public MessageFormat(String pattern) 
{
        this.locale = Locale.getDefault(Locale.Category.FORMAT);
        applyPattern(pattern);
}

Constructs a MessageFormat for the default 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.

Parameters:

pattern - the pattern for this message format

Throws:

IllegalArgumentException - if the pattern is invalid

exception: IllegalArgumentException - if the pattern is invalid

 public MessageFormat(String pattern,
    Locale locale) 
{
        this.locale = locale;
        applyPattern(pattern);
}

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.

Parameters:

pattern - the pattern for this message format

locale - the locale for this message format

Throws:

IllegalArgumentException - if the pattern is invalid

exception: IllegalArgumentException - if the pattern is invalid

since: 1.4 -

 public  void applyPattern(String pattern) 
{
            StringBuilder[] segments = new StringBuilder[4];
            // Allocate only segments[SEG_RAW] here. The rest are
            // allocated on demand.
            segments[SEG_RAW] = new StringBuilder();
            int part = SEG_RAW;
            int formatNumber = 0;
            boolean inQuote = false;
            int braceStack = 0;
            maxOffset = -1;
            for (int i = 0; i <  pattern.length(); ++i) {
                char ch = pattern.charAt(i);
                if (part == SEG_RAW) {
                    if (ch == '\'') {
                        if (i + 1 <  pattern.length()
                            && pattern.charAt(i+1) == '\'') {
                            segments[part].append(ch);  // handle doubles
                            ++i;
                        } else {
                            inQuote = !inQuote;
                        }
                    } else if (ch == '{' && !inQuote) {
                        part = SEG_INDEX;
                        if (segments[SEG_INDEX] == null) {
                            segments[SEG_INDEX] = new StringBuilder();
                        }
                    } else {
                        segments[part].append(ch);
                    }
                } else  {
                    if (inQuote) {              // just copy quotes in parts
                        segments[part].append(ch);
                        if (ch == '\'') {
                            inQuote = false;
                        }
                    } else {
                        switch (ch) {
                        case ',':
                            if (part <  SEG_MODIFIER) {
                                if (segments[++part] == null) {
                                    segments[part] = new StringBuilder();
                                }
                            } else {
                                segments[part].append(ch);
                            }
                            break;
                        case '{':
                            ++braceStack;
                            segments[part].append(ch);
                            break;
                        case '}':
                            if (braceStack == 0) {
                                part = SEG_RAW;
                                makeFormat(i, formatNumber, segments);
                                formatNumber++;
                                // throw away other segments
                                segments[SEG_INDEX] = null;
                                segments[SEG_TYPE] = null;
                                segments[SEG_MODIFIER] = null;
                            } else {
                                --braceStack;
                                segments[part].append(ch);
                            }
                            break;
                        case ' ':
                            // Skip any leading space chars for SEG_TYPE.
                            if (part != SEG_TYPE || segments[SEG_TYPE].length()  > 0) {
                                segments[part].append(ch);
                            }
                            break;
                        case '\'':
                            inQuote = true;
                            // fall through, so we keep quotes in other parts
                        default:
                            segments[part].append(ch);
                            break;
                        }
                    }
                }
            }
            if (braceStack == 0 && part != 0) {
                maxOffset = -1;
                throw new IllegalArgumentException("Unmatched braces in the pattern.");
            }
            this.pattern = segments[0].toString();
}

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.

 public Object clone() 
{
        MessageFormat other = (MessageFormat) super.clone();
        // clone arrays. Can't do with utility because of bug in Cloneable
        other.formats = (Format[]) formats.clone(); // shallow clone
        for (int i = 0; i <  formats.length; ++i) {
            if (formats[i] != null)
                other.formats[i] = (Format)formats[i].clone();
        }
        // for primitives or immutables, shallow clone is enough
        other.offsets = (int[]) offsets.clone();
        other.argumentNumbers = (int[]) argumentNumbers.clone();
        return other;
}

Creates and returns a copy of this object.

 public boolean equals(Object obj) 
{
        if (this == obj)                      // quick check
            return true;
        if (obj == null || getClass() != obj.getClass())
            return false;
        MessageFormat other = (MessageFormat) obj;
        return (maxOffset == other.maxOffset
                && pattern.equals(other.pattern)
                && ((locale != null && locale.equals(other.locale))
                 || (locale == null && other.locale == null))
                && Arrays.equals(offsets,other.offsets)
                && Arrays.equals(argumentNumbers,other.argumentNumbers)
                && Arrays.equals(formats,other.formats));
}

Equality comparison between two message format objects

 public static String format(String pattern,
    Object arguments) 
{
        MessageFormat temp = new MessageFormat(pattern);
        return temp.format(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()

 public final StringBuffer format(Object[] arguments,
    StringBuffer result,
    FieldPosition pos) 
{
        return subformat(arguments, result, pos, null);
}

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.

Subformat	Argument	Formatted Text
any	unavailable	"{" + argumentIndex + "}"
any	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)
null	instanceof Date	DateFormat.getDateTimeInstance(DateFormat.SHORT, DateFormat.SHORT, getLocale()).format(argument)
null	instanceof String	argument
null	any	argument.toString()

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

 public final StringBuffer format(Object arguments,
    StringBuffer result,
    FieldPosition pos) 
{
        return subformat((Object[]) arguments, result, pos, null);
}

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)

 public AttributedCharacterIterator formatToCharacterIterator(Object arguments) 
{
        StringBuffer result = new StringBuffer();
        ArrayList iterators = new ArrayList();
        if (arguments == null) {
            throw new NullPointerException(
                   "formatToCharacterIterator must be passed non-null object");
        }
        subformat((Object[]) arguments, result, null, iterators);
        if (iterators.size() == 0) {
            return createAttributedCharacterIterator("");
        }
        return createAttributedCharacterIterator(
                     (AttributedCharacterIterator[])iterators.toArray(
                     new AttributedCharacterIterator[iterators.size()]));
}

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.

 public Format[] getFormats() 
{
        Format[] resultArray = new Format[maxOffset + 1];
        System.arraycopy(formats, 0, resultArray, 0, maxOffset + 1);
        return resultArray;
}

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.

 public Format[] getFormatsByArgumentIndex() 
{
        int maximumArgumentNumber = -1;
        for (int i = 0; i < = maxOffset; i++) {
            if (argumentNumbers[i]  > maximumArgumentNumber) {
                maximumArgumentNumber = argumentNumbers[i];
            }
        }
        Format[] resultArray = new Format[maximumArgumentNumber + 1];
        for (int i = 0; i < = maxOffset; i++) {
            resultArray[argumentNumbers[i]] = formats[i];
        }
        return resultArray;
}

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.

 public Locale getLocale() 
{
        return locale;
}

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

 public int hashCode() 
{
        return pattern.hashCode(); // enough for reasonable distribution
}

Generates a hash code for the message format object.

 public Object[] parse(String source) throws ParseException 
{
        ParsePosition pos  = new ParsePosition(0);
        Object[] result = parse(source, pos);
        if (pos.index == 0)  // unchanged, returned object is null
            throw new ParseException("MessageFormat parse error!", pos.errorIndex);
        return result;
}

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

 public Object[] parse(String source,
    ParsePosition pos) 
{
        if (source == null) {
            Object[] empty = {};
            return empty;
        }
        int maximumArgumentNumber = -1;
        for (int i = 0; i < = maxOffset; i++) {
            if (argumentNumbers[i]  > maximumArgumentNumber) {
                maximumArgumentNumber = argumentNumbers[i];
            }
        }
        Object[] resultArray = new Object[maximumArgumentNumber + 1];
        int patternOffset = 0;
        int sourceOffset = pos.index;
        ParsePosition tempStatus = new ParsePosition(0);
        for (int i = 0; i < = maxOffset; ++i) {
            // match up to format
            int len = offsets[i] - patternOffset;
            if (len == 0 || pattern.regionMatches(patternOffset,
                                                  source, sourceOffset, len)) {
                sourceOffset += len;
                patternOffset += len;
            } else {
                pos.errorIndex = sourceOffset;
                return null; // leave index as is to signal error
            }
            // now use format
            if (formats[i] == null) {   // string format
                // if at end, use longest possible match
                // otherwise uses first match to intervening string
                // does NOT recursively try all possibilities
                int tempLength = (i != maxOffset) ? offsets[i+1] : pattern.length();
                int next;
                if (patternOffset  >= tempLength) {
                    next = source.length();
                }else{
                    next = source.indexOf(pattern.substring(patternOffset, tempLength),
                                          sourceOffset);
                }
                if (next <  0) {
                    pos.errorIndex = sourceOffset;
                    return null; // leave index as is to signal error
                } else {
                    String strValue= source.substring(sourceOffset,next);
                    if (!strValue.equals("{"+argumentNumbers[i]+"}"))
                        resultArray[argumentNumbers[i]]
                            = source.substring(sourceOffset,next);
                    sourceOffset = next;
                }
            } else {
                tempStatus.index = sourceOffset;
                resultArray[argumentNumbers[i]]
                    = formats[i].parseObject(source,tempStatus);
                if (tempStatus.index == sourceOffset) {
                    pos.errorIndex = sourceOffset;
                    return null; // leave index as is to signal error
                }
                sourceOffset = tempStatus.index; // update
            }
        }
        int len = pattern.length() - patternOffset;
        if (len == 0 || pattern.regionMatches(patternOffset,
                                              source, sourceOffset, len)) {
            pos.index = sourceOffset + len;
        } else {
            pos.errorIndex = sourceOffset;
            return null; // leave index as is to signal error
        }
        return resultArray;
}

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.

 public Object parseObject(String source,
    ParsePosition pos) 
{
        return parse(source, 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(String, ParsePosition) method for more information on message parsing.

 public  void setFormat(int formatElementIndex,
    Format newFormat) 
{
        formats[formatElementIndex] = 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.

 public  void setFormatByArgumentIndex(int argumentIndex,
    Format newFormat) 
{
        for (int j = 0; j < = maxOffset; j++) {
            if (argumentNumbers[j] == argumentIndex) {
                formats[j] = 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.

 public  void setFormats(Format[] newFormats) 
{
        int runsToCopy = newFormats.length;
        if (runsToCopy  > maxOffset + 1) {
            runsToCopy = maxOffset + 1;
        }
        for (int i = 0; i <  runsToCopy; i++) {
            formats[i] = newFormats[i];
        }
}

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.

 public  void setFormatsByArgumentIndex(Format[] newFormats) 
{
        for (int i = 0; i < = maxOffset; i++) {
            int j = argumentNumbers[i];
            if (j <  newFormats.length) {
                formats[i] = newFormats[j];
            }
        }
}

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.

 public  void setLocale(Locale locale) 
{
        this.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.
Subformats that have already been created are not affected.

 public String toPattern() 
{
        // later, make this more extensible
        int lastOffset = 0;
        StringBuilder result = new StringBuilder();
        for (int i = 0; i < = maxOffset; ++i) {
            copyAndFixQuotes(pattern, lastOffset, offsets[i], result);
            lastOffset = offsets[i];
            result.append('{').append(argumentNumbers[i]);
            Format fmt = formats[i];
            if (fmt == null) {
                // do nothing, string format
            } else if (fmt instanceof NumberFormat) {
                if (fmt.equals(NumberFormat.getInstance(locale))) {
                    result.append(",number");
                } else if (fmt.equals(NumberFormat.getCurrencyInstance(locale))) {
                    result.append(",number,currency");
                } else if (fmt.equals(NumberFormat.getPercentInstance(locale))) {
                    result.append(",number,percent");
                } else if (fmt.equals(NumberFormat.getIntegerInstance(locale))) {
                    result.append(",number,integer");
                } else {
                    if (fmt instanceof DecimalFormat) {
                        result.append(",number,").append(((DecimalFormat)fmt).toPattern());
                    } else if (fmt instanceof ChoiceFormat) {
                        result.append(",choice,").append(((ChoiceFormat)fmt).toPattern());
                    } else {
                        // UNKNOWN
                    }
                }
            } else if (fmt instanceof DateFormat) {
                int index;
                for (index = MODIFIER_DEFAULT; index <  DATE_TIME_MODIFIERS.length; index++) {
                    DateFormat df = DateFormat.getDateInstance(DATE_TIME_MODIFIERS[index],
                                                               locale);
                    if (fmt.equals(df)) {
                        result.append(",date");
                        break;
                    }
                    df = DateFormat.getTimeInstance(DATE_TIME_MODIFIERS[index],
                                                    locale);
                    if (fmt.equals(df)) {
                        result.append(",time");
                        break;
                    }
                }
                if (index  >= DATE_TIME_MODIFIERS.length) {
                    if (fmt instanceof SimpleDateFormat) {
                        result.append(",date,").append(((SimpleDateFormat)fmt).toPattern());
                    } else {
                        // UNKNOWN
                    }
                } else if (index != MODIFIER_DEFAULT) {
                    result.append(',').append(DATE_TIME_MODIFIER_KEYWORDS[index]);
                }
            } else {
                //result.append(", unknown");
            }
            result.append('}');
        }
        copyAndFixQuotes(pattern, lastOffset, pattern.length(), result);
        return result.toString();
}

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.