/*
 
* Copyright (c) 1996, 2013, Oracle and/or its affiliates. All rights reserved.
 
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 
*
 
* This code is free software; you can redistribute it and/or modify it
 
* under the terms of the GNU General Public License version 2 only, as
 
* published by the Free Software Foundation.
  
Oracle designates this
 
* particular file as subject to the "Classpath" exception as provided
 
* by Oracle in the LICENSE file that accompanied this code.
 
*
 
* This code is distributed in the hope that it will be useful, but WITHOUT
 
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 
* FITNESS FOR A PARTICULAR PURPOSE.
  
See the GNU General Public License
 
* version 2 for more details (a copy is included in the LICENSE file that
 
* accompanied this code).
 
*
 
* You should have received a copy of the GNU General Public License version
 
* 2 along with this work; if not, write to the Free Software Foundation,
 
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 
*
 
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 
* or visit www.oracle.com if you need additional information or have any
 
* questions.
 
*/

/*
 
* (C) Copyright Taligent, Inc. 1996 - All Rights Reserved
 
* (C) Copyright IBM Corp. 1996 - All Rights Reserved
 
*
 
*
   
The original version of this source code and documentation is copyrighted
 
* and owned by Taligent, Inc., a wholly-owned subsidiary of IBM. These
 
* materials are provided under terms of a License Agreement between Taligent
 
* and Sun. This technology is protected by multiple US and International
 
* patents. This notice and attribution to Taligent may not be removed.
 
*
   
Taligent is a registered trademark of Taligent, Inc.
 
*
 
*/


package java.text;

import java.io.InvalidObjectException;
import java.text.spi.DateFormatProvider;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;
import java.util.MissingResourceException;
import java.util.ResourceBundle;
import java.util.TimeZone;
import java.util.spi.LocaleServiceProvider;
import sun.util.locale.provider.LocaleProviderAdapter;
import sun.util.locale.provider.LocaleServiceProviderPool;

/**
 
* {@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 {@link SimpleDateFormat}, allows for
 
* formatting (i.e., date → text), parsing (text → date), and
 
* normalization.
  
The date is represented as a <code>Date</code> object or
 
* as the milliseconds since January 1, 1970, 00:00:00 GMT.
 
*
 
* <p>{@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 #LONG}, {@link #MEDIUM}, and {@link #SHORT}. More
 
* detail and examples of using these styles are provided in the method
 
* descriptions.
 
*
 
* <p>{@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.
 
*
 
* <p>To format a date for the current Locale, use one of the
 
* static factory methods:
 
* <blockquote>
 
* <pre>{@code
 
* myString = DateFormat.getDateInstance().format(myDate);
 
* }</pre>
 
* </blockquote>
 
* <p>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.
 
* <blockquote>
 
* <pre>{@code
 
* DateFormat df = DateFormat.getDateInstance();
 
* for (int i = 0; i < myDate.length; ++i) {
 
*
     
output.println(df.format(myDate[i]) + "; ");
 
* }
 
* }</pre>
 
* </blockquote>
 
* <p>To format a date for a different Locale, specify it in the
 
* call to {@link #getDateInstance(int, Locale) getDateInstance()}.
 
* <blockquote>
 
* <pre>{@code
 
* DateFormat df = DateFormat.getDateInstance(DateFormat.LONG, Locale.FRANCE);
 
* }</pre>
 
* </blockquote>
 
* <p>You can use a DateFormat to parse also.
 
* <blockquote>
 
* <pre>{@code
 
* myDate = df.parse(myString);
 
* }</pre>
 
* </blockquote>
 
* <p>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
 
to {@link #MEDIUM} to {@link #LONG} to {@link #FULL}. The exact result depends
 
* on the locale, but generally:
 
* <ul><li>
 
is completely numeric, such as {@code 12.13.52} or {@code 3:30pm}
 
* <li>
 
is longer, such as {@code Jan 12, 1952}
 
* <li>
 
is longer, such as {@code January 12, 1952} or {@code 3:30:32pm}
 
* <li>
 
is pretty completely specified, such as
 
* {@code Tuesday, April 12, 1952 AD or 3:30:42pm PST}.
 
* </ul>
 
*
 
* <p>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.
 
*
 
* <p>You can also use forms of the parse and format methods with
 
* {@link ParsePosition} and {@link FieldPosition} to
 
* allow you to
 
* <ul><li>progressively parse through pieces of a string.
 
* <li>align any particular field, or find out where it is for selection
 
* on the screen.
 
* </ul>
 
*
 
* <h3><a name="synchronization">Synchronization</a></h3>
 
*
 
* <p>
 
* 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.
     
*
     
* <p>Subclasses should initialize this field to a {@link Calendar}
     
* appropriate for the {@link Locale} associated with this
     
* <code>DateFormat</code>.
     
* @serial
     
*/

    
protected Calendar calendar;

    
/**
     
* The number formatter that <code>DateFormat</code> uses to format numbers
     
* in dates and times.
  
Subclasses should initialize this to a number format
     
* appropriate for the locale associated with this <code>DateFormat</code>.
     
* @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'.
     
*
 

     
*/

    
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.
     
* <p>
     
* See the {@link #parse(String, ParsePosition)} method for more information
     
* on date parsing.
     
*
     
* @param source A <code>String</code> whose beginning should be parsed.
     
* @return A <code>Date</code> 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)}.
     
*
     
* <p> 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)}.
     
*
     
* <p>This parsing operation uses the
 
 
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 <code>Date</code>.
     
* <p>
     
* The method attempts to parse text starting at the index given by
     
* <code>pos</code>.
     
* If parsing succeeds, then the index of <code>pos</code> 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 <code>pos</code> can be used to
     
* indicate the starting point for the next call to this method.
     
* If an error occurs, then the index of <code>pos</code> is not
     
* changed, the error index of <code>pos</code> is set to the index of
     
* the character where the error occurred, and null is returned.
     
* <p>
     
* See the {@link #parse(String, ParsePosition)} method for more information
     
* on date parsing.
     
*
     
* @param source A <code>String</code>, part of which should be parsed.
     
* @param pos A <code>ParsePosition</code> object with index and error
     
*
            
index information as described above.
     
* @return A <code>Date</code> parsed from the string. In case of
     
*
         
error, returns null.
     
* @exception NullPointerException if <code>pos</code> 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 {@link java.util.Locale.Category#FORMAT FORMAT} locale.
     
* <p>This is equivalent to calling
     
* {@link #getTimeInstance(int, Locale) getTimeInstance(DEFAULT,
     
*Locale.getDefault(Locale.Category.FORMAT))}.
     
* @see java.util.Locale#getDefault(java.util.Locale.Category)
     
*
 

     
* @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 {@link java.util.Locale.Category#FORMAT FORMAT} locale.
     
* <p>This is equivalent to calling
     
* {@link #getTimeInstance(int, Locale) getTimeInstance(style,
     
*Locale.getDefault(Locale.Category.FORMAT))}.
     
* @see java.util.Locale#getDefault(java.util.Locale.Category)
     
*
 

     
* @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 {@link java.util.Locale.Category#FORMAT FORMAT} locale.
     
* <p>This is equivalent to calling
     
* {@link #getDateInstance(int, Locale) getDateInstance(DEFAULT,
     
*Locale.getDefault(Locale.Category.FORMAT))}.
     
* @see java.util.Locale#getDefault(java.util.Locale.Category)
     
*
 

     
* @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 {@link java.util.Locale.Category#FORMAT FORMAT} locale.
     
* <p>This is equivalent to calling
     
* {@link #getDateInstance(int, Locale) getDateInstance(style,
     
*Locale.getDefault(Locale.Category.FORMAT))}.
     
* @see java.util.Locale#getDefault(java.util.Locale.Category)
     
*
 

     
* @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 {@link java.util.Locale.Category#FORMAT FORMAT} locale.
     
* <p>This is equivalent to calling
     
* {@link #getDateTimeInstance(int, int, Locale) getDateTimeInstance(DEFAULT,
     
*DEFAULT, Locale.getDefault(Locale.Category.FORMAT))}.
     
* @see java.util.Locale#getDefault(java.util.Locale.Category)
     
*
 

     
* @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 {@link java.util.Locale.Category#FORMAT FORMAT} locale.
     
* <p>This is equivalent to calling
     
* {@link #getDateTimeInstance(int, int, Locale) getDateTimeInstance(dateStyle,
     
*timeStyle, Locale.getDefault(Locale.Category.FORMAT))}.
     
* @see java.util.Locale#getDefault(java.util.Locale.Category)
     
*
 

     
* @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.
     
*
     
* @return a date/time formatter
     
*/

    
public final static DateFormat getInstance() {
        
return getDateTimeInstance(SHORT, SHORT);
    
}

    
/**
     
* Returns an array of all locales for which the
     
* <code>get*Instance</code> 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 <code>Locale</code> instance equal to
     
* {@link java.util.Locale#US Locale.US}.
     
*
     
* @return An array of locales for which localized
     
*
         
<code>DateFormat</code> 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.
     
*
     
* <p>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.
     
* <blockquote><pre>{@code
     
* getCalendar().setTimeZone(zone)
     
* }</pre></blockquote>
     
*
     
* <p>The {@code TimeZone} set by this method is overwritten by a
     
* {@link #setCalendar(java.util.Calendar) setCalendar} call.
     
*
     
* <p>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.
     
* <blockquote><pre>{@code
     
* getCalendar().getTimeZone()
     
* }</pre></blockquote>
     
*
     
* @return the time zone associated with the calendar of DateFormat.
     
*/

    
public TimeZone getTimeZone()
    
{
        
return calendar.getTimeZone();
    
}

    
/**
     
* 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.
     
*
     
* <p>This method is equivalent to the following call.
     
* <blockquote><pre>{@code
     
* getCalendar().setLenient(lenient)
     
* }</pre></blockquote>
     
*
     
* <p>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.
     
* <blockquote><pre>{@code
     
* getCalendar().isLenient()
     
* }</pre></blockquote>
     
*
     
* @return {@code true} if the
 
 
is lenient;
     
*
         
{@code false} otherwise.
     
* @see java.util.Calendar#isLenient()
     
*/

    
public boolean isLenient()
    
{
        
return calendar.isLenient();
    
}

    
/**
     
* Overrides hashCode
     
*/
    
public int hashCode() {
        
return numberFormat.hashCode();
        
// just enough fields for a reasonable distribution
    
}

    
/**
     
* Overrides equals
     
*/
    
public boolean equals(Object obj) {
        
if (this == obj) return true;
        
if (obj == null || getClass() != obj.getClass()) return false;
        
DateFormat other = (DateFormat) obj;
        
return (// calendar.equivalentTo(other.calendar) // THIS API DOESN'T EXIST YET!
                
calendar.getFirstDayOfWeek() == other.calendar.getFirstDayOfWeek() &&
                
calendar.getMinimalDaysInFirstWeek() == other.calendar.getMinimalDaysInFirstWeek() &&
                
calendar.isLenient() == other.calendar.isLenient() &&
                
calendar.getTimeZone().equals(other.calendar.getTimeZone()) &&
                
numberFormat.equals(other.numberFormat));
    
}

    
/**
     
* Overrides Cloneable
     
*/
    
public Object clone()
    
{
        
DateFormat other = (DateFormat) super.clone();
        
other.calendar = (Calendar) calendar.clone();
        
other.numberFormat = (NumberFormat) numberFormat.clone();
        
return other;
    
}

    
/**
     
* Creates a DateFormat with the given time and/or date style in the given
     
* locale.
     
* @param timeStyle a value from 0 to 3 indicating the time format,
     
* ignored if flags is 2
     
* @param dateStyle a value from 0 to 3 indicating the time format,
     
* ignored if flags is 1
     
* @param flags either 1 for a time format, 2 for a date format,
     
* or 3 for a date/time format
     
* @param loc the locale for the format
     
*/

    
private static DateFormat get(int timeStyle, int dateStyle,
                                  
int flags, Locale loc) {
        
if ((flags & 1) != 0) {
            
if (timeStyle < 0 || timeStyle > 3) {
                
throw new IllegalArgumentException("Illegal time style " + timeStyle);
            
}
        
} else {
            
timeStyle = -1;
        
}
        
if ((flags & 2) != 0) {
            
if (dateStyle < 0 || dateStyle > 3) {
                
throw new IllegalArgumentException("Illegal date style " + dateStyle);
            
}
        
} else {
            
dateStyle = -1;
        
}

        
LocaleProviderAdapter adapter = LocaleProviderAdapter.getAdapter(DateFormatProvider.class, loc);
        
DateFormat dateFormat = get(adapter, timeStyle, dateStyle, loc);
        
if (dateFormat == null) {
            
dateFormat = get(LocaleProviderAdapter.forJRE(), timeStyle, dateStyle, loc);
        
}
        
return dateFormat;
    
}

    
private static DateFormat get(LocaleProviderAdapter adapter, int timeStyle, int dateStyle, Locale loc) {
        
DateFormatProvider provider = adapter.getDateFormatProvider();
        
DateFormat dateFormat;
        
if (timeStyle == -1) {
            
dateFormat = provider.getDateInstance(dateStyle, loc);
        
} else {
            
if (dateStyle == -1) {
                
dateFormat = provider.getTimeInstance(timeStyle, loc);
            
} else {
                
dateFormat = provider.getDateTimeInstance(dateStyle, timeStyle, loc);
            
}
        
}
        
return dateFormat;
    
}

    
/**
     
* Create a new date format.
     
*/
    
protected DateFormat() {}

    
/**
     
* Defines constants that are used as attribute keys in the
     
* <code>AttributedCharacterIterator</code> returned
     
* from <code>DateFormat.formatToCharacterIterator</code> and as
     
* field identifiers in <code>FieldPosition</code>.
     
* <p>
     
* The class also provides two methods to map
     
* between its constants and the corresponding Calendar constants.
     
*
     
* @since 1.4
     
*
 

     
*/

    
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<String, Field> 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 <code>Field</code> constant that corresponds to
         
* the <code>Calendar</code> constant <code>calendarField</code>.
         
* If there is no direct mapping between the <code>Calendar</code>
         
* constant and a <code>Field</code>, null is returned.
         
*
         
* @throws IllegalArgumentException if <code>calendarField</code> is
         
*not the value of a <code>Calendar</code> field constant.
         
* @param calendarField Calendar field constant
         
* @return Field instance representing calendarField.
         
*
 

         
*/

        
public static Field ofCalendarField(int calendarField) {
            
if (calendarField < 0 || calendarField >=
                        
calendarToFieldMapping.length) {
                
throw new IllegalArgumentException("Unknown Calendar constant "
                                                   
+ calendarField);
            
}
            
return calendarToFieldMapping[calendarField];
        
}

        
/**
         
* Creates a <code>Field</code>.
         
*
         
* @param name the name of the <code>Field</code>
         
* @param calendarField the <code>Calendar</code> constant this
         
*
        
<code>Field</code> corresponds to; any value, even one
         
*
        
outside the range of legal <code>Calendar</code> values may
         
*
        
be used, but <code>-1</code> should be used for values
         
*
        
that don't correspond to legal <code>Calendar</code> 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 <code>Calendar</code> field associated with this
         
* attribute. For example, if this represents the hours field of
         
* a <code>Calendar</code>, this would return
         
* <code>Calendar.HOUR</code>. If there is no corresponding
         
* <code>Calendar</code> constant, this will return -1.
         
*
         
* @return Calendar constant for this field
         
*
 

         
*/

        
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
         
*/

        
@Override
        
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);
    
}
}