Nested Class Summary

Constructor Summary

Method Summary

Constructor Details

• MessageFormat

  public MessageFormat(String pattern)

  Constructs a MessageFormat for the defaultFORMAT locale and the specified pattern. The constructor first sets the locale, then parses the pattern and creates a list of subformats for the format elements contained in it. Patterns and their interpretation are specified in theclass description.

  Parameters:

  pattern - the pattern for this message format

  Throws:

  IllegalArgumentException - if the pattern is invalid

  NullPointerException - ifpattern isnull

• MessageFormat

  public MessageFormat(String pattern,Locale locale)

  Constructs a MessageFormat for the specified locale and pattern. The constructor first sets the locale, then parses the pattern and creates a list of subformats for the format elements contained in it. Patterns and their interpretation are specified in theclass description.

  Implementation Requirements:

  The default implementation throws aNullPointerException iflocale isnull either during the creation of theMessageFormat object or later whenformat() is called by aMessageFormat instance with a null locale and the implementation utilizes a locale-dependent subformat.

  Parameters:

  pattern - the pattern for this message format

  locale - the locale for this message format

  Throws:

  IllegalArgumentException - if the pattern is invalid

  NullPointerException - ifpattern isnull orlocale isnull and the implementation uses a locale-dependent subformat.

  Since:

  1.4

Method Details

• setLocale

  public void setLocale(Locale locale)

  Sets the locale to be used when creating or comparing subformats. This affects subsequent calls

  • to theapplyPattern andtoPattern methods if format elements specify a format type and therefore have the subformats created in theapplyPattern method, as well as
  • to theformat andformatToCharacterIterator methods if format elements do not specify a format type and therefore have the subformats created in the formatting methods.

  Subformats that have already been created are not affected.

  Parameters:

  locale - the locale to be used when creating or comparing subformats

• getLocale

  public Locale getLocale()

  Gets the locale that's used when creating or comparing subformats.

  Returns:

  the locale used when creating or comparing subformats

• applyPattern

  public void applyPattern(String pattern)

  Sets the pattern used by this message format. The method parses the pattern and creates a list of subformats for the format elements contained in it. Patterns and their interpretation are specified in theclass description.

  Parameters:

  pattern - the pattern for this message format

  Throws:

  IllegalArgumentException - if the pattern is invalid

  NullPointerException - ifpattern isnull

• toPattern

  public String toPattern()

  Returns a String pattern adhering to thepatterns section that represents the current state of thisMessageFormat. The string is constructed from internal information and therefore does not necessarily equal the previously applied pattern. The order ofFormatStyle matching is not guaranteed. That is, a FormatStyle produced may not be equivalent to the corresponding style passed, in the instance that multiple styles are equivalent.

  Implementation Requirements:

  The implementation inMessageFormat returns a string that, when passed to aMessageFormat() constructor orapplyPattern(), produces an instance that is semantically equivalent to this instance. If a subformat cannot be converted to a String pattern, theFormatType andFormatStyle will be omitted from theFormatElement.

  Returns:

  a String pattern adhering to thepatterns section that represents the current state of thisMessageFormat

• setFormatsByArgumentIndex

  public void setFormatsByArgumentIndex(Format[] newFormats)

  Sets the formats to use for the values passed intoformat methods or returned fromparse methods. The indices of elements innewFormats correspond to the argument indices used in the previously set pattern string. The order of formats innewFormats thus corresponds to the order of elements in thearguments array passed to theformat methods or the result array returned by theparse methods.

  If an argument index is used for more than one format element in the pattern string, then the corresponding new format is used for all such format elements. If an argument index is not used for any format element in the pattern string, then the corresponding new format is ignored. If fewer formats are provided than needed, then only the formats for argument indices less thannewFormats.length are replaced.

  Parameters:

  newFormats - the new formats to use

  Throws:

  NullPointerException - ifnewFormats is null

  Since:

  1.4

• setFormats

  public void setFormats(Format[] newFormats)

  Sets the formats to use for the format elements in the previously set pattern string. The order of formats innewFormats corresponds to the order of format elements in the pattern string.

  If more formats are provided than needed by the pattern string, the remaining ones are ignored. If fewer formats are provided than needed, then only the firstnewFormats.length formats are replaced.

  Since the order of format elements in a pattern string often changes during localization, it is generally better to use thesetFormatsByArgumentIndex method, which assumes an order of formats corresponding to the order of elements in thearguments array passed to theformat methods or the result array returned by theparse methods.

  Parameters:

  newFormats - the new formats to use

  Throws:

  NullPointerException - ifnewFormats is null

• setFormatByArgumentIndex

  public void setFormatByArgumentIndex(int argumentIndex,Format newFormat)

  Sets the format to use for the format elements within the previously set pattern string that use the given argument index. The argument index is part of the format element definition and represents an index into thearguments array passed to theformat methods or the result array returned by theparse methods.

  If the argument index is used for more than one format element in the pattern string, then the new format is used for all such format elements. If the argument index is not used for any format element in the pattern string, then the new format is ignored.

  Parameters:

  argumentIndex - the argument index for which to use the new format

  newFormat - the new format to use

  Since:

  1.4

• setFormat

  public void setFormat(int formatElementIndex,Format newFormat)

  Sets the format to use for the format element with the given format element index within the previously set pattern string. The format element index is the zero-based number of the format element counting from the start of the pattern string.

  Since the order of format elements in a pattern string often changes during localization, it is generally better to use thesetFormatByArgumentIndex method, which accesses format elements based on the argument index they specify.

  Parameters:

  formatElementIndex - the index of a format element within the pattern

  newFormat - the format to use for the specified format element

  Throws:

  ArrayIndexOutOfBoundsException - ifformatElementIndex is equal to or larger than the number of format elements in the pattern string

• getFormatsByArgumentIndex

  public Format[] getFormatsByArgumentIndex()

  Gets the formats used for the values passed intoformat methods or returned fromparse methods. The indices of elements in the returned array correspond to the argument indices used in the previously set pattern string. The order of formats in the returned array thus corresponds to the order of elements in thearguments array passed to theformat methods or the result array returned by theparse methods.

  If an argument index is used for more than one format element in the pattern string, then the format used for the last such format element is returned in the array. If an argument index is not used for any format element in the pattern string, then null is returned in the array.

  Returns:

  the formats used for the arguments within the pattern

  Since:

  1.4

• getFormats

  public Format[] getFormats()

  Gets the formats used for the format elements in the previously set pattern string. The order of formats in the returned array corresponds to the order of format elements in the pattern string.

  Since the order of format elements in a pattern string often changes during localization, it's generally better to use thegetFormatsByArgumentIndex method, which assumes an order of formats corresponding to the order of elements in thearguments array passed to theformat methods or the result array returned by theparse methods.

  Returns:

  the formats used for the format elements in the pattern

• format

  public final StringBuffer format(Object[] arguments,StringBuffer result,FieldPosition pos)

  Formats an array of objects and appends theMessageFormat's pattern, with format elements replaced by the formatted objects, to the providedStringBuffer.

  The text substituted for the individual format elements is derived from the current subformat of the format element and thearguments element at the format element's argument index as indicated by the first matching line of the following table. An argument isunavailable ifarguments isnull or has fewer than argumentIndex+1 elements.

  Examples of subformat, argument, and formatted text

  Subformat	Argument	Formatted Text
  any	unavailable	"{" + argumentIndex + "}"
  	null	"null"
  instanceof ChoiceFormat	any	subformat.format(argument).indexOf('{') >= 0 ? (new MessageFormat(subformat.format(argument), getLocale())).format(argument) : subformat.format(argument)
  != null	any	subformat.format(argument)
  null	instanceof Number	NumberFormat.getInstance(getLocale()).format(argument)
  	instanceof Date	DateFormat.getDateTimeInstance(DateFormat.SHORT, DateFormat.SHORT, getLocale()).format(argument)
  	instanceof String	argument
  	any	argument.toString()

  Ifpos is non-null, and refers toField.ARGUMENT, the location of the first formatted string will be returned.

  Parameters:

  arguments - an array of objects to be formatted and substituted.

  result - where text is appended.

  pos - keeps track on the position of the first replaced argument in the output string.

  Returns:

  the string buffer passed in asresult, with formatted text appended

  Throws:

  IllegalArgumentException - if an argument in thearguments array is not of the type expected by the format element(s) that use it.

  NullPointerException - ifresult isnull or if theMessageFormat instance that calls this method has locale set to null, and the implementation uses a locale-dependent subformat.

• format

  public static String format(String pattern,Object... arguments)

  Creates a MessageFormat with the given pattern and uses it to format the given arguments. This method returns a string that would be equal to the string returned by

  (newMessageFormat(pattern)).format(arguments, new StringBuffer(), null).toString()

  Parameters:

  pattern - the pattern string

  arguments - object(s) to format

  Returns:

  the formatted string

  Throws:

  IllegalArgumentException - if the pattern is invalid, or if an argument in thearguments array is not of the type expected by the format element(s) that use it.

  NullPointerException - ifpattern isnull

• format

  public final StringBuffer format(Object arguments,StringBuffer result,FieldPosition pos)

  Formats an array of objects and appends theMessageFormat's pattern, with format elements replaced by the formatted objects, to the providedStringBuffer. This is equivalent to

  format((Object[]) arguments, result, pos)

  Specified by:

  format in class Format

  Parameters:

  arguments - an array of objects to be formatted and substituted.

  result - where text is appended.

  pos - keeps track on the position of the first replaced argument in the output string.

  Returns:

  the string buffer passed in astoAppendTo, with formatted text appended

  Throws:

  IllegalArgumentException - if an argument in thearguments array is not of the type expected by the format element(s) that use it.

  NullPointerException - ifresult isnull or if theMessageFormat instance that calls this method has locale set to null, and the implementation uses a locale-dependent subformat.

• formatToCharacterIterator

  public AttributedCharacterIterator formatToCharacterIterator(Object arguments)

  Formats an array of objects and inserts them into theMessageFormat's pattern, producing anAttributedCharacterIterator. You can use the returnedAttributedCharacterIterator to build the resulting String, as well as to determine information about the resulting String.

  The text of the returnedAttributedCharacterIterator is the same that would be returned by

  format(arguments, new StringBuffer(), null).toString()

  In addition, theAttributedCharacterIterator contains at least attributes indicating where text was generated from an argument in thearguments array. The keys of these attributes are of typeMessageFormat.Field, their values areInteger objects indicating the index in thearguments array of the argument from which the text was generated.

  The attributes/value from the underlyingFormat instances thatMessageFormat uses will also be placed in the resultingAttributedCharacterIterator. This allows you to not only find where an argument is placed in the resulting String, but also which fields it contains in turn.

  Overrides:

  formatToCharacterIterator in class Format

  Parameters:

  arguments - an array of objects to be formatted and substituted.

  Returns:

  AttributedCharacterIterator describing the formatted value.

  Throws:

  NullPointerException - ifarguments is null.

  IllegalArgumentException - if an argument in thearguments array is not of the type expected by the format element(s) that use it.

  Since:

  1.4

• parse

  public Object[] parse(String source,ParsePosition pos)

  Parses the string.

  Caveats: The parse may fail in a number of circumstances. For example:

  • If one of the arguments does not occur in the pattern.
  • If the format of an argument loses information, such as with a choice format where a large number formats to "many".
  • Does not yet handle recursion (where the substituted strings contain {n} references.)
  • Will not always find a match (or the correct match) if some part of the parse is ambiguous. For example, if the pattern "{1},{2}" is used with the string arguments {"a,b", "c"}, it will format as "a,b,c". When the result is parsed, it will return {"a", "b,c"}.
  • If a single argument is parsed more than once in the string, then the later parse wins.

  When the parse fails, use ParsePosition.getErrorIndex() to find out where in the string the parsing failed. The returned error index is the starting offset of the sub-patterns that the string is comparing with. For example, if the parsing string "AAA {0} BBB" is comparing against the pattern "AAD {0} BBB", the error index is 0. When an error occurs, the call to this method will return null. If the source is null, return an empty array.

  Parameters:

  source - the string to parse

  pos - the parse position

  Returns:

  an array of parsed objects

  Throws:

  NullPointerException - ifpos isnull for a non-nullsource string.

• parse

  public Object[] parse(String source) throwsParseException

  Parses text from the beginning of the given string to produce an object array. The method may not use the entire text of the given string.

  See theparse(String, ParsePosition) method for more information on message parsing.

  Parameters:

  source - AString whose beginning should be parsed.

  Returns:

  AnObject array parsed from the string.

  Throws:

  ParseException - if the beginning of the specified string cannot be parsed.

• parseObject

  public Object parseObject(String source,ParsePosition pos)

  Parses text from a string to produce an object array.

  The method attempts to parse text starting at the index given bypos. If parsing succeeds, then the index ofpos 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 object array is returned. The updatedpos can be used to indicate the starting point for the next call to this method. If an error occurs, then the index ofpos is not changed, the error index ofpos is set to the index of the character where the error occurred, and null is returned.

  See theparse(String, ParsePosition) method for more information on message parsing.

  Specified by:

  parseObject in class Format

  Parameters:

  source - AString, part of which should be parsed.

  pos - AParsePosition object with index and error index information as described above.

  Returns:

  AnObject array parsed from the string. In case of error, returns null.

  Throws:

  NullPointerException - ifpos is null.

• clone

  public Object clone()

  Creates and returns a copy of this object.

  Overrides:

  clone in class Format

  Returns:

  a clone of this instance.

  See Also:

  • Cloneable

• equals

  public boolean equals(Object obj)

  Compares the specified object with thisMessageFormat for equality. Returns true if the object is also aMessageFormat and the two formats would format any value the same.

  Overrides:

  equals in class Object

  Implementation Requirements:

  This method performs an equality check with a notion of class identity based ongetClass(), rather thaninstanceof. Therefore, in the equals methods in subclasses, no instance of this class should compare as equal to an instance of a subclass.

  Parameters:

  obj - object to be compared for equality

  Returns:

  true if the specified object is equal to thisMessageFormat

  See Also:

  • Object.equals(Object)

• hashCode

  public int hashCode()

  Returns the hash code value for thisMessageFormat.

  Overrides:

  hashCode in class Object

  Implementation Requirements:

  This method calculates the hash code value using the value returned bytoPattern().

  Returns:

  the hash code value for thisMessageFormat

  See Also:

  • Object.hashCode()

• toString

  public String toString()

  Returns a string identifying thisMessageFormat, for debugging.

  Overrides:

  toString in class Object

  Returns:

  a string identifying thisMessageFormat, for debugging