messageformat.java

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  public boolean equals (Object obj)
  {
    if (! (obj instanceof MessageFormat))
      return false;
    MessageFormat mf = (MessageFormat) obj;
    return (pattern.equals(mf.pattern)
	    && locale.equals(mf.locale));
  }

  /**
   * A convinience method to format patterns.
   *
   * @param aPattern The pattern used when formatting.
   * @param arguments The array containing the objects to be formatted.
   */
  public static String format (String pattern, Object arguments[])
  {
    MessageFormat mf = new MessageFormat (pattern);
    StringBuffer sb = new StringBuffer ();
    FieldPosition fp = new FieldPosition (NumberFormat.INTEGER_FIELD);
    return mf.format(arguments, sb, fp).toString();
  }

  /**
   * Returns the pattern with the formatted objects.
   *
   * @param source The array containing the objects to be formatted.
   * @param result The StringBuffer where the text is appened.
   * @param fp A FieldPosition object (it is ignored).
   */
  public final StringBuffer format (Object arguments[], StringBuffer appendBuf,
				    FieldPosition ignore)
  {
    appendBuf.append(leader);

    for (int i = 0; i < elements.length; ++i)
      {
	if (elements[i].argNumber >= arguments.length)
	  throw new IllegalArgumentException ();
	Object thisArg = arguments[elements[i].argNumber];

	Format formatter = null;
	if (elements[i].setFormat != null)
	  formatter = elements[i].setFormat;
	else if (elements[i].format != null)
	  {
	    if (elements[i].formatClass != null
		&& ! elements[i].formatClass.isInstance(thisArg))
	      throw new IllegalArgumentException ();
	    formatter = elements[i].format;
	  }
	else if (thisArg instanceof Number)
	  formatter = NumberFormat.getInstance(locale);
	else if (thisArg instanceof Date)
	  formatter = DateFormat.getTimeInstance(DateFormat.DEFAULT, locale);
	else
	  appendBuf.append(thisArg);

	if (formatter != null)
	  {
	    // Special-case ChoiceFormat.
	    if (formatter instanceof ChoiceFormat)
	      {
		StringBuffer buf = new StringBuffer ();
		formatter.format(thisArg, buf, ignore);
		MessageFormat mf = new MessageFormat ();
		mf.setLocale(locale);
		mf.applyPattern(buf.toString());
		mf.format(arguments, appendBuf, ignore);
	      }
	    else
	      formatter.format(thisArg, appendBuf, ignore);
	  }

	appendBuf.append(elements[i].trailer);
      }

    return appendBuf;
  }

  /**
   * Returns the pattern with the formatted objects.
   *
   * @param source The object to be formatted.
   * @param result The StringBuffer where the text is appened.
   * @param fp A FieldPosition object (it is ignored).
   */
  public final StringBuffer format (Object singleArg, StringBuffer appendBuf,
				    FieldPosition ignore)
  {
    Object[] args;

    if (singleArg instanceof Object[])
      {
	// This isn't specified in any manual, but it follows the
	// JDK implementation.
	args = (Object[]) singleArg;
      }
    else
      {
	args = new Object[1];
	args[0] = singleArg;
      }
    return format (args, appendBuf, ignore);
  }

  /**
   * Returns an array with the Formats for
   * the arguments.
   */
  public Format[] getFormats ()
  {
    Format[] f = new Format[elements.length];
    for (int i = elements.length - 1; i >= 0; --i)
      f[i] = elements[i].setFormat;
    return f;
  }

  /**
   * Returns the locale.
   */
  public Locale getLocale ()
  {
    return locale;
  }

  /**
   * Overrides Format.hashCode()
   */
  public int hashCode ()
  {
    // FIXME: not a very good hash.
    return pattern.hashCode() + locale.hashCode();
  }

  private MessageFormat ()
  {
  }

  /**
   * Creates a new MessageFormat object with
   * the specified pattern
   *
   * @param aPattern The Pattern
   */
  public MessageFormat (String pattern)
  {
    locale = Locale.getDefault();
    applyPattern (pattern);
  }

  public Object[] parse (String sourceStr, ParsePosition pos)
  {
    // Check initial text.
    int index = pos.getIndex();
    if (! sourceStr.startsWith(leader, index))
      {
	pos.setErrorIndex(index);
	return null;
      }
    index += leader.length();

    Vector results = new Vector (elements.length, 1);
    // Now check each format.
    for (int i = 0; i < elements.length; ++i)
      {
	Format formatter = null;
	if (elements[i].setFormat != null)
	  formatter = elements[i].setFormat;
	else if (elements[i].format != null)
	  formatter = elements[i].format;

	Object value = null;
	if (formatter instanceof ChoiceFormat)
	  {
	    // We must special-case a ChoiceFormat because it might
	    // have recursive formatting.
	    ChoiceFormat cf = (ChoiceFormat) formatter;
	    String[] formats = (String[]) cf.getFormats();
	    double[] limits = (double[]) cf.getLimits();
	    MessageFormat subfmt = new MessageFormat ();
	    subfmt.setLocale(locale);
	    ParsePosition subpos = new ParsePosition (index);

	    int j;
	    for (j = 0; value == null && j < limits.length; ++j)
	      {
		subfmt.applyPattern(formats[j]);
		subpos.setIndex(index);
		value = subfmt.parse(sourceStr, subpos);
	      }
	    if (value != null)
	      {
		index = subpos.getIndex();
		value = new Double (limits[j]);
	      }
	  }
	else if (formatter != null)
	  {
	    pos.setIndex(index);
	    value = formatter.parseObject(sourceStr, pos);
	    if (value != null)
	      index = pos.getIndex();
	  }
	else
	  {
	    // We have a String format.  This can lose in a number
	    // of ways, but we give it a shot.
	    int next_index = sourceStr.indexOf(elements[i].trailer, index);
	    if (next_index == -1)
	      {
		pos.setErrorIndex(index);
		return null;
	      }
	    value = sourceStr.substring(index, next_index);
	    index = next_index;
	  }

	if (value == null
	    || ! sourceStr.startsWith(elements[i].trailer, index))
	  {
	    pos.setErrorIndex(index);
	    return null;
	  }

	if (elements[i].argNumber >= results.size())
	  results.setSize(elements[i].argNumber + 1);
	results.setElementAt(value, elements[i].argNumber);

	index += elements[i].trailer.length();
      }

    Object[] r = new Object[results.size()];
    results.copyInto(r);
    return r;
  }

  public Object[] parse (String sourceStr) throws ParseException
  {
    ParsePosition pp = new ParsePosition (0);
    Object[] r = parse (sourceStr, pp);
    if (r == null)
      throw new ParseException ("couldn't parse string", pp.getErrorIndex());
    return r;
  }

  public Object parseObject (String sourceStr, ParsePosition pos)
  {
    return parse (sourceStr, pos);
  }

  /**
   * Sets the format for the argument at an specified
   * index.
   *
   * @param index The index.
   * @format The Format object.
   */
  public void setFormat (int variableNum, Format newFormat)
  {
    elements[variableNum].setFormat = newFormat;
  }

  /**
   * Sets the formats for the arguments.
   *
   * @param formats An array of Format objects.
   */
  public void setFormats (Format[] newFormats)
  {
    if (newFormats.length < elements.length)
      throw new IllegalArgumentException ();
    int len = Math.min(newFormats.length, elements.length);
    for (int i = 0; i < len; ++i)
      elements[i].setFormat = newFormats[i];
  }

  /**
   * Sets the locale.
   *
   * @param locale A Locale
   */
  public void setLocale (Locale loc)
  {
    locale = loc;
    if (elements != null)
      {
	for (int i = 0; i < elements.length; ++i)
	  elements[i].setLocale(loc);
      }
  }

  /**
   * Returns the pattern.
   */
  public String toPattern ()
  {
    return pattern;
  }

  // The pattern string.
  private String pattern;
  // The locale.
  private Locale locale;
  // Variables.
  private MessageFormatElement[] elements;
  // Leader text.
  private String leader;
}