MessageFormat provides a means to produce concatenated
* messages in a language-neutral way. Use this to construct messages
* displayed for end users.
*
*
* MessageFormat takes a set of objects, formats them, then
* inserts the formatted strings into the pattern at the appropriate places.
*
*
* Note:
* MessageFormat differs from the other Format
* classes in that you create a MessageFormat object with one
* of its constructors (not with a getInstance style factory
* method). The factory methods aren't necessary because MessageFormat
* itself doesn't implement locale specific behavior. Any locale specific
* behavior is defined by the pattern that you provide as well as the
* subformats used for inserted arguments.
*
*
MessageFormat uses patterns of the following form:
*
* MessageFormatPattern:
* String
* MessageFormatPattern FormatElement String
*
* FormatElement:
* { ArgumentIndex }
* { ArgumentIndex , FormatType }
* { ArgumentIndex , FormatType , FormatStyle }
*
* FormatType: one of
* number date time choice
*
* FormatStyle:
* short
* medium
* long
* full
* integer
* currency
* percent
* SubformatPattern
* Within a String, a pair of single quotes can be used to
* quote any arbitrary characters except single quotes. For example,
* pattern string "'{0}'" represents string
* "{0}", not a FormatElement. A single quote itself
* must be represented by doubled single quotes {@code ''} throughout a
* String. For example, pattern string "'{''}'" is
* interpreted as a sequence of '{ (start of quoting and a
* left curly brace), '' (a single quote), and
* }' (a right curly brace and end of quoting),
* not '{' and '}' (quoted left and
* right curly braces): representing string "{'}",
* not "{}".
*
*
A SubformatPattern is interpreted by its corresponding
* subformat, and subformat-dependent pattern rules apply. For example,
* pattern string "{1,number,$'#',##}"
* (SubformatPattern with underline) will produce a number format
* with the pound-sign quoted, with a result such as: {@code
* "$#31,45"}. Refer to each {@code Format} subclass documentation for
* details.
*
*
Any unmatched quote is treated as closed at the end of the given * pattern. For example, pattern string {@code "'{0}"} is treated as * pattern {@code "'{0}'"}. * *
Any curly braces within an unquoted pattern must be balanced. For
* example, "ab {0} de" and "ab '}' de" are
* valid patterns, but "ab {0'}' de", "ab } de"
* and "''{''" are not.
*
*
* The ArgumentIndex value is a non-negative integer written * using the digits {@code '0'} through {@code '9'}, and represents an index into the * {@code arguments} array passed to the {@code format} methods * or the result array returned by the {@code parse} methods. *
* The FormatType and FormatStyle values are used to create * a {@code Format} instance for the format element. The following * table shows how the values map to {@code Format} instances. Combinations not * shown in the table are illegal. A SubformatPattern must * be a valid pattern string for the {@code Format} subclass used. * *
| FormatType * | FormatStyle * | Subformat Created * |
|---|---|---|
| (none) * | (none) * | null
* |
number
* | (none) * | {@link NumberFormat#getInstance(Locale) NumberFormat.getInstance}{@code (getLocale())} * |
integer
* | {@link NumberFormat#getIntegerInstance(Locale) NumberFormat.getIntegerInstance}{@code (getLocale())} * | |
currency
* | {@link NumberFormat#getCurrencyInstance(Locale) NumberFormat.getCurrencyInstance}{@code (getLocale())} * | |
percent
* | {@link NumberFormat#getPercentInstance(Locale) NumberFormat.getPercentInstance}{@code (getLocale())} * | |
| SubformatPattern * | {@code new} {@link DecimalFormat#DecimalFormat(String,DecimalFormatSymbols) DecimalFormat}{@code (subformatPattern,} {@link DecimalFormatSymbols#getInstance(Locale) DecimalFormatSymbols.getInstance}{@code (getLocale()))} * | |
date
* | (none) * | {@link DateFormat#getDateInstance(int,Locale) DateFormat.getDateInstance}{@code (}{@link DateFormat#DEFAULT}{@code , getLocale())} * |
short
* | {@link DateFormat#getDateInstance(int,Locale) DateFormat.getDateInstance}{@code (}{@link DateFormat#SHORT}{@code , getLocale())} * | |
medium
* | {@link DateFormat#getDateInstance(int,Locale) DateFormat.getDateInstance}{@code (}{@link DateFormat#DEFAULT}{@code , getLocale())} * | |
long
* | {@link DateFormat#getDateInstance(int,Locale) DateFormat.getDateInstance}{@code (}{@link DateFormat#LONG}{@code , getLocale())} * | |
full
* | {@link DateFormat#getDateInstance(int,Locale) DateFormat.getDateInstance}{@code (}{@link DateFormat#FULL}{@code , getLocale())} * | |
| SubformatPattern * | {@code new} {@link SimpleDateFormat#SimpleDateFormat(String,Locale) SimpleDateFormat}{@code (subformatPattern, getLocale())} * | |
time
* | (none) * | {@link DateFormat#getTimeInstance(int,Locale) DateFormat.getTimeInstance}{@code (}{@link DateFormat#DEFAULT}{@code , getLocale())} * |
short
* | {@link DateFormat#getTimeInstance(int,Locale) DateFormat.getTimeInstance}{@code (}{@link DateFormat#SHORT}{@code , getLocale())} * | |
medium
* | {@link DateFormat#getTimeInstance(int,Locale) DateFormat.getTimeInstance}{@code (}{@link DateFormat#DEFAULT}{@code , getLocale())} * | |
long
* | {@link DateFormat#getTimeInstance(int,Locale) DateFormat.getTimeInstance}{@code (}{@link DateFormat#LONG}{@code , getLocale())} * | |
full
* | {@link DateFormat#getTimeInstance(int,Locale) DateFormat.getTimeInstance}{@code (}{@link DateFormat#FULL}{@code , getLocale())} * | |
| SubformatPattern * | {@code new} {@link SimpleDateFormat#SimpleDateFormat(String,Locale) SimpleDateFormat}{@code (subformatPattern, getLocale())} * | |
choice
* | SubformatPattern * | {@code new} {@link ChoiceFormat#ChoiceFormat(String) ChoiceFormat}{@code (subformatPattern)} * |
* Here are some examples of usage. * In real internationalized programs, the message format pattern and other * static strings will, of course, be obtained from resource bundles. * Other parameters will be dynamically determined at runtime. *
* The first example uses the static method MessageFormat.format,
* which internally creates a MessageFormat for one-time use:
*
* int planet = 7;
* String event = "a disturbance in the Force";
*
* String result = MessageFormat.format(
* "At {1,time} on {1,date}, there was {2} on planet {0,number,integer}.",
* planet, new Date(), event);
* * ** At 12:30 PM on Jul 3, 2053, there was a disturbance in the Force on planet 7. *
* The following example creates a MessageFormat instance that
* can be used repeatedly:
*
* int fileCount = 1273;
* String diskName = "MyDisk";
* Object[] testArgs = {new Long(fileCount), diskName};
*
* MessageFormat form = new MessageFormat(
* "The disk \"{1}\" contains {0} file(s).");
*
* System.out.println(form.format(testArgs));
* fileCount:
* * ** The disk "MyDisk" contains 0 file(s). * The disk "MyDisk" contains 1 file(s). * The disk "MyDisk" contains 1,273 file(s). *
* For more sophisticated patterns, you can use a ChoiceFormat
* to produce correct forms for singular and plural:
*
* MessageFormat form = new MessageFormat("The disk \"{1}\" contains {0}.");
* double[] filelimits = {0,1,2};
* String[] filepart = {"no files","one file","{0,number} files"};
* ChoiceFormat fileform = new ChoiceFormat(filelimits, filepart);
* form.setFormatByArgumentIndex(0, fileform);
*
* int fileCount = 1273;
* String diskName = "MyDisk";
* Object[] testArgs = {new Long(fileCount), diskName};
*
* System.out.println(form.format(testArgs));
* fileCount:
* * ** The disk "MyDisk" contains no files. * The disk "MyDisk" contains one file. * The disk "MyDisk" contains 1,273 files. *
* You can create the ChoiceFormat programmatically, as in the
* above example, or by using a pattern. See {@link ChoiceFormat}
* for more information.
*
{@code
* form.applyPattern(
* "There {0,choice,0#are no files|1#is one file|1
* Note: As we see above, the string produced
* by a ChoiceFormat in MessageFormat is treated as special;
* occurrences of '{' are used to indicate subformats, and cause recursion.
* If you create both a MessageFormat and ChoiceFormat
* programmatically (instead of using the string patterns), then be careful not to
* produce a format that recurses on itself, which will cause an infinite loop.
*
* When a single argument is parsed more than once in the string, the last match * will be the final result of the parsing. For example, *
* MessageFormat mf = new MessageFormat("{0,number,#.##}, {0,number,#.#}");
* Object[] objs = {new Double(3.1415)};
* String result = mf.format( objs );
* // result now equals "3.14, 3.1"
* objs = null;
* objs = mf.parse(result, new ParsePosition(0));
* // objs now equals {new Double(3.1)}
* * Likewise, parsing with a {@code MessageFormat} object using patterns containing * multiple occurrences of the same argument would return the last match. For * example, *
* MessageFormat mf = new MessageFormat("{0}, {0}, {0}");
* String forParsing = "x, y, z";
* Object[] objs = mf.parse(forParsing, new ParsePosition(0));
* // result now equals {new String("z")}
* * Message formats are not synchronized. * It is recommended to create separate format instances for each thread. * If multiple threads access a format concurrently, it must be synchronized * externally. * * @see java.util.Locale * @see Format * @see NumberFormat * @see DecimalFormat * @see DecimalFormatSymbols * @see ChoiceFormat * @see DateFormat * @see SimpleDateFormat * * @author Mark Davis */ public class MessageFormat extends Format { private static final long serialVersionUID = 6479157306784022952L; /** * Constructs a MessageFormat for the default * {@link java.util.Locale.Category#FORMAT 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. * * @param pattern the pattern for this message format * @exception IllegalArgumentException if the pattern is invalid */ public MessageFormat(String pattern) { this.locale = Locale.getDefault(Locale.Category.FORMAT); 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. * * @param pattern the pattern for this message format * @param locale the locale for this message format * @exception IllegalArgumentException if the pattern is invalid * @since 1.4 */ public MessageFormat(String pattern, Locale locale) { this.locale = locale; applyPattern(pattern); } /** * Sets the locale to be used when creating or comparing subformats. * This affects subsequent calls *
applyPattern method, as well as
* format and
* {@link #formatToCharacterIterator formatToCharacterIterator} methods
* if format elements do not specify a format type and therefore have
* the subformats created in the formatting methods.
* 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.
*
* @param newFormats the new formats to use
* @exception NullPointerException if newFormats is null
* @since 1.4
*/
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 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
* {@link #setFormatsByArgumentIndex 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.
*
* @param newFormats the new formats to use
* @exception NullPointerException if newFormats is null
*/
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 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. * * @param argumentIndex the argument index for which to use the new format * @param newFormat the new format to use * @since 1.4 */ 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 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
* {@link #setFormatByArgumentIndex setFormatByArgumentIndex}
* method, which accesses format elements based on the argument
* index they specify.
*
* @param formatElementIndex the index of a format element within the pattern
* @param newFormat the format to use for the specified format element
* @exception ArrayIndexOutOfBoundsException if {@code formatElementIndex} is equal to or
* larger than the number of format elements in the pattern string
*/
public void setFormat(int formatElementIndex, Format newFormat) {
if (formatElementIndex > maxOffset) {
throw new ArrayIndexOutOfBoundsException(maxOffset, formatElementIndex);
}
formats[formatElementIndex] = newFormat;
}
/**
* 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. * * @return the formats used for the arguments within the pattern * @since 1.4 */ 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 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
* {@link #getFormatsByArgumentIndex 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.
*
* @return the formats used for the format elements in the pattern
*/
public Format[] getFormats() {
Format[] resultArray = new Format[maxOffset + 1];
System.arraycopy(formats, 0, resultArray, 0, maxOffset + 1);
return resultArray;
}
/**
* 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 ?
* |
!= 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.
*
* @param arguments an array of objects to be formatted and substituted.
* @param result where text is appended.
* @param pos On input: an alignment field, if desired.
* On output: the offsets of the alignment field.
* @return the string buffer passed in as {@code result}, with formatted
* text appended
* @exception IllegalArgumentException if an argument in the
* arguments array is not of the type
* expected by the format element(s) that use it.
*/
public final StringBuffer format(Object[] arguments, StringBuffer result,
FieldPosition pos)
{
return subformat(arguments, result, pos, null);
}
/**
* Creates a MessageFormat with the given pattern and uses it
* to format the given arguments. This is equivalent to
*
* (new {@link #MessageFormat(String) MessageFormat}(pattern)).{@link #format(java.lang.Object[], java.lang.StringBuffer, java.text.FieldPosition) format}(arguments, new StringBuffer(), null).toString()
*
*
* @param pattern the pattern string
* @param arguments object(s) to format
* @return the formatted string
* @exception IllegalArgumentException if the pattern is invalid,
* or if an argument in the arguments array
* is not of the type expected by the format element(s)
* that use it.
*/
public static String format(String pattern, Object ... arguments) {
MessageFormat temp = new MessageFormat(pattern);
return temp.format(arguments);
}
// Overrides
/**
* 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
*
* {@link #format(java.lang.Object[], java.lang.StringBuffer, java.text.FieldPosition) format}((Object[]) arguments, result, pos)
*
*
* @param arguments an array of objects to be formatted and substituted.
* @param result where text is appended.
* @param pos On input: an alignment field, if desired.
* On output: the offsets of the alignment field.
* @exception IllegalArgumentException if an argument in the
* arguments array is not of the type
* expected by the format element(s) that use it.
*/
public final StringBuffer format(Object arguments, StringBuffer result,
FieldPosition pos)
{
return subformat((Object[]) arguments, result, pos, null);
}
/**
* 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
*
* {@link #format(java.lang.Object[], java.lang.StringBuffer, java.text.FieldPosition) 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 Caveats: The parse may fail in a number of circumstances.
* For example:
*
* See the {@link #parse(String, ParsePosition)} method for more information
* on message parsing.
*
* @param source A
* The method attempts to parse text starting at the index given by
*
* See the {@link #parse(String, ParsePosition)} method for more information
* on message parsing.
*
* @param source A 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.
*
* @param arguments an array of objects to be formatted and substituted.
* @return AttributedCharacterIterator describing the formatted value.
* @exception NullPointerException if arguments is null.
* @exception IllegalArgumentException if an argument in the
* arguments array is not of the type
* expected by the format element(s) that use it.
* @since 1.4
*/
public AttributedCharacterIterator formatToCharacterIterator(Object arguments) {
StringBuffer result = new StringBuffer();
ArrayList
*
* 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.
*
* @param source the string to parse
* @param pos the parse position
* @return an array of parsed objects
*/
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 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.
* String whose beginning should be parsed.
* @return An Object array parsed from the string.
* @exception ParseException if the beginning of the specified string
* cannot be parsed.
*/
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 a string to produce an object array.
* 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.
* String, part of which should be parsed.
* @param pos A ParsePosition object with index and error
* index information as described above.
* @return An Object array parsed from the string. In case of
* error, returns null.
* @exception NullPointerException if pos is null.
*/
public Object parseObject(String source, ParsePosition pos) {
return parse(source, pos);
}
/**
* Creates and returns a copy of this object.
*
* @return a clone of this instance.
*/
public Object clone() {
MessageFormat other = (MessageFormat) super.clone();
// clone arrays. Can't do with utility because of bug in Cloneable
other.formats = 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 = offsets.clone();
other.argumentNumbers = argumentNumbers.clone();
return other;
}
/**
* Equality comparison between two message format objects
*/
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));
}
/**
* Generates a hash code for the message format object.
*/
public int hashCode() {
return pattern.hashCode(); // enough for reasonable distribution
}
/**
* Defines constants that are used as attribute keys in the
* AttributedCharacterIterator returned
* from MessageFormat.formatToCharacterIterator.
*
* @since 1.4
*/
public static class Field extends Format.Field {
// Proclaim serial compatibility with 1.4 FCS
private static final long serialVersionUID = 7899943957617360810L;
/**
* Creates a Field with the specified name.
*
* @param name Name of the attribute
*/
protected Field(String name) {
super(name);
}
/**
* Resolves instances being deserialized to the predefined constants.
*
* @throws InvalidObjectException if the constant could not be
* resolved.
* @return resolved MessageFormat.Field constant
*/
protected Object readResolve() throws InvalidObjectException {
if (this.getClass() != MessageFormat.Field.class) {
throw new InvalidObjectException("subclass didn't correctly implement readResolve");
}
return ARGUMENT;
}
//
// The constants
//
/**
* Constant identifying a portion of a message that was generated
* from an argument passed into formatToCharacterIterator.
* The value associated with the key will be an Integer
* indicating the index in the arguments array of the
* argument from which the text was generated.
*/
public final static Field ARGUMENT =
new Field("message argument field");
}
// ===========================privates============================
/**
* The locale to use for formatting numbers and dates.
* @serial
*/
private Locale locale;
/**
* The string that the formatted values are to be plugged into. In other words, this
* is the pattern supplied on construction with all of the {} expressions taken out.
* @serial
*/
private String pattern = "";
/** The initially expected number of subformats in the format */
private static final int INITIAL_FORMATS = 10;
/**
* An array of formatters, which are used to format the arguments.
* @serial
*/
private Format[] formats = new Format[INITIAL_FORMATS];
/**
* The positions where the results of formatting each argument are to be inserted
* into the pattern.
* @serial
*/
private int[] offsets = new int[INITIAL_FORMATS];
/**
* The argument numbers corresponding to each formatter. (The formatters are stored
* in the order they occur in the pattern, not in the order in which the arguments
* are specified.)
* @serial
*/
private int[] argumentNumbers = new int[INITIAL_FORMATS];
/**
* One less than the number of entries in offsets. Can also be thought of
* as the index of the highest-numbered element in offsets that is being used.
* All of these arrays should have the same number of elements being used as offsets
* does, and so this variable suffices to tell us how many entries are in all of them.
* @serial
*/
private int maxOffset = -1;
/**
* Internal routine used by format. If characterIterators is
* non-null, AttributedCharacterIterator will be created from the
* subformats as necessary. If characterIterators is null
* and fp is non-null and identifies
* Field.MESSAGE_ARGUMENT, the location of
* the first replaced argument will be set in it.
*
* @exception IllegalArgumentException if an argument in the
* arguments array is not of the type
* expected by the format element(s) that use it.
*/
private StringBuffer subformat(Object[] arguments, StringBuffer result,
FieldPosition fp, Listiterator to the StringBuffer result.
*/
private void append(StringBuffer result, CharacterIterator iterator) {
if (iterator.first() != CharacterIterator.DONE) {
char aChar;
result.append(iterator.first());
while ((aChar = iterator.next()) != CharacterIterator.DONE) {
result.append(aChar);
}
}
}
// Indices for segments
private static final int SEG_RAW = 0;
private static final int SEG_INDEX = 1;
private static final int SEG_TYPE = 2;
private static final int SEG_MODIFIER = 3; // modifier or subformat
// Indices for type keywords
private static final int TYPE_NULL = 0;
private static final int TYPE_NUMBER = 1;
private static final int TYPE_DATE = 2;
private static final int TYPE_TIME = 3;
private static final int TYPE_CHOICE = 4;
private static final String[] TYPE_KEYWORDS = {
"",
"number",
"date",
"time",
"choice"
};
// Indices for number modifiers
private static final int MODIFIER_DEFAULT = 0; // common in number and date-time
private static final int MODIFIER_CURRENCY = 1;
private static final int MODIFIER_PERCENT = 2;
private static final int MODIFIER_INTEGER = 3;
private static final String[] NUMBER_MODIFIER_KEYWORDS = {
"",
"currency",
"percent",
"integer"
};
// Indices for date-time modifiers
private static final int MODIFIER_SHORT = 1;
private static final int MODIFIER_MEDIUM = 2;
private static final int MODIFIER_LONG = 3;
private static final int MODIFIER_FULL = 4;
private static final String[] DATE_TIME_MODIFIER_KEYWORDS = {
"",
"short",
"medium",
"long",
"full"
};
// Date-time style values corresponding to the date-time modifiers.
private static final int[] DATE_TIME_MODIFIERS = {
DateFormat.DEFAULT,
DateFormat.SHORT,
DateFormat.MEDIUM,
DateFormat.LONG,
DateFormat.FULL,
};
private void makeFormat(int position, int offsetNumber,
StringBuilder[] textSegments)
{
String[] segments = new String[textSegments.length];
for (int i = 0; i < textSegments.length; i++) {
StringBuilder oneseg = textSegments[i];
segments[i] = (oneseg != null) ? oneseg.toString() : "";
}
// get the argument number
int argumentNumber;
try {
argumentNumber = Integer.parseInt(segments[SEG_INDEX]); // always unlocalized!
} catch (NumberFormatException e) {
throw new IllegalArgumentException("can't parse argument number: "
+ segments[SEG_INDEX], e);
}
if (argumentNumber < 0) {
throw new IllegalArgumentException("negative argument number: "
+ argumentNumber);
}
// resize format information arrays if necessary
if (offsetNumber >= formats.length) {
int newLength = formats.length * 2;
Format[] newFormats = new Format[newLength];
int[] newOffsets = new int[newLength];
int[] newArgumentNumbers = new int[newLength];
System.arraycopy(formats, 0, newFormats, 0, maxOffset + 1);
System.arraycopy(offsets, 0, newOffsets, 0, maxOffset + 1);
System.arraycopy(argumentNumbers, 0, newArgumentNumbers, 0, maxOffset + 1);
formats = newFormats;
offsets = newOffsets;
argumentNumbers = newArgumentNumbers;
}
int oldMaxOffset = maxOffset;
maxOffset = offsetNumber;
offsets[offsetNumber] = segments[SEG_RAW].length();
argumentNumbers[offsetNumber] = argumentNumber;
// now get the format
Format newFormat = null;
if (segments[SEG_TYPE].length() != 0) {
int type = findKeyword(segments[SEG_TYPE], TYPE_KEYWORDS);
switch (type) {
case TYPE_NULL:
// Type "" is allowed. e.g., "{0,}", "{0,,}", and "{0,,#}"
// are treated as "{0}".
break;
case TYPE_NUMBER:
switch (findKeyword(segments[SEG_MODIFIER], NUMBER_MODIFIER_KEYWORDS)) {
case MODIFIER_DEFAULT:
newFormat = NumberFormat.getInstance(locale);
break;
case MODIFIER_CURRENCY:
newFormat = NumberFormat.getCurrencyInstance(locale);
break;
case MODIFIER_PERCENT:
newFormat = NumberFormat.getPercentInstance(locale);
break;
case MODIFIER_INTEGER:
newFormat = NumberFormat.getIntegerInstance(locale);
break;
default: // DecimalFormat pattern
try {
newFormat = new DecimalFormat(segments[SEG_MODIFIER],
DecimalFormatSymbols.getInstance(locale));
} catch (IllegalArgumentException e) {
maxOffset = oldMaxOffset;
throw e;
}
break;
}
break;
case TYPE_DATE:
case TYPE_TIME:
int mod = findKeyword(segments[SEG_MODIFIER], DATE_TIME_MODIFIER_KEYWORDS);
if (mod >= 0 && mod < DATE_TIME_MODIFIER_KEYWORDS.length) {
if (type == TYPE_DATE) {
newFormat = DateFormat.getDateInstance(DATE_TIME_MODIFIERS[mod],
locale);
} else {
newFormat = DateFormat.getTimeInstance(DATE_TIME_MODIFIERS[mod],
locale);
}
} else {
// SimpleDateFormat pattern
try {
newFormat = new SimpleDateFormat(segments[SEG_MODIFIER], locale);
} catch (IllegalArgumentException e) {
maxOffset = oldMaxOffset;
throw e;
}
}
break;
case TYPE_CHOICE:
try {
// ChoiceFormat pattern
newFormat = new ChoiceFormat(segments[SEG_MODIFIER]);
} catch (Exception e) {
maxOffset = oldMaxOffset;
throw new IllegalArgumentException("Choice Pattern incorrect: "
+ segments[SEG_MODIFIER], e);
}
break;
default:
maxOffset = oldMaxOffset;
throw new IllegalArgumentException("unknown format type: " +
segments[SEG_TYPE]);
}
}
formats[offsetNumber] = newFormat;
}
private static final int findKeyword(String s, String[] list) {
for (int i = 0; i < list.length; ++i) {
if (s.equals(list[i]))
return i;
}
// Try trimmed lowercase.
String ls = s.trim().toLowerCase(Locale.ROOT);
if (ls != s) {
for (int i = 0; i < list.length; ++i) {
if (ls.equals(list[i]))
return i;
}
}
return -1;
}
private static final void copyAndFixQuotes(String source, int start, int end,
StringBuilder target) {
boolean quoted = false;
for (int i = start; i < end; ++i) {
char ch = source.charAt(i);
if (ch == '{') {
if (!quoted) {
target.append('\'');
quoted = true;
}
target.append(ch);
} else if (ch == '\'') {
target.append("''");
} else {
if (quoted) {
target.append('\'');
quoted = false;
}
target.append(ch);
}
}
if (quoted) {
target.append('\'');
}
}
/**
* After reading an object from the input stream, do a simple verification
* to maintain class invariants.
* @throws InvalidObjectException if the objects read from the stream is invalid.
*/
private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
in.defaultReadObject();
boolean isValid = maxOffset >= -1
&& formats.length > maxOffset
&& offsets.length > maxOffset
&& argumentNumbers.length > maxOffset;
if (isValid) {
int lastOffset = pattern.length() + 1;
for (int i = maxOffset; i >= 0; --i) {
if ((offsets[i] < 0) || (offsets[i] > lastOffset)) {
isValid = false;
break;
} else {
lastOffset = offsets[i];
}
}
}
if (!isValid) {
throw new InvalidObjectException("Could not reconstruct MessageFormat from corrupt stream.");
}
}
}