decimalformat.java

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	// Strip extraneous trailing `0's.  We can't always detect
	// these in the loop.
	int extra_zeros = Math.min (consecutive_zeros,
				    total_digits - minimumFractionDigits);
	if (extra_zeros > 0)
	  {
	    dest.setLength(dest.length() - extra_zeros);
	    total_digits -= extra_zeros;
	  }

	// If required, add the decimal symbol.
	if (decimalSeparatorAlwaysShown
	    || total_digits > 0)
	  {
	    dest.insert(decimal_index, symbols.getDecimalSeparator());
	    if (fieldPos != null && fieldPos.getField() == FRACTION_FIELD)
	      {
		fieldPos.setBeginIndex(decimal_index + 1);
		fieldPos.setEndIndex(dest.length());
	      }
	  }

	// Finally, print the exponent.
	if (useExponentialNotation)
	  {
	    dest.append(symbols.getExponential());
	    if (exponent < 0)
	      {
		dest.append (symbols.getMinusSign ());
		exponent = - exponent;
	      }
	    index = dest.length();
	    for (count = 0;
		 exponent > 0 || count < minExponentDigits;
		 ++count)
	      {
		long dig = exponent % 10;
		exponent /= 10;
		dest.insert(index, (char) (symbols.getZeroDigit() + dig));
	      }
	  }
      }

    if (fieldPos != null && fieldPos.getField() == INTEGER_FIELD)
      {
	fieldPos.setBeginIndex(integerBeginIndex);
	fieldPos.setEndIndex(integerEndIndex);
      }

    dest.append((is_neg && negativeSuffix != null)
		? negativeSuffix
		: positiveSuffix);
    return dest;
  }

  public StringBuffer format (long number, StringBuffer dest,
			      FieldPosition fieldPos)
  {
    // If using exponential notation, we just format as a double.
    if (useExponentialNotation)
      return format ((double) number, dest, fieldPos);

    boolean is_neg = number < 0;
    if (is_neg)
      {
	if (negativePrefix != null)
	  dest.append(negativePrefix);
	else
	  {
	    dest.append(symbols.getMinusSign());
	    dest.append(positivePrefix);
	  }
	number = - number;
      }
    else
      dest.append(positivePrefix);

    int integerBeginIndex = dest.length();
    int index = dest.length();
    int count = 0;
    while (count < maximumIntegerDigits
	   && (number > 0 || count < minimumIntegerDigits))
      {
	long dig = number % 10;
	number /= 10;
	// NUMBER and DIG will be less than 0 if the original number
	// was the most negative long.
	if (dig < 0)
	  {
	    dig = - dig;
	    number = - number;
	  }

	// Append group separator if required.
	if (groupingUsed && count > 0 && count % groupingSize == 0)
	  dest.insert(index, symbols.getGroupingSeparator());

	dest.insert(index, (char) (symbols.getZeroDigit() + dig));

	++count;
      }

    if (fieldPos != null && fieldPos.getField() == INTEGER_FIELD)
      {
	fieldPos.setBeginIndex(integerBeginIndex);
	fieldPos.setEndIndex(dest.length());
      }

    if (decimalSeparatorAlwaysShown || minimumFractionDigits > 0)
      {
	dest.append(symbols.getDecimalSeparator());
	if (fieldPos != null && fieldPos.getField() == FRACTION_FIELD)
	  {
	    fieldPos.setBeginIndex(dest.length());
	    fieldPos.setEndIndex(dest.length() + minimumFractionDigits);
	  }
      }

    for (count = 0; count < minimumFractionDigits; ++count)
      dest.append(symbols.getZeroDigit());

    dest.append((is_neg && negativeSuffix != null)
		? negativeSuffix
		: positiveSuffix);
    return dest;
  }

  public DecimalFormatSymbols getDecimalFormatSymbols ()
  {
    return symbols;
  }

  public int getGroupingSize ()
  {
    return groupingSize;
  }

  public int getMultiplier ()
  {
    return multiplier;
  }

  public String getNegativePrefix ()
  {
    return negativePrefix;
  }

  public String getNegativeSuffix ()
  {
    return negativeSuffix;
  }

  public String getPositivePrefix ()
  {
    return positivePrefix;
  }

  public String getPositiveSuffix ()
  {
    return positiveSuffix;
  }

  public int hashCode ()
  {
    int hash = (negativeSuffix.hashCode() ^ negativePrefix.hashCode()
		^positivePrefix.hashCode() ^ positiveSuffix.hashCode());
    // FIXME.
    return hash;
  }

  public boolean isDecimalSeparatorAlwaysShown ()
  {
    return decimalSeparatorAlwaysShown;
  }

  public Number parse (String str, ParsePosition pos)
  {
    // Our strategy is simple: copy the text into a buffer,
    // translating or omitting locale-specific information.  Then
    // let Double or Long convert the number for us.

    boolean is_neg = false;
    int index = pos.getIndex();
    StringBuffer buf = new StringBuffer ();

      // We have to check both prefixes, because one might be empty.
      // We want to pick the longest prefix that matches.
    boolean got_pos = str.startsWith(positivePrefix, index);
    String np = (negativePrefix != null
		 ? negativePrefix
		 : positivePrefix + symbols.getMinusSign());
    boolean got_neg = str.startsWith(np, index);

    if (got_pos && got_neg)
      {
	// By checking this way, we preserve ambiguity in the case
	// where the negative format differs only in suffix.  We
	// check this again later.
	if (np.length() > positivePrefix.length())
	  {
	    is_neg = true;
	    index += np.length();
	  }
	else
	  index += positivePrefix.length();
      }
    else if (got_neg)
      {
	is_neg = true;
	index += np.length();
      }
    else if (got_pos)
      index += positivePrefix.length();
    else
      {
	pos.setErrorIndex (index);
	return null;
      }

    // FIXME: handle Inf and NaN.

      // FIXME: do we have to respect minimum/maxmimum digit stuff?
      // What about leading zeros?  What about multiplier?

    int start_index = index;
    int max = str.length();
    char zero = symbols.getZeroDigit();
    int last_group = -1;
    boolean int_part = true;
    boolean exp_part = false;
    for (; index < max; ++index)
      {
	char c = str.charAt(index);

	// FIXME: what about grouping size?
	if (groupingUsed && c == symbols.getGroupingSeparator())
	  {
	    if (last_group != -1
		&& (index - last_group) % groupingSize != 0)
	      {
		pos.setErrorIndex(index);
		return null;
	      }
	    last_group = index;
	  }
	else if (c >= zero && c <= zero + 9)
	  {
	    buf.append((char) (c - zero + '0'));
	    exp_part = false;
	  }
	else if (parseIntegerOnly)
	  break;
	else if (c == symbols.getDecimalSeparator())
	  {
	    if (last_group != -1
		&& (index - last_group) % groupingSize != 0)
	      {
		pos.setErrorIndex(index);
		return null;
	      }
	    buf.append('.');
	    int_part = false;
	  }
	else if (c == symbols.getExponential())
	  {
	    buf.append('E');
	    int_part = false;
	    exp_part = true;
	  }
	else if (exp_part
		 && (c == '+' || c == '-' || c == symbols.getMinusSign()))
	  {
	    // For exponential notation.
	    buf.append(c);
	  }
	else
	  break;
      }

    if (index == start_index)
      {
	// Didn't see any digits.
	pos.setErrorIndex(index);
	return null;
      }

    // Check the suffix.  We must do this before converting the
    // buffer to a number to handle the case of a number which is
    // the most negative Long.
    boolean got_pos_suf = str.startsWith(positiveSuffix, index);
    String ns = (negativePrefix == null ? positiveSuffix : negativeSuffix);
    boolean got_neg_suf = str.startsWith(ns, index);
    if (is_neg)
      {
	if (! got_neg_suf)
	  {
	    pos.setErrorIndex(index);
	    return null;
	  }
      }
    else if (got_pos && got_neg && got_neg_suf)
      {
	is_neg = true;
      }
    else if (got_pos != got_pos_suf && got_neg != got_neg_suf)
      {
	pos.setErrorIndex(index);
	return null;
      }

    String suffix = is_neg ? ns : positiveSuffix;
    if (is_neg)
      buf.insert(0, '-');

    String t = buf.toString();
    Number result = null;
    try
      {
	result = new Long (t);
      }
    catch (NumberFormatException x1)
      {
	try
	  {
	    result = new Double (t);
	  }
	catch (NumberFormatException x2)
	  {
	  }
      }
    if (result == null)
      {
	pos.setErrorIndex(index);
	return null;
      }

    pos.setIndex(index + suffix.length());

    return result;
  }

  public void setDecimalFormatSymbols (DecimalFormatSymbols newSymbols)
  {
    symbols = newSymbols;
  }

  public void setDecimalSeparatorAlwaysShown (boolean newValue)
  {
    decimalSeparatorAlwaysShown = newValue;
  }

  public void setGroupingSize (int groupSize)
  {
    groupingSize = (byte) groupSize;
  }

  public void setMaximumFractionDigits (int newValue)
  {
    maximumFractionDigits = Math.min(newValue, 340);
  }

  public void setMaximumIntegerDigits (int newValue)
  {
    maximumIntegerDigits = Math.min(newValue, 309);
  }

  public void setMinimumFractionDigits (int newValue)
  {
    minimumFractionDigits = Math.min(newValue, 340);
  }

  public void setMinimumIntegerDigits (int newValue)
  {
    minimumIntegerDigits = Math.min(newValue, 309);
  }

  public void setMultiplier (int newValue)
  {
    multiplier = newValue;
  }

  public void setNegativePrefix (String newValue)
  {
    negativePrefix = newValue;
  }

  public void setNegativeSuffix (String newValue)
  {
    negativeSuffix = newValue;
  }

  public void setPositivePrefix (String newValue)
  {
    positivePrefix = newValue;
  }

  public void setPositiveSuffix (String newValue)
  {
    positiveSuffix = newValue;
  }

  private final void quoteFix (StringBuffer buf, String text, String patChars)
  {
    int len = text.length();
    for (int index = 0; index < len; ++index)
      {
	char c = text.charAt(index);
	if (patChars.indexOf(c) != -1)
	  {
	    buf.append('\'');
	    buf.append(c);
	    buf.append('\'');
	  }
	else
	  buf.append(c);
      }
  }

  private final String computePattern (DecimalFormatSymbols syms)
  {
    StringBuffer mainPattern = new StringBuffer ();
    // We have to at least emit a zero for the minimum number of
    // digits.  Past that we need hash marks up to the grouping
    // separator (and one beyond).
    int total_digits = Math.max(minimumIntegerDigits,
				groupingUsed ? groupingSize + 1: 0);
    for (int i = 0; i < total_digits - minimumIntegerDigits; ++i)
      mainPattern.append(syms.getDigit());
    for (int i = total_digits - minimumIntegerDigits; i < total_digits; ++i)
      mainPattern.append(syms.getZeroDigit());
    // Inserting the gropuing operator afterwards is easier.
    if (groupingUsed)
      mainPattern.insert(mainPattern.length() - groupingSize,
			 syms.getGroupingSeparator());
    // See if we need decimal info.
    if (minimumFractionDigits > 0 || maximumFractionDigits > 0
	|| decimalSeparatorAlwaysShown)
      mainPattern.append(syms.getDecimalSeparator());
    for (int i = 0; i < minimumFractionDigits; ++i)
      mainPattern.append(syms.getZeroDigit());
    for (int i = minimumFractionDigits; i < maximumFractionDigits; ++i)
      mainPattern.append(syms.getDigit());
    if (useExponentialNotation)
      {
	mainPattern.append(syms.getExponential());
	for (int i = 0; i < minExponentDigits; ++i)
	  mainPattern.append(syms.getZeroDigit());
	if (minExponentDigits == 0)
	  mainPattern.append(syms.getDigit());
      }

    String main = mainPattern.toString();
    String patChars = patternChars (syms);
    mainPattern.setLength(0);

    quoteFix (mainPattern, positivePrefix, patChars);
    mainPattern.append(main);
    quoteFix (mainPattern, positiveSuffix, patChars);

    if (negativePrefix != null)
      {
	quoteFix (mainPattern, negativePrefix, patChars);
	mainPattern.append(main);
	quoteFix (mainPattern, negativeSuffix, patChars);
      }

    return mainPattern.toString();
  }

  public String toLocalizedPattern ()
  {
    return computePattern (symbols);
  }

  public String toPattern ()
  {
    return computePattern (nonLocalizedSymbols);
  }

  // These names are fixed by the serialization spec.
  private boolean decimalSeparatorAlwaysShown;
  private byte groupingSize;
  private byte minExponentDigits;
  private int multiplier;
  private String negativePrefix;
  private String negativeSuffix;
  private String positivePrefix;
  private String positiveSuffix;
  private int serialVersionOnStream = 1;
  private DecimalFormatSymbols symbols;
  private boolean useExponentialNotation;
  private static final long serialVersionUID = 864413376551465018L;

  private void readObject(ObjectInputStream stream)
    throws IOException, ClassNotFoundException
  {
    stream.defaultReadObject();
    if (serialVersionOnStream < 1)
      {
        useExponentialNotation = false;
	serialVersionOnStream = 1;
      }
  }

  // The locale-independent pattern symbols happen to be the same as
  // the US symbols.
  private static final DecimalFormatSymbols nonLocalizedSymbols
    = new DecimalFormatSymbols (Locale.US);
}