decimalformat.java

gcc的组建

		pos.setErrorIndex(index);
		return null;
	      }
	    buf = frac_buf = new StringBuffer();
	    frac_buf.append('.');
	    int_part = false;
	  }
	else if (c == symbols.getExponential())
	  {
	    buf = exp_buf = new StringBuffer();
	    int_part = false;
	    exp_part = true;
	    exp_index = index+1;
	  }
	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;
      }
    else if (! got_pos_suf)
      {
       pos.setErrorIndex(index);
       return null;
      }

    String suffix = is_neg ? ns : positiveSuffix;
    long parsedMultiplier = 1;
    boolean use_long;

    if (is_neg)
      int_buf.insert(0, '-');

    // Now handle the exponential part if there is one.
    if (exp_buf != null)
      {
	int exponent_value;

	try
	  {
	    exponent_value = Integer.parseInt(exp_buf.toString());
	  }
	catch (NumberFormatException x1)
	  {
	    pos.setErrorIndex(exp_index);
	    return null;
	  }

	if (frac_buf == null)
	  {
	    // We only have to add some zeros to the int part.
	    // Build a multiplier.
	    for (int i = 0; i < exponent_value; i++)
	      int_buf.append('0');
	    
	    use_long = true;
	  }
	else
	  {
	    boolean long_sufficient;

	    if (exponent_value < frac_buf.length()-1)
	      {
		int lastNonNull = -1;
		/* We have to check the fraction buffer: it may only be full of '0'
		 * or be sufficiently filled with it to convert the number into Long.
		 */
		for (int i = 1; i < frac_buf.length(); i++)
		  if (frac_buf.charAt(i) != '0')
		    lastNonNull = i;

		long_sufficient = (lastNonNull < 0 || lastNonNull <= exponent_value);
	      }
	    else
	      long_sufficient = true;
	    
	    if (long_sufficient)
	      {
		for (int i = 1; i < frac_buf.length() && i < exponent_value; i++)
		  int_buf.append(frac_buf.charAt(i));
		for (int i = frac_buf.length()-1; i < exponent_value; i++)
		  int_buf.append('0');
		use_long = true;
	      }
	    else
	      {
		/*
		 * A long type is not sufficient, we build the full buffer to
		 * be parsed by Double.
		 */
		int_buf.append(frac_buf);
		int_buf.append('E');
		int_buf.append(exp_buf);
		use_long = false;
	      }
	  }
      }
    else
      {
	if (frac_buf != null)
	  {
	    /* Check whether the fraction buffer contains only '0' */
	    int i;
	    for (i = 1; i < frac_buf.length(); i++)
	      if (frac_buf.charAt(i) != '0')
		break;
	   
	    if (i != frac_buf.length())
	      {
		use_long = false;
		int_buf.append(frac_buf);
	      }
	    else
	      use_long = true;
	  }
	else
	  use_long = true;
      }

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

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

    return result;
  }

  /**
   * Sets the <code>Currency</code> on the
   * <code>DecimalFormatSymbols</code> used, which also sets the
   * currency symbols on those symbols.
   */
  public void setCurrency(Currency currency)
  {
    symbols.setCurrency(currency);
  }

  /**
   * Sets the symbols used by this instance.  This method makes a copy of 
   * the supplied symbols.
   * 
   * @param newSymbols  the symbols (<code>null</code> not permitted).
   */
  public void setDecimalFormatSymbols(DecimalFormatSymbols newSymbols)
  {
    symbols = (DecimalFormatSymbols) newSymbols.clone();
  }

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

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

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

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

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

  public void setMinimumIntegerDigits (int newValue)
  {
    super.setMinimumIntegerDigits(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 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 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: groupingSize);
    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);
  }

  private static final int MAXIMUM_INTEGER_DIGITS = 309; 

  // These names are fixed by the serialization spec.
  private boolean decimalSeparatorAlwaysShown;
  private byte groupingSize;
  private byte minExponentDigits;
  private int exponentRound;
  private int multiplier;
  private String negativePrefix;
  private String negativeSuffix;
  private String positivePrefix;
  private String positiveSuffix;
  private int[] negativePrefixRanges, positivePrefixRanges;
  private HashMap[] negativePrefixAttrs, positivePrefixAttrs;
  private int[] negativeSuffixRanges, positiveSuffixRanges;
  private HashMap[] negativeSuffixAttrs, positiveSuffixAttrs;
  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);

  /**
   * <p>
   * Substitutes the currency symbol into the given string,
   * based on the value used.  Currency symbols can either
   * be a simple series of characters (e.g. '$'), which are
   * simply used as is, or they can be of a more complex
   * form:
   * </p>
   * <p>
   * (lower bound)|(mid value)|(upper bound)
   * </p>
   * <p>
   * where each bound has the syntax '(value)(# or <)(symbol)',
   * to indicate the bounding value and the symbol used.
   * </p>
   * <p>
   * The currency symbol replaces the currency specifier, '\u00a4',
   * an unlocalised character, which thus is used as such in all formats.
   * If this symbol occurs twice, the international currency code is used
   * instead.
   * </p>
   *
   * @param string The string containing the currency specifier, '\u00a4'.
   * @param number the number being formatted.
   * @return a string formatted for the correct currency.
   */
  private String substituteCurrency(String string, double number)
  {
    int index;
    int length;
    char currentChar;
    StringBuffer buf;
    
    index = 0;
    length = string.length();
    buf = new StringBuffer();
    
    while (index < length)
      {
	currentChar = string.charAt(index);
	if (string.charAt(index) == '\u00a4')
	  {
	    if ((index + 1) < length && string.charAt(index + 1) == '\u00a4')
	      {
		buf.append(symbols.getInternationalCurrencySymbol());
		index += 2;
	      }
	    else
	      {
		String symbol;
		
		symbol = symbols.getCurrencySymbol();
		if (symbol.startsWith("="))
		  {
		    String[] bounds;
		    int[] boundValues;
		    String[] boundSymbols;
		    
		    bounds = symbol.substring(1).split("\\|");
		    boundValues = new int[3];
		    boundSymbols = new String[3];
		    for (int a = 0; a < 3; ++a)
		      {
			String[] bound;
			
			bound = bounds[a].split("[#<]");
			boundValues[a] = Integer.parseInt(bound[0]);
			boundSymbols[a] = bound[1];
		      }
		    if (number <= boundValues[0])
		      {
			buf.append(boundSymbols[0]);
		      }
		    else if (number >= boundValues[2])
		      {
			buf.append(boundSymbols[2]);
		      }
		    else 
		      {
			buf.append(boundSymbols[1]);
		      }
		    ++index;
		  }
		else
		  {
		    buf.append(symbol);
		    ++index;
		  }
	      }
	  }
	else
	  {
	    buf.append(string.charAt(index));
	    ++index;
	  }
      }
    return buf.toString();
  }
  
}