Package com.ibm.icu.text

Class DateTimePatternGenerator

  • All Implemented Interfaces:
    Freezable<DateTimePatternGenerator>, Cloneable
    public class DateTimePatternGenerator
extends Object
implements Freezable<DateTimePatternGenerator>, Cloneable
    This class provides flexible generation of date format patterns, like "yy-MM-dd". The user can build up the generator by adding successive patterns. Once that is done, a query can be made using a "skeleton", which is a pattern which just includes the desired fields and lengths. The generator will return the "best fit" pattern corresponding to that skeleton.

    The main method people will use is getBestPattern(String skeleton), since normally this class is pre-built with data from a particular locale. However, generators can be built directly from other data as well.

    Status:
    Stable ICU 3.6.

    • Constructor Detail

      • DateTimePatternGenerator

        protected DateTimePatternGenerator()
        Only for use by subclasses
        Status:
        Stable ICU 3.6.

    • Method Detail

      • getEmptyInstance

        public static DateTimePatternGenerator getEmptyInstance()
        Create empty generator, to be constructed with addPattern(...) etc.
        Status:
        Stable ICU 3.6.

      • getInstance

        public static DateTimePatternGenerator getInstance​(ULocale uLocale)
        Construct a flexible generator according to data for a given locale.
        Parameters:
        uLocale - The locale to pass.
        Status:
        Stable ICU 3.6.

      • getInstance

        public static DateTimePatternGenerator getInstance​(Locale locale)
        Construct a flexible generator according to data for a given locale.
        Parameters:
        locale - The Locale to pass.
        Status:
        Stable ICU 54.

      • getFrozenInstance

        @Deprecated
public static DateTimePatternGenerator getFrozenInstance​(ULocale uLocale)
        Deprecated.
        This API is ICU internal only.
        Construct a frozen instance of DateTimePatternGenerator for a given locale. This method returns a cached frozen instance of DateTimePatternGenerator, so less expensive than the regular factory method.
        Parameters:
        uLocale - The locale to pass.
        Returns:
        A frozen DateTimePatternGenerator.
        Status:
        Internal. This API is ICU internal only.

      • getInstanceNoStdPat

        @Deprecated
public static DateTimePatternGenerator getInstanceNoStdPat​(ULocale uLocale)
        Deprecated.
        This API is ICU internal only.
        Construct a non-frozen instance of DateTimePatternGenerator for a given locale that skips using the standard date and time patterns. Because this is different than the normal instance for the locale, it does not set or use the cache.
        Parameters:
        uLocale - The locale to pass.
        Status:
        Internal. This API is ICU internal only.

      • getDefaultHourFormatChar

        @Deprecated
public char getDefaultHourFormatChar()
        Deprecated.
        This API is ICU internal only.
        Status:
        Internal. This API is ICU internal only.

      • setDefaultHourFormatChar

        @Deprecated
public void setDefaultHourFormatChar​(char defaultHourFormatChar)
        Deprecated.
        This API is ICU internal only.
        Status:
        Internal. This API is ICU internal only.

      • getAppendFormatNumber

        @Deprecated
public static int getAppendFormatNumber​(com.ibm.icu.impl.UResource.Key key)
        Deprecated.
        This API is ICU internal only.
        Status:
        Internal. This API is ICU internal only.

      • getAppendFormatNumber

        @Deprecated
public static int getAppendFormatNumber​(String string)
        Deprecated.
        This API is ICU internal only.
        Status:
        Internal. This API is ICU internal only.

      • getBestPattern

        public String getBestPattern​(String skeleton)
        Return the best pattern matching the input skeleton. It is guaranteed to have all of the fields in the skeleton.

        Example code:

         import java.util.Date;

 import com.ibm.icu.text.DateFormat;
 import com.ibm.icu.text.DateTimePatternGenerator;
 import com.ibm.icu.text.SimpleDateFormat;
 import com.ibm.icu.util.GregorianCalendar;
 import com.ibm.icu.util.TimeZone;
 import com.ibm.icu.util.ULocale;
 ...
 final String[] skeletons = {
         "yQQQQ", // year + full name of quarter, i.e., 4th quarter 1999
         "yMMMM", // year + full name of month, i.e., October 1999
         "MMMMd", // full name of month + day of the month, i.e., October 25
         "hhmm",  // 12-hour-cycle format, i.e., 1:32 PM
         "jjmm"   // preferred hour format for the given locale, i.e., 24-hour-cycle format for fr_FR
 };
 final ULocale[] locales = {
         new ULocale ("en_US"),
         new ULocale ("fr_FR"),
         new ULocale ("zh_CN"),
 };
 DateTimePatternGenerator dtfg = null;
 Date date= new GregorianCalendar(1999,9,13,23,58,59).getTime();
 System.out.printf("%-20s%-35s%-35s%-35s\n\n", "Skeleton", "en_US", "fr_FR","zh_CN");
 for (String skeleton:skeletons) {
     System.out.printf("%-20s", skeleton);
     for (ULocale locale:locales) {
         // create a DateTimePatternGenerator instance for given locale
         dtfg = DateTimePatternGenerator.getInstance(locale);
         // use getBestPattern method to get the best pattern for the given skeleton
         String pattern = dtfg.getBestPattern(skeleton);
         // Constructs a SimpleDateFormat with the best pattern generated above and the given locale
         SimpleDateFormat sdf = new SimpleDateFormat(pattern, locale);
         // Get the format of the given date
         System.out.printf("%-35s",sdf.format(date));
     }
     System.out.println("\n");
 }
 /** output of the sample code:
  *************************************************************************************************************
    Skeleton            en_US                              fr_FR                              zh_CN
    yQQQQ               4th quarter 1999                   4e trimestre 1999                  1999年第四季度
    yMMMM               October 1999                       octobre 1999                       1999年10月
    MMMMd               October 13                         13 octobre                         10月13日
    hhmm                11:58 PM                           11:58 PM                           下午11:58
    jjmm                11:58 PM                           23:58                              下午11:58
  **************************************************************************************************************/
 // Use DateTime.getPatternInstance to produce the same Date/Time format with predefined constant field value
 final String[] dtfskeleton = {
         DateFormat.YEAR_QUARTER, // year + full name of quarter, i.e., 4th quarter 1999
         DateFormat.YEAR_MONTH,   // year + full name of month, i.e., October 1999
         DateFormat.MONTH_DAY     // full name of month + day of the month, i.e., October 25
 };
 System.out.printf("%-20s%-35s%-35s%-35s\n\n", "Skeleton", "en_US", "fr_FR","zh_CN");
 for (String skeleton:dtfskeleton) {
     System.out.printf("%-20s", skeleton);
     for (ULocale locale:locales) {
         // Use DateFormat.getPatternInstance to get the date/time format for the locale,
         // and apply the format to the given date
         String df=DateFormat.getPatternInstance(skeleton,locale).format(date);
         System.out.printf("%-35s",df);
     }
     System.out.println("\n");
 }

 /** output of the sample code:
  ************************************************************************************************************
  Skeleton            en_US                              fr_FR                              zh_CN
  yQQQQ               4th quarter 1999                   4e trimestre 1999                  1999年第四季度
  yMMMM               October 1999                       octobre 1999                       1999年10月
  MMMMd               October 13                         13 octobre                         10月13日
  ************************************************************************************************************/
        Parameters:
        skeleton - The skeleton is a pattern containing only the variable fields. For example, "MMMdd" and "mmhh" are skeletons.
        Returns:
        Best pattern matching the input skeleton.
        Status:
        Stable ICU 3.6.

      • getBestPattern

        public String getBestPattern​(String skeleton,
                             int options)
        Return the best pattern matching the input skeleton. It is guaranteed to have all of the fields in the skeleton.
        Parameters:
        skeleton - The skeleton is a pattern containing only the variable fields. For example, "MMMdd" and "mmhh" are skeletons.
        options - MATCH_xxx options for forcing the length of specified fields in the returned pattern to match those in the skeleton (when this would not happen otherwise). For default behavior, use MATCH_NO_OPTIONS.
        Returns:
        Best pattern matching the input skeleton (and options).
        Status:
        Stable ICU 4.4.

      • addPattern

        public DateTimePatternGenerator addPattern​(String pattern,
                                           boolean override,
                                           DateTimePatternGenerator.PatternInfo returnInfo)
        Adds a pattern to the generator. If the pattern has the same skeleton as an existing pattern, and the override parameter is set, then the previous value is overridden. Otherwise, the previous value is retained. In either case, the conflicting information is returned in PatternInfo.

        Note that single-field patterns (like "MMM") are automatically added, and don't need to be added explicitly!

        Example code:

         Date date= new GregorianCalendar(1999,9,13,23,58,59).getTime();
 ULocale locale = ULocale.FRANCE;
 // Create an DateTimePatternGenerator instance for the given locale
 DateTimePatternGenerator gen = DateTimePatternGenerator.getInstance(locale);
 SimpleDateFormat format = new SimpleDateFormat(gen.getBestPattern("MMMMddHmm"), locale);
 DateTimePatternGenerator.PatternInfo returnInfo = new DateTimePatternGenerator.PatternInfo();
 // Add '. von' to the existing pattern
 gen.addPattern("dd'. von' MMMM", true, returnInfo);
 // Apply the new pattern
 format.applyPattern(gen.getBestPattern("MMMMddHmm"));
 System.out.println("New Pattern for FRENCH: "+format.toPattern());
 System.out.println("Date Time in new Pattern: "+format.format(date));

 /** output of the sample code:
  **************************************************************************************************
  New Pattern for FRENCH: dd. 'von' MMMM HH:mm
  Date Time in new Pattern: 13. von octobre 23:58
  *************************************************************************************************/
        Parameters:
        pattern - Pattern to add.
        override - When existing values are to be overridden use true, otherwise use false.
        returnInfo - Returned information.
        Status:
        Stable ICU 3.6.

      • addPatternWithSkeleton

        @Deprecated
public DateTimePatternGenerator addPatternWithSkeleton​(String pattern,
                                                       String skeletonToUse,
                                                       boolean override,
                                                       DateTimePatternGenerator.PatternInfo returnInfo)
        Deprecated.
        This API is ICU internal only.
        addPatternWithSkeleton: If skeletonToUse is specified, then an availableFormats entry is being added. In this case: 1. We pass that skeleton to DateTimeMatcher().set instead of having it derive a skeleton from the pattern. 2. If the new entry's skeleton or basePattern does match an existing entry but that entry also had a skeleton specified (i.e. it was also from availableFormats), then the new entry does not override it regardless of the value of the override parameter. This prevents later availableFormats entries from a parent locale overriding earlier ones from the actual specified locale. However, availableFormats entries *should* override entries with matching skeleton whose skeleton was derived (i.e. entries derived from the standard date/time patters for the specified locale). 3. When adding the pattern (skeleton2pattern.put, basePattern_pattern.put), we set a field to indicate that the added entry had a specified skeleton.
        Status:
        Internal. This API is ICU internal only.

      • getSkeleton

        public String getSkeleton​(String pattern)
        Utility to return a unique skeleton from a given pattern. For example, both "MMM-dd" and "dd/MMM" produce the skeleton "MMMdd".
        Parameters:
        pattern - Input pattern, such as "dd/MMM"
        Returns:
        skeleton, such as "MMMdd"
        Status:
        Stable ICU 3.6.

      • getSkeletonAllowingDuplicates

        @Deprecated
public String getSkeletonAllowingDuplicates​(String pattern)
        Deprecated.
        This API is ICU internal only.
        Same as getSkeleton, but allows duplicates
        Parameters:
        pattern - Input pattern, such as "dd/MMM"
        Returns:
        skeleton, such as "MMMdd"
        Status:
        Internal. This API is ICU internal only.

      • getCanonicalSkeletonAllowingDuplicates

        @Deprecated
public String getCanonicalSkeletonAllowingDuplicates​(String pattern)
        Deprecated.
        This API is ICU internal only.
        Same as getSkeleton, but allows duplicates and returns a string using canonical pattern chars
        Parameters:
        pattern - Input pattern, such as "ccc, d LLL"
        Returns:
        skeleton, such as "MMMEd"
        Status:
        Internal. This API is ICU internal only.

      • getBaseSkeleton

        public String getBaseSkeleton​(String pattern)
        Utility to return a unique base skeleton from a given pattern. This is the same as the skeleton, except that differences in length are minimized so as to only preserve the difference between string and numeric form. So for example, both "MMM-dd" and "d/MMM" produce the skeleton "MMMd" (notice the single d).
        Parameters:
        pattern - Input pattern, such as "dd/MMM"
        Returns:
        skeleton, such as "MMMdd"
        Status:
        Stable ICU 3.6.

      • getSkeletons

        public Map<String,​String> getSkeletons​(Map<String,​String> result)
        Return a list of all the skeletons (in canonical form) from this class, and the patterns that they map to.
        Parameters:
        result - an output Map in which to place the mapping from skeleton to pattern. If you want to see the internal order being used, supply a LinkedHashMap. If the input value is null, then a LinkedHashMap is allocated.

        Issue: an alternate API would be to just return a list of the skeletons, and then have a separate routine to get from skeleton to pattern.

        Returns:
        the input Map containing the values.
        Status:
        Stable ICU 3.6.

      • getBaseSkeletons

        public Set<String> getBaseSkeletons​(Set<String> result)
        Return a list of all the base skeletons (in canonical form) from this class
        Status:
        Stable ICU 3.6.

      • replaceFieldTypes

        public String replaceFieldTypes​(String pattern,
                                String skeleton)
        Adjusts the field types (width and subtype) of a pattern to match what is in a skeleton. That is, if you supply a pattern like "d-M H:m", and a skeleton of "MMMMddhhmm", then the input pattern is adjusted to be "dd-MMMM hh:mm". This is used internally to get the best match for the input skeleton, but can also be used externally.

        Example code:

         Date date= new GregorianCalendar(1999,9,13,23,58,59).getTime();
 TimeZone zone = TimeZone.getTimeZone("Europe/Paris");
 ULocale locale = ULocale.FRANCE;
 DateTimePatternGenerator gen = DateTimePatternGenerator.getInstance(locale);
 SimpleDateFormat format = new SimpleDateFormat("EEEE d MMMM y HH:mm:ss zzzz",locale);
 format.setTimeZone(zone);
 String pattern = format.toPattern();
 System.out.println("Pattern before replacement:");
 System.out.println(pattern);
 System.out.println("Date/Time format in fr_FR:");
 System.out.println(format.format(date));
 // Replace zone "zzzz" in the pattern with "vvvv"
 String newPattern = gen.replaceFieldTypes(pattern, "vvvv");
 // Apply the new pattern
 format.applyPattern(newPattern);
 System.out.println("Pattern after replacement:");
 System.out.println(newPattern);
 System.out.println("Date/Time format in fr_FR:");
 System.out.println(format.format(date));

 /** output of the sample code:
 ***************************************************************************************************
  Pattern before replacement:
  EEEE d MMMM y HH:mm:ss zzzz
  Date/Time format in fr_FR:
  jeudi 14 octobre 1999 05:58:59 heure avancée d’Europe centrale
  Pattern after replacement:
  EEEE d MMMM y HH:mm:ss vvvv
  Date/Time format in fr_FR:
  jeudi 14 octobre 1999 05:58:59 heure de l’Europe centrale

 **************************************************************************************************/
        Parameters:
        pattern - input pattern
        skeleton - For the pattern to match to.
        Returns:
        pattern adjusted to match the skeleton fields widths and subtypes.
        Status:
        Stable ICU 3.6.

      • replaceFieldTypes

        public String replaceFieldTypes​(String pattern,
                                String skeleton,
                                int options)
        Adjusts the field types (width and subtype) of a pattern to match what is in a skeleton. That is, if you supply a pattern like "d-M H:m", and a skeleton of "MMMMddhhmm", then the input pattern is adjusted to be "dd-MMMM hh:mm". This is used internally to get the best match for the input skeleton, but can also be used externally.
        Parameters:
        pattern - input pattern
        skeleton - For the pattern to match to.
        options - MATCH_xxx options for forcing the length of specified fields in the returned pattern to match those in the skeleton (when this would not happen otherwise). For default behavior, use MATCH_NO_OPTIONS.
        Returns:
        pattern adjusted to match the skeleton fields widths and subtypes.
        Status:
        Stable ICU 4.4.

      • setDateTimeFormat

        public void setDateTimeFormat​(String dateTimeFormat)
        The date time format is a message format pattern used to compose date and time patterns. The default value is "{1} {0}", where {1} will be replaced by the date pattern and {0} will be replaced by the time pattern.

        This is used when the input skeleton contains both date and time fields, but there is not a close match among the added patterns. For example, suppose that this object was created by adding "dd-MMM" and "hh:mm", and its datetimeFormat is the default "{1} {0}". Then if the input skeleton is "MMMdhmm", there is not an exact match, so the input skeleton is broken up into two components "MMMd" and "hmm". There are close matches for those two skeletons, so the result is put together with this pattern, resulting in "d-MMM h:mm". There are four DateTimeFormats in a DateTimePatternGenerator object, corresponding to date styles DateFormat.FULL..DateFormat.SHORT. This method sets all of them to the specified pattern. To set them individually, see setDateTimeFormat(int style, ...).

        Parameters:
        dateTimeFormat - message format pattern, where {1} will be replaced by the date pattern and {0} will be replaced by the time pattern.
        Status:
        Stable ICU 3.6.

      • getDateTimeFormat

        public String getDateTimeFormat()
        Getter corresponding to setDateTimeFormat. There are four DateTimeFormats in a DateTimePatternGenerator object, corresponding to date styles DateFormat.FULL..DateFormat.SHORT. This method gets the style for DateFormat.MEDIUM (the default). To get them individually, see getDateTimeFormat(int style).
        Returns:
        pattern
        Status:
        Stable ICU 3.6.

      • setDateTimeFormat

        public void setDateTimeFormat​(int style,
                              String dateTimeFormat)
        dateTimeFormats are message patterns used to compose combinations of date and time patterns. There are four length styles, corresponding to the inferred style of the date pattern: - DateFormat.FULL (for date pattern with weekday and long month), else - DateFormat.LONG (for a date pattern with long month), else - DateFormat.MEDIUM (for a date pattern with abbreviated month), else - DateFormat.SHORT (for any other date pattern). For details on dateTimeFormats, see https://www.unicode.org/reports/tr35/tr35-dates.html#dateTimeFormats. The default pattern in the root locale for all styles is "{1} {0}".
        Parameters:
        style - one of DateFormat.FULL..DateFormat.SHORT. An exception will be thrown if out of range.
        dateTimeFormat - the new dateTimeFormat to set for the specified style
        Status:
        Stable ICU 71.

      • getDateTimeFormat

        public String getDateTimeFormat​(int style)
        Getter corresponding to setDateTimeFormat.
        Parameters:
        style - one of DateFormat.FULL..DateFormat.SHORT. An exception will be thrown if out of range.
        Returns:
        the current dateTimeFormat for the specified style.
        Status:
        Stable ICU 71.

      • setDecimal

        public void setDecimal​(String decimal)
        The decimal value is used in formatting fractions of seconds. If the skeleton contains fractional seconds, then this is used with the fractional seconds. For example, suppose that the input pattern is "hhmmssSSSS", and the best matching pattern internally is "H:mm:ss", and the decimal string is ",". Then the resulting pattern is modified to be "H:mm:ss,SSSS"
        Parameters:
        decimal - The decimal to set to.
        Status:
        Stable ICU 3.6.

      • getDecimal

        public String getDecimal()
        Getter corresponding to setDecimal.
        Returns:
        string corresponding to the decimal point
        Status:
        Stable ICU 3.6.

      • getRedundants

        @Deprecated
public Collection<String> getRedundants​(Collection<String> output)
        Deprecated.
        This API is ICU internal only.
        Redundant patterns are those which if removed, make no difference in the resulting getBestPattern values. This method returns a list of them, to help check the consistency of the patterns used to build this generator.
        Parameters:
        output - stores the redundant patterns that are removed. To get these in internal order, supply a LinkedHashSet. If null, a collection is allocated.
        Returns:
        the collection with added elements.
        Status:
        Internal. This API is ICU internal only.

      • setAppendItemFormat

        public void setAppendItemFormat​(int field,
                                String value)
        An AppendItem format is a pattern used to append a field if there is no good match. For example, suppose that the input skeleton is "GyyyyMMMd", and there is no matching pattern internally, but there is a pattern matching "yyyyMMMd", say "d-MM-yyyy". Then that pattern is used, plus the G. The way these two are conjoined is by using the AppendItemFormat for G (era). So if that value is, say "{0}, {1}" then the final resulting pattern is "d-MM-yyyy, G".

        There are actually three available variables: {0} is the pattern so far, {1} is the element we are adding, and {2} is the name of the element.

        This reflects the way that the CLDR data is organized.

        Parameters:
        field - such as ERA
        value - pattern, such as "{0}, {1}"
        Status:
        Stable ICU 3.6.

      • getAppendItemFormat

        public String getAppendItemFormat​(int field)
        Getter corresponding to setAppendItemFormats. Values below 0 or at or above TYPE_LIMIT are illegal arguments.
        Parameters:
        field - The index to retrieve the append item formats.
        Returns:
        append pattern for field
        Status:
        Stable ICU 3.6.

      • setAppendItemName

        public void setAppendItemName​(int field,
                              String value)
        Sets the names of fields, eg "era" in English for ERA. These are only used if the corresponding AppendItemFormat is used, and if it contains a {2} variable.

        This reflects the way that the CLDR data is organized.

        Parameters:
        field - Index of the append item names.
        value - The value to set the item to.
        Status:
        Stable ICU 3.6.

      • getAppendItemName

        public String getAppendItemName​(int field)
        Getter corresponding to setAppendItemName. Values below 0 or at or above TYPE_LIMIT are illegal arguments. Note: The more general method for getting date/time field display names is getFieldDisplayName.
        Parameters:
        field - The index to get the append item name.
        Returns:
        name for field
        See Also:
        getFieldDisplayName(int, DisplayWidth)
        Status:
        Stable ICU 3.6.

      • getDefaultHourCycle

        public DateFormat.HourCycle getDefaultHourCycle()
        Return the default hour cycle.
        Status:
        Stable ICU 67.

      • getFieldDisplayName

        public String getFieldDisplayName​(int field,
                                  DateTimePatternGenerator.DisplayWidth width)
        The general interface to get a display name for a particular date/time field, in one of several possible display widths.
        Parameters:
        field - The field type, such as ERA.
        width - The desired DisplayWidth, such as DisplayWidth.ABBREVIATED.
        Returns:
        The display name for the field
        Status:
        Stable ICU 61.

      • isSingleField

        @Deprecated
public static boolean isSingleField​(String skeleton)
        Deprecated.
        This API is ICU internal only.
        Determines whether a skeleton contains a single field
        Parameters:
        skeleton - The skeleton to determine if it contains a single field.
        Returns:
        true or not
        Status:
        Internal. This API is ICU internal only.

      • clone

        public DateTimePatternGenerator clone()
        Returns a copy of this DateTimePatternGenerator object.
        Overrides:
        clone in class Object
        Returns:
        A copy of this DateTimePatternGenerator object.
        Status:
        Stable ICU 3.6.

      • skeletonsAreSimilar

        @Deprecated
public boolean skeletonsAreSimilar​(String id,
                                   String skeleton)
        Deprecated.
        This API is ICU internal only.
        Used by CLDR tooling; not in ICU4C. Note, this will not work correctly with normal skeletons, since fields that should be related in the two skeletons being compared - like EEE and ccc, or y and U - will not be sorted in the same relative place as each other when iterating over both TreeSets being compare, using TreeSet's "natural" code point ordering (this could be addressed by initializing the TreeSet with a comparator that compares fields first by their index from getCanonicalIndex()). However if comparing canonical skeletons from getCanonicalSkeletonAllowingDuplicates it will be OK regardless, since in these skeletons all fields are normalized to the canonical pattern char for those fields - M or L to M, E or c to E, y or U to y, etc. - so corresponding fields will sort in the same way for both TreeMaps.
        Status:
        Internal. This API is ICU internal only.

      • getFields

        @Deprecated
public String getFields​(String pattern)
        Deprecated.
        This API is ICU internal only.
        internal routine
        Parameters:
        pattern - The pattern that is passed.
        Returns:
        field value
        Status:
        Internal. This API is ICU internal only.