeTime(theDate)); >/* * Private method which normalizes a Time value, removing all low * significance digits corresponding to milliseconds, seconds, minutes and * hours, so that the returned Time value corresponds to 00:00:00 GMT on a * particular day. */ private static long normalizeTime(long theTime)

The method for normalizing the time is still there and even the comment says that the time will be normalized to 00:00:00 GMT but it does nothing. For some reason they removed the normalization, wich means, that a java.sql.Date contains just like a java.util.Date just the number of milliseconds since 1.1.1970. So there is a time component but it is not displayed externally.

java.util.Date utilDate = new java.util.Date(); java.sql.Date sqlDate = new java.sql.Date(Calendar.getInstance().getTimeInMillis()) System.out.println(utilDate); System.out.println(sqlDate); 

Thu Jun 02 13:17:35 CEST 2016 2016-06-02 

So be careful with sql dates and do not handle them like they would just contain a Date and no time information. For example:

java.sql.Date sqlDate1 = new java.sql.Date(Calendar.getInstance().getTimeInMillis()); java.sql.Date sqlDate2 = new java.sql.Date(Calendar.getInstance().getTimeInMillis()); System.out.println(sqlDate1); System.out.println(sqlDate2); System.out.println(sqlDate1.equals(sqlDate2)); System.out.println(sqlDate1.toString().equals(sqlDate2.toString())); 

2016-06-02 2016-06-02 false true 

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