Date object or
* as the milliseconds since January 1, 1970, 00:00:00 GMT.
*
* {@code 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 {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, and {@link #SHORT}. More * detail and examples of using these styles are provided in the method * descriptions. * *
{@code 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 < myDate.length; ++i) {
* output.println(df.format(myDate[i]) + "; ");
* }
*
* To format a date for a different Locale, specify it in the * call to {@link #getDateInstance(int, Locale) getDateInstance()}. *
* DateFormat df = DateFormat.getDateInstance(DateFormat.LONG, Locale.FRANCE); **
You can use a DateFormat to parse also. *
* myDate = df.parse(myString); **
Use {@code getDateInstance} to get the normal date format for that country. * There are other static factory methods available. * Use {@code getTimeInstance} to get the time format for that country. * Use {@code getDateTimeInstance} to get a date and time format. You can pass in * different options to these factory methods to control the length of the * result; from {@link #SHORT} to {@link #MEDIUM} to {@link #LONG} to {@link #FULL}. The exact result depends * on the locale, but generally: *
You can also set the time zone on the format if you wish. * If you want even more control over the format or parsing, * (or want to give your users more control), * you can try casting the {@code DateFormat} you get from the factory methods * to a {@link SimpleDateFormat}. This will work for the majority * of countries; just remember to put it in a {@code try} block in case you * encounter an unusual one. * *
You can also use forms of the parse and format methods with * {@link ParsePosition} and {@link FieldPosition} to * allow you to *
* 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. * * @see Format * @see NumberFormat * @see SimpleDateFormat * @see java.util.Calendar * @see java.util.GregorianCalendar * @see java.util.TimeZone * @author Mark Davis, Chen-Lieh Huang, Alan Liu */ public abstract class DateFormat extends Format { /** * The {@link 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 {@link Calendar}
* appropriate for the {@link Locale} associated with this
* DateFormat.
* @serial
*/
protected Calendar calendar;
/**
* 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.
* @serial
*/
protected NumberFormat numberFormat;
/**
* Useful constant for ERA field alignment.
* Used in FieldPosition of date/time formatting.
*/
public final static int ERA_FIELD = 0;
/**
* Useful constant for YEAR field alignment.
* Used in FieldPosition of date/time formatting.
*/
public final static int YEAR_FIELD = 1;
/**
* Useful constant for MONTH field alignment.
* Used in FieldPosition of date/time formatting.
*/
public final static int MONTH_FIELD = 2;
/**
* Useful constant for DATE field alignment.
* Used in FieldPosition of date/time formatting.
*/
public final static int DATE_FIELD = 3;
/**
* 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.
*/
public final static int HOUR_OF_DAY1_FIELD = 4;
/**
* 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.
*/
public final static int HOUR_OF_DAY0_FIELD = 5;
/**
* Useful constant for MINUTE field alignment.
* Used in FieldPosition of date/time formatting.
*/
public final static int MINUTE_FIELD = 6;
/**
* Useful constant for SECOND field alignment.
* Used in FieldPosition of date/time formatting.
*/
public final static int SECOND_FIELD = 7;
/**
* Useful constant for MILLISECOND field alignment.
* Used in FieldPosition of date/time formatting.
*/
public final static int MILLISECOND_FIELD = 8;
/**
* Useful constant for DAY_OF_WEEK field alignment.
* Used in FieldPosition of date/time formatting.
*/
public final static int DAY_OF_WEEK_FIELD = 9;
/**
* Useful constant for DAY_OF_YEAR field alignment.
* Used in FieldPosition of date/time formatting.
*/
public final static int DAY_OF_YEAR_FIELD = 10;
/**
* Useful constant for DAY_OF_WEEK_IN_MONTH field alignment.
* Used in FieldPosition of date/time formatting.
*/
public final static int DAY_OF_WEEK_IN_MONTH_FIELD = 11;
/**
* Useful constant for WEEK_OF_YEAR field alignment.
* Used in FieldPosition of date/time formatting.
*/
public final static int WEEK_OF_YEAR_FIELD = 12;
/**
* Useful constant for WEEK_OF_MONTH field alignment.
* Used in FieldPosition of date/time formatting.
*/
public final static int WEEK_OF_MONTH_FIELD = 13;
/**
* Useful constant for AM_PM field alignment.
* Used in FieldPosition of date/time formatting.
*/
public final static int AM_PM_FIELD = 14;
/**
* 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.
*/
public final static int HOUR1_FIELD = 15;
/**
* 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.
*/
public final static int HOUR0_FIELD = 16;
/**
* Useful constant for TIMEZONE field alignment.
* Used in FieldPosition of date/time formatting.
*/
public final static int TIMEZONE_FIELD = 17;
// Proclaim serial compatibility with 1.1 FCS
private static final long serialVersionUID = 7218322306649953788L;
/**
* 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.
* @param obj must be a Number or a Date.
* @param toAppendTo the string buffer for the returning time string.
* @return the string buffer passed in as toAppendTo, with formatted text appended.
* @param fieldPosition keeps track of the position of the field
* within the returned string.
* On input: an alignment field,
* if desired. On output: the offsets of the alignment field. For
* example, given a time text "1996.07.10 AD at 15:08:56 PDT",
* if the given fieldPosition is DateFormat.YEAR_FIELD, the
* begin index and end index of fieldPosition will be set to
* 0 and 4, respectively.
* Notice that if the same time field appears
* more than once in a pattern, the fieldPosition will be set for the first
* occurrence of that time field. For instance, formatting a Date to
* the time string "1 PM PDT (Pacific Daylight Time)" using the pattern
* "h a z (zzzz)" and the alignment field DateFormat.TIMEZONE_FIELD,
* the begin index and end index of fieldPosition will be set to
* 5 and 8, respectively, for the first occurrence of the timezone
* pattern character 'z'.
* @see java.text.Format
*/
public final StringBuffer format(Object obj, StringBuffer toAppendTo,
FieldPosition fieldPosition)
{
if (obj instanceof Date)
return format( (Date)obj, toAppendTo, fieldPosition );
else if (obj instanceof Number)
return format( new Date(((Number)obj).longValue()),
toAppendTo, fieldPosition );
else
throw new IllegalArgumentException("Cannot format given Object as a Date");
}
/**
* Formats a Date into a date/time string.
* @param date a Date to be formatted into a date/time string.
* @param toAppendTo the string buffer for the returning date/time string.
* @param fieldPosition keeps track of the position of the field
* within the returned string.
* On input: an alignment field,
* if desired. On output: the offsets of the alignment field. For
* example, given a time text "1996.07.10 AD at 15:08:56 PDT",
* if the given fieldPosition is DateFormat.YEAR_FIELD, the
* begin index and end index of fieldPosition will be set to
* 0 and 4, respectively.
* Notice that if the same time field appears
* more than once in a pattern, the fieldPosition will be set for the first
* occurrence of that time field. For instance, formatting a Date to
* the time string "1 PM PDT (Pacific Daylight Time)" using the pattern
* "h a z (zzzz)" and the alignment field DateFormat.TIMEZONE_FIELD,
* the begin index and end index of fieldPosition will be set to
* 5 and 8, respectively, for the first occurrence of the timezone
* pattern character 'z'.
* @return the string buffer passed in as toAppendTo, with formatted text appended.
*/
public abstract StringBuffer format(Date date, StringBuffer toAppendTo,
FieldPosition fieldPosition);
/**
* Formats a Date into a date/time string.
* @param date the time value to be formatted into a time string.
* @return the formatted time string.
*/
public final String format(Date date)
{
return format(date, new StringBuffer(),
DontCareFieldPosition.INSTANCE).toString();
}
/**
* 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 {@link #parse(String, ParsePosition)} method for more information
* on date parsing.
*
* @param source A String whose beginning should be parsed.
* @return A Date parsed from the string.
* @exception ParseException if the beginning of the specified string
* cannot be parsed.
*/
public Date parse(String source) throws ParseException
{
ParsePosition pos = new ParsePosition(0);
Date result = parse(source, pos);
if (pos.index == 0)
throw new ParseException("Unparseable date: \"" + source + "\"" ,
pos.errorIndex);
return result;
}
/**
* Parse a date/time string according to the given parse position. For
* example, a time text {@code "07/10/96 4:5 PM, PDT"} will be parsed into a {@code Date}
* that is equivalent to {@code 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 {@link #setLenient(boolean) setLenient(false)}. * *
This parsing operation uses the {@link #calendar} to produce
* a {@code Date}. As a result, the {@code calendar}'s date-time
* fields and the {@code TimeZone} value may have been
* overwritten, depending on subclass implementations. Any {@code
* TimeZone} value that has previously been set by a call to
* {@link #setTimeZone(java.util.TimeZone) setTimeZone} may need
* to be restored for further operations.
*
* @param source The date/time string to be parsed
*
* @param pos On input, the position at which to start parsing; on
* output, the position at which parsing terminated, or the
* start position if the parse failed.
*
* @return A {@code Date}, or {@code null} if the input could not be parsed
*/
public abstract Date parse(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 {@link #parse(String, ParsePosition)} method for more information
* on date parsing.
*
* @param source A String, part of which should be parsed.
* @param pos A ParsePosition object with index and error
* index information as described above.
* @return A Date parsed from the string. In case of
* error, returns null.
* @exception NullPointerException if pos is null.
*/
public Object parseObject(String source, ParsePosition pos) {
return parse(source, pos);
}
/**
* Constant for full style pattern.
*/
public static final int FULL = 0;
/**
* Constant for long style pattern.
*/
public static final int LONG = 1;
/**
* Constant for medium style pattern.
*/
public static final int MEDIUM = 2;
/**
* Constant for short style pattern.
*/
public static final int SHORT = 3;
/**
* Constant for default style pattern. Its value is MEDIUM.
*/
public static final int DEFAULT = MEDIUM;
/**
* Gets the time formatter with the default formatting style
* for the default locale.
* @return a time formatter.
*/
public final static DateFormat getTimeInstance()
{
return get(DEFAULT, 0, 1, Locale.getDefault(Locale.Category.FORMAT));
}
/**
* Gets the time formatter with the given formatting style
* for the default locale.
* @param style the given formatting style. For example,
* SHORT for "h:mm a" in the US locale.
* @return a time formatter.
*/
public final static DateFormat getTimeInstance(int style)
{
return get(style, 0, 1, Locale.getDefault(Locale.Category.FORMAT));
}
/**
* Gets the time formatter with the given formatting style
* for the given locale.
* @param style the given formatting style. For example,
* SHORT for "h:mm a" in the US locale.
* @param aLocale the given locale.
* @return a time formatter.
*/
public final static DateFormat getTimeInstance(int style,
Locale aLocale)
{
return get(style, 0, 1, aLocale);
}
/**
* Gets the date formatter with the default formatting style
* for the default locale.
* @return a date formatter.
*/
public final static DateFormat getDateInstance()
{
return get(0, DEFAULT, 2, Locale.getDefault(Locale.Category.FORMAT));
}
/**
* Gets the date formatter with the given formatting style
* for the default locale.
* @param style the given formatting style. For example,
* SHORT for "M/d/yy" in the US locale.
* @return a date formatter.
*/
public final static DateFormat getDateInstance(int style)
{
return get(0, style, 2, Locale.getDefault(Locale.Category.FORMAT));
}
/**
* Gets the date formatter with the given formatting style
* for the given locale.
* @param style the given formatting style. For example,
* SHORT for "M/d/yy" in the US locale.
* @param aLocale the given locale.
* @return a date formatter.
*/
public final static DateFormat getDateInstance(int style,
Locale aLocale)
{
return get(0, style, 2, aLocale);
}
/**
* Gets the date/time formatter with the default formatting style
* for the default locale.
* @return a date/time formatter.
*/
public final static DateFormat getDateTimeInstance()
{
return get(DEFAULT, DEFAULT, 3, Locale.getDefault(Locale.Category.FORMAT));
}
/**
* Gets the date/time formatter with the given date and time
* formatting styles for the default locale.
* @param dateStyle the given date formatting style. For example,
* SHORT for "M/d/yy" in the US locale.
* @param timeStyle the given time formatting style. For example,
* SHORT for "h:mm a" in the US locale.
* @return a date/time formatter.
*/
public final static DateFormat getDateTimeInstance(int dateStyle,
int timeStyle)
{
return get(timeStyle, dateStyle, 3, Locale.getDefault(Locale.Category.FORMAT));
}
/**
* Gets the date/time formatter with the given formatting styles
* for the given locale.
* @param dateStyle the given date formatting style.
* @param timeStyle the given time formatting style.
* @param aLocale the given locale.
* @return a date/time formatter.
*/
public final static DateFormat
getDateTimeInstance(int dateStyle, int timeStyle, Locale aLocale)
{
return get(timeStyle, dateStyle, 3, aLocale);
}
/**
* Get a default date/time formatter that uses the SHORT style for both the
* date and the time.
*/
public final static DateFormat getInstance() {
return getDateTimeInstance(SHORT, SHORT);
}
/**
* 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
* {@link java.text.spi.DateFormatProvider DateFormatProvider} implementations.
* It must contain at least a Locale instance equal to
* {@link java.util.Locale#US Locale.US}.
*
* @return An array of locales for which localized
* DateFormat instances are available.
*/
public static Locale[] getAvailableLocales()
{
LocaleServiceProviderPool pool =
LocaleServiceProviderPool.getPool(DateFormatProvider.class);
return pool.getAvailableLocales();
}
/**
* Set the calendar to be used by this date format. Initially, the default
* calendar for the specified or default locale is used.
*
*
Any {@link java.util.TimeZone TimeZone} and {@linkplain * #isLenient() leniency} values that have previously been set are * overwritten by {@code newCalendar}'s values. * * @param newCalendar the new {@code Calendar} to be used by the date format */ public void setCalendar(Calendar newCalendar) { this.calendar = newCalendar; } /** * Gets the calendar associated with this date/time formatter. * * @return the calendar associated with this date/time formatter. */ public Calendar getCalendar() { return calendar; } /** * Allows you to set the number formatter. * @param newNumberFormat the given new NumberFormat. */ public void setNumberFormat(NumberFormat newNumberFormat) { this.numberFormat = newNumberFormat; } /** * Gets the number formatter which this date/time formatter uses to * format and parse a time. * @return the number formatter which this date/time formatter uses. */ public NumberFormat getNumberFormat() { return numberFormat; } /** * Sets the time zone for the calendar of this {@code DateFormat} object. * This method is equivalent to the following call. *
* getCalendar().setTimeZone(zone)
* The {@code TimeZone} set by this method is overwritten by a * {@link #setCalendar(java.util.Calendar) setCalendar} call. * *
The {@code TimeZone} set by this method may be overwritten as * a result of a call to the parse method. * * @param zone the given new time zone. */ public void setTimeZone(TimeZone zone) { calendar.setTimeZone(zone); } /** * Gets the time zone. * This method is equivalent to the following call. *
* getCalendar().getTimeZone()
* This method is equivalent to the following call. *
* getCalendar().setLenient(lenient)
* This leniency value is overwritten by a call to {@link * #setCalendar(java.util.Calendar) setCalendar()}. * * @param lenient when {@code true}, parsing is lenient * @see java.util.Calendar#setLenient(boolean) */ public void setLenient(boolean lenient) { calendar.setLenient(lenient); } /** * Tell whether date/time parsing is to be lenient. * This method is equivalent to the following call. *
* getCalendar().isLenient()
* AttributedCharacterIterator returned
* from DateFormat.formatToCharacterIterator and as
* field identifiers in FieldPosition.
*
* The class also provides two methods to map
* between its constants and the corresponding Calendar constants.
*
* @since 1.4
* @see java.util.Calendar
*/
public static class Field extends Format.Field {
// Proclaim serial compatibility with 1.4 FCS
private static final long serialVersionUID = 7441350119349544720L;
// table of all instances in this class, used by readResolve
private static final Map instanceMap = new HashMap(18);
// Maps from Calendar constant (such as Calendar.ERA) to Field
// constant (such as Field.ERA).
private static final Field[] calendarToFieldMapping =
new Field[Calendar.FIELD_COUNT];
/** Calendar field. */
private int calendarField;
/**
* Returns the Field constant that corresponds to
* the Calendar constant calendarField.
* If there is no direct mapping between the Calendar
* constant and a Field, null is returned.
*
* @throws IllegalArgumentException if calendarField is
* not the value of a Calendar field constant.
* @param calendarField Calendar field constant
* @return Field instance representing calendarField.
* @see java.util.Calendar
*/
public static Field ofCalendarField(int calendarField) {
if (calendarField < 0 || calendarField >=
calendarToFieldMapping.length) {
throw new IllegalArgumentException("Unknown Calendar constant "
+ calendarField);
}
return calendarToFieldMapping[calendarField];
}
/**
* Creates a Field.
*
* @param name the name of the Field
* @param calendarField the Calendar constant this
* Field corresponds to; any value, even one
* outside the range of legal Calendar values may
* be used, but -1 should be used for values
* that don't correspond to legal Calendar values
*/
protected Field(String name, int calendarField) {
super(name);
this.calendarField = calendarField;
if (this.getClass() == DateFormat.Field.class) {
instanceMap.put(name, this);
if (calendarField >= 0) {
// assert(calendarField < Calendar.FIELD_COUNT);
calendarToFieldMapping[calendarField] = this;
}
}
}
/**
* Returns the Calendar field associated with this
* attribute. For example, if this represents the hours field of
* a Calendar, this would return
* Calendar.HOUR. If there is no corresponding
* Calendar constant, this will return -1.
*
* @return Calendar constant for this field
* @see java.util.Calendar
*/
public int getCalendarField() {
return calendarField;
}
/**
* Resolves instances being deserialized to the predefined constants.
*
* @throws InvalidObjectException if the constant could not be
* resolved.
* @return resolved DateFormat.Field constant
*/
protected Object readResolve() throws InvalidObjectException {
if (this.getClass() != DateFormat.Field.class) {
throw new InvalidObjectException("subclass didn't correctly implement readResolve");
}
Object instance = instanceMap.get(getName());
if (instance != null) {
return instance;
} else {
throw new InvalidObjectException("unknown attribute name");
}
}
//
// The constants
//
/**
* Constant identifying the era field.
*/
public final static Field ERA = new Field("era", Calendar.ERA);
/**
* Constant identifying the year field.
*/
public final static Field YEAR = new Field("year", Calendar.YEAR);
/**
* Constant identifying the month field.
*/
public final static Field MONTH = new Field("month", Calendar.MONTH);
/**
* Constant identifying the day of month field.
*/
public final static Field DAY_OF_MONTH = new
Field("day of month", Calendar.DAY_OF_MONTH);
/**
* Constant identifying the hour of day field, where the legal values
* are 1 to 24.
*/
public final static Field HOUR_OF_DAY1 = new Field("hour of day 1",-1);
/**
* Constant identifying the hour of day field, where the legal values
* are 0 to 23.
*/
public final static Field HOUR_OF_DAY0 = new
Field("hour of day", Calendar.HOUR_OF_DAY);
/**
* Constant identifying the minute field.
*/
public final static Field MINUTE =new Field("minute", Calendar.MINUTE);
/**
* Constant identifying the second field.
*/
public final static Field SECOND =new Field("second", Calendar.SECOND);
/**
* Constant identifying the millisecond field.
*/
public final static Field MILLISECOND = new
Field("millisecond", Calendar.MILLISECOND);
/**
* Constant identifying the day of week field.
*/
public final static Field DAY_OF_WEEK = new
Field("day of week", Calendar.DAY_OF_WEEK);
/**
* Constant identifying the day of year field.
*/
public final static Field DAY_OF_YEAR = new
Field("day of year", Calendar.DAY_OF_YEAR);
/**
* Constant identifying the day of week field.
*/
public final static Field DAY_OF_WEEK_IN_MONTH =
new Field("day of week in month",
Calendar.DAY_OF_WEEK_IN_MONTH);
/**
* Constant identifying the week of year field.
*/
public final static Field WEEK_OF_YEAR = new
Field("week of year", Calendar.WEEK_OF_YEAR);
/**
* Constant identifying the week of month field.
*/
public final static Field WEEK_OF_MONTH = new
Field("week of month", Calendar.WEEK_OF_MONTH);
/**
* Constant identifying the time of day indicator
* (e.g. "a.m." or "p.m.") field.
*/
public final static Field AM_PM = new
Field("am pm", Calendar.AM_PM);
/**
* Constant identifying the hour field, where the legal values are
* 1 to 12.
*/
public final static Field HOUR1 = new Field("hour 1", -1);
/**
* Constant identifying the hour field, where the legal values are
* 0 to 11.
*/
public final static Field HOUR0 = new
Field("hour", Calendar.HOUR);
/**
* Constant identifying the time zone field.
*/
public final static Field TIME_ZONE = new Field("time zone", -1);
}
/**
* Obtains a DateFormat instance from a DateFormatProvider
* implementation.
*/
private static class DateFormatGetter
implements LocaleServiceProviderPool.LocalizedObjectGetter