类 DateTool

直接已知子类:
ComparisonDateTool

@DefaultKey("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.

从以下版本开始:
VelocityTools 1.0
版本:
$Revision: 719489 $ $Date: 2008-11-20 22:05:11 -0800 (Thu, 20 Nov 2008) $
作者:
Nathan Bubna
  • 字段详细资料

  • 构造器详细资料

    • DateTool

      public DateTool()
  • 方法详细资料

    • 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.
      覆盖:
      configure 在类中 FormatConfig
    • setTimeZone

      protected void setTimeZone(TimeZone timezone)
    • getSystemTime

      public static final long getSystemTime()
      返回:
      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()
      返回:
      the system's current time as a Date
    • getSystemCalendar

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

      public TimeZone getTimeZone()
      Returns the configured TimeZone. Default value is from TimeZone.getDefault().
      返回:
      the configured TimeZone
    • getDate

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

      返回:
      a Calendar instance created using the results of getTimeZone() and LocaleConfig.getLocale().
      另请参阅:
    • getYear

      public Integer getYear()
      Returns the year value of the date returned by getCalendar().
      从以下版本开始:
      VelocityTools 1.2
    • getYear

      public Integer getYear(Object date)
      Returns the year value of the specified date.
      从以下版本开始:
      VelocityTools 1.2
    • getMonth

      public Integer getMonth()
      Returns the month value of the date returned by getCalendar().
      从以下版本开始:
      VelocityTools 1.2
    • getMonth

      public Integer getMonth(Object date)
      Returns the month value of the specified date.
      从以下版本开始:
      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.
      从以下版本开始:
      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.
      从以下版本开始:
      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.
      从以下版本开始:
      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.
      参数:
      field - the corresponding Integer value or String name of the desired value
      date - the date/calendar from which the field value will be taken
      从以下版本开始:
      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.
      参数:
      field - the int for the desired field (e.g. Calendar.MONTH)
      date - the date/calendar from which the field value will be taken
      从以下版本开始:
      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'))
      参数:
      format - the formatting instructions
      返回:
      a formatted representation of the date returned by getDate()
      从以下版本开始:
      VelocityTools 1.1
      另请参阅:
    • 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.
      参数:
      dateStyle - the style pattern for the date
      timeStyle - the style pattern for the time
      返回:
      a formatted representation of the date returned by getDate()
      从以下版本开始:
      VelocityTools 1.1
      另请参阅:
    • 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().
      参数:
      obj - the date object to be formatted
      返回:
      the specified date formatted as a string
      从以下版本开始:
      VelocityTools 1.1
      另请参阅:
    • 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().
      参数:
      format - the formatting instructions
      obj - the date object to be formatted
      返回:
      a formatted string for this locale representing the specified date or null if the parameters are invalid
      另请参阅:
    • 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.
      参数:
      format - the formatting instructions
      obj - the date object to be formatted
      locale - the locale to be used when formatting
      返回:
      the given date as a formatted string
      另请参阅:
    • 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)"
       

      参数:
      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
      返回:
      a formatted string representing the specified date or null if the parameters are invalid
      从以下版本开始:
      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.
      参数:
      dateStyle - the style pattern for the date
      timeStyle - the style pattern for the time
      obj - the date to be formatted
      返回:
      a formatted representation of the given date
      从以下版本开始:
      VelocityTools 1.1
      另请参阅:
    • 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.
      参数:
      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
      返回:
      a formatted representation of the given date
      从以下版本开始:
      VelocityTools 1.1
      另请参阅:
    • 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.
      参数:
      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
      返回:
      a formatted representation of the given date
      从以下版本开始:
      VelocityTools 1.1
      另请参阅:
    • 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.
      参数:
      format - the custom or standard formatting pattern to be used
      locale - the Locale to be used
      timezone - the TimeZone to be used
      返回:
      an instance of DateFormat
      从以下版本开始:
      VelocityTools 1.1
      另请参阅:
    • 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.
      参数:
      dateStyle - the date style
      timeStyle - the time style
      locale - the Locale to be used
      timezone - the TimeZone to be used
      返回:
      an instance of DateFormat
      从以下版本开始:
      VelocityTools 1.1
      另请参阅:
    • getDateFormat

      @Deprecated protected DateFormat getDateFormat(int dateStyle, int timeStyle, Locale locale, TimeZone timezone)
      已过时。
      Returns a DateFormat instance for the specified time style, date style, Locale, and TimeZone.
      参数:
      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
      返回:
      an instance of DateFormat or null if an instance cannot be constructed with the given parameters
      从以下版本开始:
      VelocityTools 1.1
    • getStyleAsInt

      @Deprecated protected int getStyleAsInt(String style)
      已过时。
      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.
      参数:
      style - the string to be checked
      返回:
      the int identifying the style pattern
      从以下版本开始:
      VelocityTools 1.1
      另请参阅:
    • 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.
      参数:
      obj - the date to convert
      返回:
      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.
      参数:
      format - - the format the date is in
      obj - - the date to convert
      返回:
      the object as a Date or null if no conversion is possible
      另请参阅:
    • 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.
      参数:
      format - - the format the date is in
      obj - - the date to convert
      locale - - the Locale
      返回:
      the object as a Date or null if no conversion is possible
      另请参阅:
    • 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.
      参数:
      format - - the format the date is in
      obj - - the date to convert
      locale - - the Locale
      timezone - - the TimeZone
      返回:
      the object as a Date or null if no conversion is possible
      另请参阅:
    • toCalendar

      public Calendar toCalendar(Object obj)
      Converts an object to an instance of Calendar using the locale returned by LocaleConfig.getLocale() if necessary.
      参数:
      obj - the date to convert
      返回:
      the converted date
      另请参阅:
    • 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.
      参数:
      obj - the date to convert
      locale - the locale used
      返回:
      the converted date
      另请参阅:
    • toString

      public String toString()
      覆盖:
      toString 在类中 Object
      返回:
      the result of getDate() formatted according to the result of FormatConfig.getFormat().
      另请参阅: