System date format java

System date format java

DateFormat is an abstract class for date/time formatting subclasses which formats and parses dates or time in a language-independent manner. The date/time formatting subclass, such as SimpleDateFormat , allows for formatting (i.e., date → text), parsing (text → date), and normalization. The date is represented as a Date object or as the milliseconds since January 1, 1970, 00:00:00 GMT. DateFormat provides many class methods for obtaining default date/time formatters based on the default or a given locale and a number of formatting styles. The formatting styles include FULL , LONG , MEDIUM , and SHORT . More detail and examples of using these styles are provided in the method descriptions. DateFormat helps you to format and parse dates for any locale. Your code can be completely independent of the locale conventions for months, days of the week, or even the calendar format: lunar vs. solar. To format a date for the current Locale, use one of the static factory methods:

 myString = DateFormat.getDateInstance().format(myDate); 

If you are formatting multiple dates, it is more efficient to get the format and use it multiple times so that the system doesn’t have to fetch the information about the local language and country conventions multiple times.

 DateFormat df = DateFormat.getDateInstance(); for (int i = 0; i

 DateFormat df = DateFormat.getDateInstance(DateFormat.LONG, Locale.FRANCE); 

• SHORT is completely numeric, such as 12.13.52 or 3:30pm
• MEDIUM is longer, such as Jan 12, 1952
• LONG is longer, such as January 12, 1952 or 3:30:32pm
• FULL is pretty completely specified, such as Tuesday, April 12, 1952 AD or 3:30:42pm PST .

• progressively parse through pieces of a string.
• align any particular field, or find out where it is for selection on the screen.

Synchronization

Date formats are not synchronized. It is recommended to create separate format instances for each thread. If multiple threads access a format concurrently, it must be synchronized externally.

Nested Class Summary

Defines constants that are used as attribute keys in the AttributedCharacterIterator returned from DateFormat.formatToCharacterIterator and as field identifiers in FieldPosition .

Field Summary

Constructor Summary

Method Summary

Returns an array of all locales for which the get*Instance methods of this class can return localized instances.

Gets the date/time formatter with the given date and time formatting styles for the default FORMAT locale.

Methods inherited from class java.text.Format

Methods inherited from class java.lang.Object

Field Detail

calendar

The Calendar instance used for calculating the date-time fields and the instant of time. This field is used for both formatting and parsing. Subclasses should initialize this field to a Calendar appropriate for the Locale associated with this DateFormat .

numberFormat

The number formatter that DateFormat uses to format numbers in dates and times. Subclasses should initialize this to a number format appropriate for the locale associated with this DateFormat .

ERA_FIELD

public static final int ERA_FIELD

YEAR_FIELD

public static final int YEAR_FIELD

MONTH_FIELD

public static final int MONTH_FIELD

DATE_FIELD

public static final int DATE_FIELD

HOUR_OF_DAY1_FIELD

public static final int HOUR_OF_DAY1_FIELD

Useful constant for one-based HOUR_OF_DAY field alignment. Used in FieldPosition of date/time formatting. HOUR_OF_DAY1_FIELD is used for the one-based 24-hour clock. For example, 23:59 + 01:00 results in 24:59.

HOUR_OF_DAY0_FIELD

public static final int HOUR_OF_DAY0_FIELD

Useful constant for zero-based HOUR_OF_DAY field alignment. Used in FieldPosition of date/time formatting. HOUR_OF_DAY0_FIELD is used for the zero-based 24-hour clock. For example, 23:59 + 01:00 results in 00:59.

MINUTE_FIELD

public static final int MINUTE_FIELD

SECOND_FIELD

public static final int SECOND_FIELD

MILLISECOND_FIELD

public static final int MILLISECOND_FIELD

DAY_OF_WEEK_FIELD

public static final int DAY_OF_WEEK_FIELD

DAY_OF_YEAR_FIELD

public static final int DAY_OF_YEAR_FIELD

DAY_OF_WEEK_IN_MONTH_FIELD

public static final int DAY_OF_WEEK_IN_MONTH_FIELD

Useful constant for DAY_OF_WEEK_IN_MONTH field alignment. Used in FieldPosition of date/time formatting.

WEEK_OF_YEAR_FIELD

public static final int WEEK_OF_YEAR_FIELD

WEEK_OF_MONTH_FIELD

public static final int WEEK_OF_MONTH_FIELD

AM_PM_FIELD

public static final int AM_PM_FIELD

HOUR1_FIELD

public static final int HOUR1_FIELD

Useful constant for one-based HOUR field alignment. Used in FieldPosition of date/time formatting. HOUR1_FIELD is used for the one-based 12-hour clock. For example, 11:30 PM + 1 hour results in 12:30 AM.

HOUR0_FIELD

public static final int HOUR0_FIELD

Useful constant for zero-based HOUR field alignment. Used in FieldPosition of date/time formatting. HOUR0_FIELD is used for the zero-based 12-hour clock. For example, 11:30 PM + 1 hour results in 00:30 AM.

TIMEZONE_FIELD

public static final int TIMEZONE_FIELD

FULL

public static final int FULL

LONG

public static final int LONG

MEDIUM

public static final int MEDIUM

SHORT

public static final int SHORT

DEFAULT

public static final int DEFAULT

Constructor Detail

DateFormat

Method Detail

format

public final StringBuffer format(Object obj, StringBuffer toAppendTo, FieldPosition fieldPosition)

Overrides Format. Formats a time object into a time string. Examples of time objects are a time value expressed in milliseconds and a Date object.

format

public abstract StringBuffer format(Date date, StringBuffer toAppendTo, FieldPosition fieldPosition)

format

parse

public Date parse(String source) throws ParseException

Parses text from the beginning of the given string to produce a date. The method may not use the entire text of the given string. See the parse(String, ParsePosition) method for more information on date parsing.

parse

public abstract Date parse(String source, ParsePosition pos)

Parse a date/time string according to the given parse position. For example, a time text «07/10/96 4:5 PM, PDT» will be parsed into a Date that is equivalent to Date(837039900000L) . By default, parsing is lenient: If the input is not in the form used by this object’s format method but can still be parsed as a date, then the parse succeeds. Clients may insist on strict adherence to the format by calling setLenient(false) . This parsing operation uses the calendar to produce a Date . As a result, the calendar ‘s date-time fields and the TimeZone value may have been overwritten, depending on subclass implementations. Any TimeZone value that has previously been set by a call to setTimeZone may need to be restored for further operations.

parseObject

public Object parseObject(String source, ParsePosition pos)

Parses text from a string to produce a Date . The method attempts to parse text starting at the index given by pos . If parsing succeeds, then the index of pos is updated to the index after the last character used (parsing does not necessarily use all characters up to the end of the string), and the parsed date is returned. The updated pos can be used to indicate the starting point for the next call to this method. If an error occurs, then the index of pos is not changed, the error index of pos is set to the index of the character where the error occurred, and null is returned. See the parse(String, ParsePosition) method for more information on date parsing.

getTimeInstance

Gets the time formatter with the default formatting style for the default FORMAT locale. This is equivalent to calling getTimeInstance(DEFAULT, Locale.getDefault(Locale.Category.FORMAT)) .

getTimeInstance

Gets the time formatter with the given formatting style for the default FORMAT locale. This is equivalent to calling getTimeInstance(style, Locale.getDefault(Locale.Category.FORMAT)) .

getTimeInstance

public static final DateFormat getTimeInstance(int style, Locale aLocale)

getDateInstance

Gets the date formatter with the default formatting style for the default FORMAT locale. This is equivalent to calling getDateInstance(DEFAULT, Locale.getDefault(Locale.Category.FORMAT)) .

getDateInstance

Gets the date formatter with the given formatting style for the default FORMAT locale. This is equivalent to calling getDateInstance(style, Locale.getDefault(Locale.Category.FORMAT)) .

getDateInstance

public static final DateFormat getDateInstance(int style, Locale aLocale)

getDateTimeInstance

Gets the date/time formatter with the default formatting style for the default FORMAT locale. This is equivalent to calling getDateTimeInstance(DEFAULT, DEFAULT, Locale.getDefault(Locale.Category.FORMAT)) .

getDateTimeInstance

public static final DateFormat getDateTimeInstance(int dateStyle, int timeStyle)

Gets the date/time formatter with the given date and time formatting styles for the default FORMAT locale. This is equivalent to calling getDateTimeInstance(dateStyle, timeStyle, Locale.getDefault(Locale.Category.FORMAT)) .

getDateTimeInstance

public static final DateFormat getDateTimeInstance(int dateStyle, int timeStyle, Locale aLocale)

getInstance

getAvailableLocales

Returns an array of all locales for which the get*Instance methods of this class can return localized instances. The returned array represents the union of locales supported by the Java runtime and by installed DateFormatProvider implementations. It must contain at least a Locale instance equal to Locale.US .

setCalendar

Set the calendar to be used by this date format. Initially, the default calendar for the specified or default locale is used. Any TimeZone and leniency values that have previously been set are overwritten by newCalendar ‘s values.

getCalendar

setNumberFormat

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