[Chapter 29] 29.7 java.text.DateFormat (JDK 1.1)

#

| Chapter 29 The java.text Package |

## 29.7 java.text.DateFormat (JDK 1.1)

###

This class formats and parses dates and times in a locale-specific way. As an abstract class, it cannot be instantiated directly, but it provides a number of static methods that return instances of a concrete subclass which you can use to format dates in a variety of ways. The `getDateInstance()` methods return a `DateFormat` object suitable for formatting dates in either the default locale or a specified locale. A formatting style may also optionally be specified--the constants `FULL`, `LONG`, `MEDIUM`, `SHORT`, and `DEFAULT` specify this style. Similarly, the `getTimeInstance()` methods return a `DateFormat` object that formats and parses times, and the `getDateTimeInstance()` methods return a `DateFormat` object that formats both dates and times. These methods also optionally take a format style constant and a `Locale`. Finally, `getInstance()` returns a default `DateFormat` object that formats both dates and times in the `SHORT` format.

Once you have created a `DateFormat` object, you can use the `setCalendar()` and `setTimeZone()` methods if you want to format the date using a calendar or time zone other than the default.

The various `format()` methods convert `java.util.Date` objects to strings, using whatever format is encapsulated in the `DateFormat` object. The `parse()` and `parseObject()` methods perform the reverse operation--they parse a string formatted according to the rules of the `DateFormat` object and convert it into a `Date` object.

The `DEFAULT`, `FULL`, `MEDIUM`, `LONG`, and `SHORT` constants are used to specify how verbose or compact the formatted date or time should be. The remaining constants, which all end with `_FIELD`, specify various fields of formatted dates and times and are used with the `FieldPosition` object that is optionally passed to `format()`.

    public abstract class DateFormat extends Format implements Cloneable {
        // Protected Constructor
                protected DateFormat();
        // Format Style Constants
                public static final int DEFAULT;
                public static final int FULL;
                public static final int LONG;
                public static final int MEDIUM;
                public static final int SHORT;
        // Date and Time Field Constants
                public static final int ERA_FIELD;
                public static final int YEAR_FIELD;
                public static final int MONTH_FIELD;
                public static final int WEEK_OF_MONTH_FIELD, WEEK_OF_YEAR_FIELD;
                public static final int DATE_FIELD, DAY_OF_YEAR_FIELD;
                public static final int DAY_OF_WEEK_FIELD, DAY_OF_WEEK_IN_MONTH_FIELD;
                public static final int TIMEZONE_FIELD;
                public static final int AM_PM_FIELD;
                public static final int HOUR0_FIELD, HOUR1_FIELD;
                public static final int HOUR_OF_DAY0_FIELD, HOUR_OF_DAY1_FIELD;
                public static final int MINUTE_FIELD;
                public static final int SECOND_FIELD;
                public static final int MILLISECOND_FIELD;
        // Protected Instance Variables
                protected Calendar calendar;
                protected NumberFormat numberFormat;
        // Class Methods
                public static Locale[] getAvailableLocales();
                public static final DateFormat getDateInstance();
                public static final DateFormat getDateInstance(int style);
                public static final DateFormat getDateInstance(int style, Locale aLocale);
                public static final DateFormat getDateTimeInstance();
                public static final DateFormat getDateTimeInstance(int dateStyle, int timeStyle);
                public static final DateFormat getDateTimeInstance(int dateStyle, int timeStyle, Locale aLocale);
                public static final DateFormat getInstance();
                public static final DateFormat getTimeInstance();
                public static final DateFormat getTimeInstance(int style);
                public static final DateFormat getTimeInstance(int style, Locale aLocale);
        // Public Instance Methods
                public Object clone();  // Overrides Format
                public boolean equals(Object obj);  // Overrides Object
                public final StringBuffer format(Object obj, StringBuffer toAppendTo, FieldPosition fieldPosition);  // Defines Format
                public abstract StringBuffer format(Date date, StringBuffer toAppendTo, FieldPosition fieldPosition);
                public final String format(Date date);
                public Calendar getCalendar();
                public NumberFormat getNumberFormat();
                public TimeZone getTimeZone();
                public int hashCode();  // Overrides Object
                public boolean isLenient();
                public Date parse(String text) throws ParseException;
                public abstract Date parse(String text, ParsePosition pos);
                public Object parseObject(String source, ParsePosition pos);  // Defines Format
                public void setCalendar(Calendar newCalendar);
                public void setLenient(boolean lenient);
                public void setNumberFormat(NumberFormat newNumberFormat);
                public void setTimeZone(TimeZone zone);
    }

### Hierarchy:

Object->Format(Serializable, Cloneable)->DateFormat(Cloneable)

### Extended By:

SimpleDateFormat

### Returned By:

DateFormat.getDateInstance(), DateFormat.getDateTimeInstance(), DateFormat.getInstance(), DateFormat.getTimeInstance()

java.text.Collator (JDK 1.1) |  | java.text.DateFormatSymbols (JDK 1.1)