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java.text
abstract public class: DateFormat [javadoc | source]
java.lang.Object
   java.text.Format
      java.text.DateFormat

All Implemented Interfaces:
    Cloneable, Serializable

Direct Known Subclasses:
    SimpleDateFormat

{@code 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.

{@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 #FULL , #LONG , #MEDIUM , and #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 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 #SHORT to #MEDIUM to #LONG to #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 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 ParsePosition and FieldPosition to allow you to

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:
public static class  DateFormat.Field  Defines constants that are used as attribute keys in the 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. 

Field Summary
protected  Calendar 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.

    serial:
 
protected  NumberFormat 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.
    serial:
 
public static final  int ERA_FIELD    Useful constant for ERA field alignment. Used in FieldPosition of date/time formatting. 
public static final  int YEAR_FIELD    Useful constant for YEAR field alignment. Used in FieldPosition of date/time formatting. 
public static final  int MONTH_FIELD    Useful constant for MONTH field alignment. Used in FieldPosition of date/time formatting. 
public static final  int DATE_FIELD    Useful constant for DATE field alignment. Used in FieldPosition of date/time formatting. 
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. 
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. 
public static final  int MINUTE_FIELD    Useful constant for MINUTE field alignment. Used in FieldPosition of date/time formatting. 
public static final  int SECOND_FIELD    Useful constant for SECOND field alignment. Used in FieldPosition of date/time formatting. 
public static final  int MILLISECOND_FIELD    Useful constant for MILLISECOND field alignment. Used in FieldPosition of date/time formatting. 
public static final  int DAY_OF_WEEK_FIELD    Useful constant for DAY_OF_WEEK field alignment. Used in FieldPosition of date/time formatting. 
public static final  int DAY_OF_YEAR_FIELD    Useful constant for DAY_OF_YEAR field alignment. Used in FieldPosition of date/time formatting. 
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. 
public static final  int WEEK_OF_YEAR_FIELD    Useful constant for WEEK_OF_YEAR field alignment. Used in FieldPosition of date/time formatting. 
public static final  int WEEK_OF_MONTH_FIELD    Useful constant for WEEK_OF_MONTH field alignment. Used in FieldPosition of date/time formatting. 
public static final  int AM_PM_FIELD    Useful constant for AM_PM field alignment. Used in FieldPosition of date/time formatting. 
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. 
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. 
public static final  int TIMEZONE_FIELD    Useful constant for TIMEZONE field alignment. Used in FieldPosition of date/time formatting. 
public static final  int FULL    Constant for full style pattern. 
public static final  int LONG    Constant for long style pattern. 
public static final  int MEDIUM    Constant for medium style pattern. 
public static final  int SHORT    Constant for short style pattern. 
public static final  int DEFAULT    Constant for default style pattern. Its value is MEDIUM. 
Constructor:
 protected DateFormat() 
Method from java.text.DateFormat Summary:
clone,   equals,   format,   format,   format,   getAvailableLocales,   getCalendar,   getDateInstance,   getDateInstance,   getDateInstance,   getDateTimeInstance,   getDateTimeInstance,   getDateTimeInstance,   getInstance,   getNumberFormat,   getTimeInstance,   getTimeInstance,   getTimeInstance,   getTimeZone,   hashCode,   isLenient,   parse,   parse,   parseObject,   setCalendar,   setLenient,   setNumberFormat,   setTimeZone
Methods from java.text.Format:
clone,   createAttributedCharacterIterator,   createAttributedCharacterIterator,   createAttributedCharacterIterator,   createAttributedCharacterIterator,   format,   format,   formatToCharacterIterator,   parseObject,   parseObject
Methods from java.lang.Object:
clone,   equals,   finalize,   getClass,   hashCode,   notify,   notifyAll,   toString,   wait,   wait,   wait
Method from java.text.DateFormat Detail:
 public Object clone() 
    Overrides Cloneable
 public boolean equals(Object obj) 
    Overrides equals
 public final String format(Date date) 
    Formats a Date into a date/time string.
 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.
 abstract public StringBuffer format(Date date,
    StringBuffer toAppendTo,
    FieldPosition fieldPosition)
    Formats a Date into a date/time string.
 public static Locale[] 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 .
 public Calendar getCalendar() 
    Gets the calendar associated with this date/time formatter.
 public static final DateFormat getDateInstance() 
    Gets the date formatter with the default formatting style for the default locale.
 public static final DateFormat getDateInstance(int style) 
    Gets the date formatter with the given formatting style for the default locale.
 public static final DateFormat getDateInstance(int style,
    Locale aLocale) 
    Gets the date formatter with the given formatting style for the given locale.
 public static final DateFormat getDateTimeInstance() 
    Gets the date/time formatter with the default formatting style for the default locale.
 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 locale.
 public static final DateFormat getDateTimeInstance(int dateStyle,
    int timeStyle,
    Locale aLocale) 
    Gets the date/time formatter with the given formatting styles for the given locale.
 public static final DateFormat getInstance() 
    Get a default date/time formatter that uses the SHORT style for both the date and the time.
 public NumberFormat getNumberFormat() 
    Gets the number formatter which this date/time formatter uses to format and parse a time.
 public static final DateFormat getTimeInstance() 
    Gets the time formatter with the default formatting style for the default locale.
 public static final DateFormat getTimeInstance(int style) 
    Gets the time formatter with the given formatting style for the default locale.
 public static final DateFormat getTimeInstance(int style,
    Locale aLocale) 
    Gets the time formatter with the given formatting style for the given locale.
 public TimeZone getTimeZone() 
    Gets the time zone. This method is equivalent to the following call.
     getCalendar().getTimeZone()
    
 public int hashCode() 
    Overrides hashCode
 public boolean isLenient() 
    Tell whether date/time parsing is to be lenient. This method is equivalent to the following call.
     getCalendar().isLenient()
    
 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.

 abstract public Date parse(String source,
    ParsePosition pos)
    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 setLenient(false) .

    This parsing operation uses the #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 setTimeZone may need to be restored for further operations.

 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.

 public  void setCalendar(Calendar newCalendar) 
    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 {@linkplain #isLenient() leniency} values that have previously been set are overwritten by {@code newCalendar}'s values.

 public  void setLenient(boolean lenient) 
    Specify whether or not date/time parsing is to be lenient. With lenient parsing, the parser may use heuristics to interpret inputs that do not precisely match this object's format. With strict parsing, inputs must match this object's format.

    This method is equivalent to the following call.

     getCalendar().setLenient(lenient)
    

    This leniency value is overwritten by a call to setCalendar() .

 public  void setNumberFormat(NumberFormat newNumberFormat) 
    Allows you to set the number formatter.
 public  void setTimeZone(TimeZone zone) 
    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 setCalendar call.

    The {@code TimeZone} set by this method may be overwritten as a result of a call to the parse method.