org.apache.velocity.tools.generic
Class DateTool

java.lang.Object
  extended by org.apache.velocity.tools.generic.SafeConfig
      extended by org.apache.velocity.tools.generic.LocaleConfig
          extended by org.apache.velocity.tools.generic.FormatConfig
              extended by org.apache.velocity.tools.generic.DateTool
Direct Known Subclasses:
ComparisonDateTool

@DefaultKey(value="date")
public class DateTool
extends FormatConfig

Tool for working with Date and Calendar in Velocity templates. It is useful for accessing and formatting the "current" date as well as for formatting arbitrary Date and Calendar objects. Also the tool can be used to retrieve DateFormat instances or make conversions to and from various date types.

 Example of formatting the "current" date:
  $date                         -> Oct 19, 2003 9:54:50 PM
  $date.long                    -> October 19, 2003 9:54:50 PM PDT
  $date.medium_time             -> 9:54:50 PM
  $date.full_date               -> Sunday, October 19, 2003
  $date.get('default','short')  -> Oct 19, 2003 9:54 PM
  $date.get('yyyy-M-d H:m:s')   -> 2003-10-19 21:54:50

 Example of formatting an arbitrary date:
  $myDate                        -> Tue Oct 07 03:14:50 PDT 2003
  $date.format('medium',$myDate) -> Oct 7, 2003 3:14:50 AM

 Example tools.xml config (if you want to use this with VelocityView):
 <tools>
   <toolbox scope="application">
     <tool class="org.apache.velocity.tools.generic.DateTool"
              format="yyyy-MM-dd"/>
   </toolbox>
 </tools>
 

The methods of this tool are highly interconnected, and overriding key methods provides an easy way to create subclasses that use a non-default format, calendar, locale, or timezone.

Since:
VelocityTools 1.0
Version:
$Revision: 719489 $ $Date: 2008-11-21 07:05:11 +0100 (ven., 21 nov. 2008) $
Author:
Nathan Bubna

Field Summary
static String DEFAULT_FORMAT_KEY
          Deprecated. 
static String DEFAULT_LOCALE_KEY
          Deprecated. 
static String TIMEZONE_KEY
          The key used for specifying a default timezone via tool configuration.
 
Fields inherited from class org.apache.velocity.tools.generic.FormatConfig
DEFAULT_FORMAT, FORMAT_KEY
 
Fields inherited from class org.apache.velocity.tools.generic.LocaleConfig
DEFAULT_LOCALE
 
Fields inherited from class org.apache.velocity.tools.generic.SafeConfig
LOCK_CONFIG_KEY, OLD_LOCK_CONFIG_KEY, SAFE_MODE_KEY
 
Constructor Summary
DateTool()
           
 
Method Summary
protected  void configure(ValueParser values)
          Does the actual configuration.
 String format(Object obj)
          Converts the specified object to a date and formats it according to the pattern or style returned by FormatConfig.getFormat().
 String format(String format, Object obj)
          Converts the specified object to a date and returns a formatted string representing that date in the locale returned by LocaleConfig.getLocale().
 String format(String format, Object obj, Locale locale)
          Converts the specified object to a date and returns a formatted string representing that date in the specified Locale.
 String format(String format, Object obj, Locale locale, TimeZone timezone)
          Returns a formatted string representing the specified date, Locale, and TimeZone.
 String format(String dateStyle, String timeStyle, Object obj)
          Returns the specified date as a string formatted according to the specified date and/or time styles.
 String format(String dateStyle, String timeStyle, Object obj, Locale locale)
          Returns the specified date as a string formatted according to the specified Locale and date and/or time styles.
 String format(String dateStyle, String timeStyle, Object obj, Locale locale, TimeZone timezone)
          Returns the specified date as a string formatted according to the specified Locale and date and/or time styles.
 String get(String format)
          Returns a formatted string representing the date returned by getDate().
 String get(String dateStyle, String timeStyle)
          Returns a formatted string representing the date and/or time given by getDate() in standard, localized patterns.
 Calendar getCalendar()
          Returns a Calendar instance created using the timezone and locale returned by getTimeZone() and getLocale().
 Date getDate()
          Returns a Date derived from the result of getCalendar()
protected  DateFormat getDateFormat(int dateStyle, int timeStyle, Locale locale, TimeZone timezone)
          Deprecated. 
 DateFormat getDateFormat(String format, Locale locale, TimeZone timezone)
          Returns a DateFormat instance for the specified format, Locale, and TimeZone.
 DateFormat getDateFormat(String dateStyle, String timeStyle, Locale locale, TimeZone timezone)
          Returns a DateFormat instance for the specified date style, time style, Locale, and TimeZone.
 Integer getDay()
          Returns the day (of the month) value of the date returned by getCalendar().
 Integer getDay(Object date)
          Returns the day (of the month) value for the specified date.
 Integer getMonth()
          Returns the month value of the date returned by getCalendar().
 Integer getMonth(Object date)
          Returns the month value of the specified date.
protected  int getStyleAsInt(String style)
          Deprecated. 
static Calendar getSystemCalendar()
           
static Date getSystemDate()
           
static long getSystemTime()
           
 TimeZone getTimeZone()
          Returns the configured TimeZone.
 Integer getValue(int field, Object date)
          Returns the specified value of the specified date, or null if the field or date is invalid.
 Integer getValue(Object field)
          Return the specified value of the date returned by getCalendar() or null if the field is invalid.
 Integer getValue(Object field, Object date)
          Returns the specified value of the specified date, or null if the field or date is invalid.
 Integer getYear()
          Returns the year value of the date returned by getCalendar().
 Integer getYear(Object date)
          Returns the year value of the specified date.
protected  void setTimeZone(TimeZone timezone)
           
 Calendar toCalendar(Object obj)
          Converts an object to an instance of Calendar using the locale returned by LocaleConfig.getLocale() if necessary.
 Calendar toCalendar(Object obj, Locale locale)
          Converts an object to an instance of Calendar using the locale returned by LocaleConfig.getLocale() if necessary.
 Date toDate(Object obj)
          Converts an object to an instance of Date using the format returned by FormatConfig.getFormat(),the Locale returned by LocaleConfig.getLocale(), and the TimeZone returned by getTimeZone() if the object is not already an instance of Date, Calendar, or Long.
 Date toDate(String format, Object obj)
          Converts an object to an instance of Date using the specified format,the Locale returned by LocaleConfig.getLocale(), and the TimeZone returned by getTimeZone() if the object is not already an instance of Date, Calendar, or Long.
 Date toDate(String format, Object obj, Locale locale)
          Converts an object to an instance of Date using the specified format and Locale if the object is not already an instance of Date, Calendar, or Long.
 Date toDate(String format, Object obj, Locale locale, TimeZone timezone)
          Converts an object to an instance of Date using the specified format, Locale, and TimeZone if the object is not already an instance of Date, Calendar, or Long.
 String toString()
           
 
Methods inherited from class org.apache.velocity.tools.generic.FormatConfig
getFormat, setFormat
 
Methods inherited from class org.apache.velocity.tools.generic.LocaleConfig
getLocale, setLocale
 
Methods inherited from class org.apache.velocity.tools.generic.SafeConfig
configure, isConfigLocked, isSafeMode, setLockConfig, setSafeMode
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

DEFAULT_FORMAT_KEY

@Deprecated
public static final String DEFAULT_FORMAT_KEY
Deprecated. 
See Also:
Constant Field Values

DEFAULT_LOCALE_KEY

@Deprecated
public static final String DEFAULT_LOCALE_KEY
Deprecated. 
See Also:
Constant Field Values

TIMEZONE_KEY

public static final String TIMEZONE_KEY
The key used for specifying a default timezone via tool configuration.

See Also:
Constant Field Values
Constructor Detail

DateTool

public DateTool()
Method Detail

configure

protected void configure(ValueParser values)
Does the actual configuration. This is protected, so subclasses may share the same ValueParser and call configure at any time, while preventing templates from doing so when configure(Map) is locked.

Overrides:
configure in class FormatConfig

setTimeZone

protected void setTimeZone(TimeZone timezone)

getSystemTime

public static final long getSystemTime()
Returns:
the system's current time as the number of milliseconds elapsed since January 1, 1970, 00:00:00 GMT.

getSystemDate

public static final Date getSystemDate()
Returns:
the system's current time as a Date

getSystemCalendar

public static final Calendar getSystemCalendar()
Returns:
the system's current time as a Calendar

getTimeZone

public TimeZone getTimeZone()
Returns the configured TimeZone. Default value is from TimeZone.getDefault().

Returns:
the configured TimeZone

getDate

public Date getDate()
Returns a Date derived from the result of getCalendar()

Returns:
a Date derived from the result of getCalendar()

getCalendar

public Calendar getCalendar()
Returns a Calendar instance created using the timezone and locale returned by getTimeZone() and getLocale(). This allows subclasses to easily override the default locale and timezone used by this tool.

Sub-classes may override this method to return a Calendar instance not based on the system date. Doing so will also cause the getDate(), get(String), get(String,String), and toString() methods to return dates equivalent to the Calendar returned by this method, because those methods return values derived from the result of this method.

Returns:
a Calendar instance created using the results of getTimeZone() and LocaleConfig.getLocale().
See Also:
Calendar.getInstance(TimeZone zone, Locale aLocale)

getYear

public Integer getYear()
Returns the year value of the date returned by getCalendar().

Since:
VelocityTools 1.2

getYear

public Integer getYear(Object date)
Returns the year value of the specified date.

Since:
VelocityTools 1.2

getMonth

public Integer getMonth()
Returns the month value of the date returned by getCalendar().

Since:
VelocityTools 1.2

getMonth

public Integer getMonth(Object date)
Returns the month value of the specified date.

Since:
VelocityTools 1.2

getDay

public Integer getDay()
Returns the day (of the month) value of the date returned by getCalendar().

NOTE: Unlike java.util.Date, this returns the day of the month. It is equivalent to Date.getDate() and Calendar.get(Calendar.DAY_OF_MONTH). We could not call this method getDate() because that already exists in this class with a different function.

Since:
VelocityTools 1.2

getDay

public Integer getDay(Object date)
Returns the day (of the month) value for the specified date.

NOTE: Unlike java.util.Date, this returns the day of the month. It is equivalent to Date.getDate() and Calendar.get(Calendar.DAY_OF_MONTH). We could not call this method getDate() because that already exists in this class with a different function.

Since:
VelocityTools 1.2

getValue

public Integer getValue(Object field)
Return the specified value of the date returned by getCalendar() or null if the field is invalid.

Since:
VelocityTools 1.2

getValue

public Integer getValue(Object field,
                        Object date)
Returns the specified value of the specified date, or null if the field or date is invalid. The field may be an Integer or it may be the name of the field as a String.

Parameters:
field - the corresponding Integer value or String name of the desired value
date - the date/calendar from which the field value will be taken
Since:
VelocityTools 1.2

getValue

public Integer getValue(int field,
                        Object date)
Returns the specified value of the specified date, or null if the field or date is invalid.

Parameters:
field - the int for the desired field (e.g. Calendar.MONTH)
date - the date/calendar from which the field value will be taken
Since:
VelocityTools 1.2

get

public String get(String format)
Returns a formatted string representing the date returned by getDate(). In its default implementation, this method allows you to retrieve the current date in standard formats by simply doing things like $date.medium or $date.full. If you want only the date or time portion you can specify that along with the standard formats. (e.g. $date.medium_date or $date.short_time) More complex or custom formats can be retrieved by using the full method syntax. (e.g. $date.get('E, MMMM d'))

Parameters:
format - the formatting instructions
Returns:
a formatted representation of the date returned by getDate()
Since:
VelocityTools 1.1
See Also:
format(String format, Object obj, Locale locale, TimeZone timezone)

get

public String get(String dateStyle,
                  String timeStyle)
Returns a formatted string representing the date and/or time given by getDate() in standard, localized patterns.

Parameters:
dateStyle - the style pattern for the date
timeStyle - the style pattern for the time
Returns:
a formatted representation of the date returned by getDate()
Since:
VelocityTools 1.1
See Also:
DateFormat, format(String dateStyle, String timeStyle, Object obj, Locale locale, TimeZone timezone)

format

public String format(Object obj)
Converts the specified object to a date and formats it according to the pattern or style returned by FormatConfig.getFormat().

Parameters:
obj - the date object to be formatted
Returns:
the specified date formatted as a string
Since:
VelocityTools 1.1
See Also:
format(String format, Object obj, Locale locale, TimeZone timezone)

format

public String format(String format,
                     Object obj)
Converts the specified object to a date and returns a formatted string representing that date in the locale returned by LocaleConfig.getLocale().

Parameters:
format - the formatting instructions
obj - the date object to be formatted
Returns:
a formatted string for this locale representing the specified date or null if the parameters are invalid
See Also:
format(String format, Object obj, Locale locale, TimeZone timezone)

format

public String format(String format,
                     Object obj,
                     Locale locale)
Converts the specified object to a date and returns a formatted string representing that date in the specified Locale.

Parameters:
format - the formatting instructions
obj - the date object to be formatted
locale - the locale to be used when formatting
Returns:
the given date as a formatted string
See Also:
format(String format, Object obj, Locale locale, TimeZone timezone)

format

public String format(String format,
                     Object obj,
                     Locale locale,
                     TimeZone timezone)
Returns a formatted string representing the specified date, Locale, and TimeZone.

The specified format may be a standard style pattern ('full', 'long', 'medium', 'short', or 'default').

You may also specify that you want only the date or time portion be appending '_date' or '_time' respectively to the standard style pattern. (e.g. 'full_date' or 'long_time')

If the format fits neither of these patterns, then the output will be formatted according to the symbols defined by SimpleDateFormat:

   Symbol   Meaning                 Presentation        Example
   ------   -------                 ------------        -------
   G        era designator          (Text)              AD
   y        year                    (Number)            1996
   M        month in year           (Text & Number)     July & 07
   d        day in month            (Number)            10
   h        hour in am/pm (1~12)    (Number)            12
   H        hour in day (0~23)      (Number)            0
   m        minute in hour          (Number)            30
   s        second in minute        (Number)            55
   S        millisecond             (Number)            978
   E        day in week             (Text)              Tuesday
   D        day in year             (Number)            189
   F        day of week in month    (Number)            2 (2nd Wed in July)
   w        week in year            (Number)            27
   W        week in month           (Number)            2
   a        am/pm marker            (Text)              PM
   k        hour in day (1~24)      (Number)            24
   K        hour in am/pm (0~11)    (Number)            0
   z        time zone               (Text)              Pacific Standard Time
   '        escape for text         (Delimiter)
   ''       single quote            (Literal)           '

   Examples: "E, MMMM d" will result in "Tue, July 24"
             "EEE, M-d (H:m)" will result in "Tuesday, 7-24 (14:12)"
 

Parameters:
format - the custom or standard pattern to be used
obj - the date to format
locale - the Locale to format the date for
timezone - the TimeZone to be used when formatting
Returns:
a formatted string representing the specified date or null if the parameters are invalid
Since:
VelocityTools 1.1

format

public String format(String dateStyle,
                     String timeStyle,
                     Object obj)
Returns the specified date as a string formatted according to the specified date and/or time styles.

Parameters:
dateStyle - the style pattern for the date
timeStyle - the style pattern for the time
obj - the date to be formatted
Returns:
a formatted representation of the given date
Since:
VelocityTools 1.1
See Also:
format(String dateStyle, String timeStyle, Object obj, Locale locale, TimeZone timezone)

format

public String format(String dateStyle,
                     String timeStyle,
                     Object obj,
                     Locale locale)
Returns the specified date as a string formatted according to the specified Locale and date and/or time styles.

Parameters:
dateStyle - the style pattern for the date
timeStyle - the style pattern for the time
obj - the date to be formatted
locale - the Locale to be used for formatting the date
Returns:
a formatted representation of the given date
Since:
VelocityTools 1.1
See Also:
format(String dateStyle, String timeStyle, Object obj, Locale locale, TimeZone timezone)

format

public String format(String dateStyle,
                     String timeStyle,
                     Object obj,
                     Locale locale,
                     TimeZone timezone)
Returns the specified date as a string formatted according to the specified Locale and date and/or time styles.

Parameters:
dateStyle - the style pattern for the date
timeStyle - the style pattern for the time
obj - the date to be formatted
locale - the Locale to be used for formatting the date
timezone - the TimeZone the date should be formatted for
Returns:
a formatted representation of the given date
Since:
VelocityTools 1.1
See Also:
DateFormat, format(String dateStyle, String timeStyle, Object obj, Locale locale, TimeZone timezone)

getDateFormat

public DateFormat getDateFormat(String format,
                                Locale locale,
                                TimeZone timezone)
Returns a DateFormat instance for the specified format, Locale, and TimeZone. If the format specified is a standard style pattern, then a date-time instance will be returned with both the date and time styles set to the specified style. If it is a custom format, then a customized SimpleDateFormat will be returned.

Parameters:
format - the custom or standard formatting pattern to be used
locale - the Locale to be used
timezone - the TimeZone to be used
Returns:
an instance of DateFormat
Since:
VelocityTools 1.1
See Also:
SimpleDateFormat, DateFormat

getDateFormat

public DateFormat getDateFormat(String dateStyle,
                                String timeStyle,
                                Locale locale,
                                TimeZone timezone)
Returns a DateFormat instance for the specified date style, time style, Locale, and TimeZone.

Parameters:
dateStyle - the date style
timeStyle - the time style
locale - the Locale to be used
timezone - the TimeZone to be used
Returns:
an instance of DateFormat
Since:
VelocityTools 1.1
See Also:
getDateFormat(int timeStyle, int dateStyle, Locale locale, TimeZone timezone)

getDateFormat

@Deprecated
protected DateFormat getDateFormat(int dateStyle,
                                              int timeStyle,
                                              Locale locale,
                                              TimeZone timezone)
Deprecated. 

Returns a DateFormat instance for the specified time style, date style, Locale, and TimeZone.

Parameters:
dateStyle - the date style (date will be ignored if this is less than zero and the date style is not)
timeStyle - the time style (time will be ignored if this is less than zero and the date style is not)
locale - the Locale to be used
timezone - the TimeZone to be used
Returns:
an instance of DateFormat or null if an instance cannot be constructed with the given parameters
Since:
VelocityTools 1.1

getStyleAsInt

@Deprecated
protected int getStyleAsInt(String style)
Deprecated. 

Checks a string to see if it matches one of the standard DateFormat style patterns: FULL, LONG, MEDIUM, SHORT, or DEFAULT. If it does, it will return the integer constant for that pattern. If not, it will return -1.

Parameters:
style - the string to be checked
Returns:
the int identifying the style pattern
Since:
VelocityTools 1.1
See Also:
DateFormat

toDate

public Date toDate(Object obj)
Converts an object to an instance of Date using the format returned by FormatConfig.getFormat(),the Locale returned by LocaleConfig.getLocale(), and the TimeZone returned by getTimeZone() if the object is not already an instance of Date, Calendar, or Long.

Parameters:
obj - the date to convert
Returns:
the object as a Date or null if no conversion is possible

toDate

public Date toDate(String format,
                   Object obj)
Converts an object to an instance of Date using the specified format,the Locale returned by LocaleConfig.getLocale(), and the TimeZone returned by getTimeZone() if the object is not already an instance of Date, Calendar, or Long.

Parameters:
format - - the format the date is in
obj - - the date to convert
Returns:
the object as a Date or null if no conversion is possible
See Also:
toDate(String format, Object obj, Locale locale)

toDate

public Date toDate(String format,
                   Object obj,
                   Locale locale)
Converts an object to an instance of Date using the specified format and Locale if the object is not already an instance of Date, Calendar, or Long.

Parameters:
format - - the format the date is in
obj - - the date to convert
locale - - the Locale
Returns:
the object as a Date or null if no conversion is possible
See Also:
SimpleDateFormat.parse(java.lang.String, java.text.ParsePosition)

toDate

public Date toDate(String format,
                   Object obj,
                   Locale locale,
                   TimeZone timezone)
Converts an object to an instance of Date using the specified format, Locale, and TimeZone if the object is not already an instance of Date, Calendar, or Long.

Parameters:
format - - the format the date is in
obj - - the date to convert
locale - - the Locale
timezone - - the TimeZone
Returns:
the object as a Date or null if no conversion is possible
See Also:
getDateFormat(java.lang.String, java.util.Locale, java.util.TimeZone), SimpleDateFormat.parse(java.lang.String, java.text.ParsePosition)

toCalendar

public Calendar toCalendar(Object obj)
Converts an object to an instance of Calendar using the locale returned by LocaleConfig.getLocale() if necessary.

Parameters:
obj - the date to convert
Returns:
the converted date
See Also:
toCalendar(Object obj, Locale locale)

toCalendar

public Calendar toCalendar(Object obj,
                           Locale locale)
Converts an object to an instance of Calendar using the locale returned by LocaleConfig.getLocale() if necessary.

Parameters:
obj - the date to convert
locale - the locale used
Returns:
the converted date
See Also:
toDate(String format, Object obj, Locale locale), Calendar

toString

public String toString()
Overrides:
toString in class Object
Returns:
the result of getDate() formatted according to the result of FormatConfig.getFormat().
See Also:
format(String format, Object obj)


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