MessageFormat

See also:

• Locale
• Format
• NumberFormat
• DecimalFormat
• DecimalFormatSymbols
• ChoiceFormat
• DateFormat
• SimpleDateFormat

MessageFormat

public MessageFormat (String pattern)

Constructs a MessageFormat for the default FORMAT 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 the class description.

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 the class description.

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 the class description.

clone

public Object clone ()

Creates and returns a copy of this object.

equals

public boolean equals (Object obj)

Equality comparison between two message format objects

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 is equivalent to

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

format

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

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

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

If pos is non-null, and refers to Field.ARGUMENT, the location of the first formatted string will be returned.

format

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

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

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

formatToCharacterIterator

public AttributedCharacterIterator formatToCharacterIterator (Object arguments)

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

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

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

In addition, the AttributedCharacterIterator contains at least attributes indicating where text was generated from an argument in the arguments array. The keys of these attributes are of type MessageFormat.Field, their values are Integer objects indicating the index in the arguments array of the argument from which the text was generated.

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

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 the getFormatsByArgumentIndex method, which assumes an order of formats corresponding to the order of elements in the arguments array passed to the format methods or the result array returned by the parse methods.

getFormatsByArgumentIndex

public Format[] getFormatsByArgumentIndex ()

Gets the formats used for the values passed into format methods or returned from parse 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 the arguments array passed to the format methods or the result array returned by the parse 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.

getLocale

public Locale getLocale ()

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

hashCode

public int hashCode ()

Generates a hash code for the message format object.

parse

public Object[] parse (String source)

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 the parse(java.lang.String, java.text.ParsePosition) method for more information on message parsing.

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.

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 by pos. If parsing succeeds, then the index of pos 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 updated pos can be used to indicate the starting point for the next call to this method. If an error occurs, then the index of pos is not changed, the error index of pos is set to the index of the character where the error occurred, and null is returned.

See the parse(java.lang.String, java.text.ParsePosition) method for more information on message parsing.

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 the setFormatByArgumentIndex method, which accesses format elements based on the argument index they specify.

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 the arguments array passed to the format methods or the result array returned by the parse 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.

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 in newFormats 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 first newFormats.length formats are replaced.

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

setFormatsByArgumentIndex

public void setFormatsByArgumentIndex (Format[] newFormats)

Sets the formats to use for the values passed into format methods or returned from parse methods. The indices of elements in newFormats correspond to the argument indices used in the previously set pattern string. The order of formats in newFormats thus corresponds to the order of elements in the arguments array passed to the format methods or the result array returned by the parse 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 than newFormats.length are replaced.

setLocale

public void setLocale (Locale locale)

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

• to the applyPattern and toPattern methods if format elements specify a format type and therefore have the subformats created in the applyPattern method, as well as
• to the format and formatToCharacterIterator methods if format elements do not specify a format type and therefore have the subformats created in the formatting methods.

toPattern

public String toPattern ()

Returns a pattern representing the current state of the message format. The string is constructed from internal information and therefore does not necessarily equal the previously applied pattern.