sprintf.java

来自「RESIN 3.2 最新源码」· Java 代码 · 共 807 行 · 第 1/2 页

      formatFixed(cb, digits, expt, prec, flags);
    }
    else if (type == 'e' || type == 'E') {
      if (roundDigits(digits, prec + 1))
        expt++;

      formatExpt(cb, digits, expt, prec, flags);
    }
    else {
      if (roundDigits(digits, prec))
        expt++;

      if (expt < -3 || expt > prec)
        formatExpt(cb, digits, expt, prec - 1, flags|NO_TRAIL_ZERO);
      else
        formatFixed(cb, digits, expt, prec - expt, flags|NO_TRAIL_ZERO);
    }
  }

  public static void formatDouble(CharBuffer cb, double value,
                                  int width, int prec, int flags,
                                  int type)
  {
    if (prec < 0)
      prec = 6;

    int offset = cb.length();

    if ((flags & ZERO_FILL) != 0 &&
        (value < 0 || (flags & (POS_PLUS|POS_SPACE)) != 0)) {
        offset++;
        width--;
    }

    if (value < 0) {
      cb.append((char) '-');
      value = -value;
    } else if ((flags & POS_PLUS) != 0) {
      cb.append((char) '+');
    } else if ((flags & POS_SPACE) != 0) {
      cb.append((char) ' ');
    }

    formatDouble(cb, value, prec, flags, type);

    width -= cb.length() - offset;

    for (int i = 0; i < width; i++) {
      if ((flags & LALIGN) != 0)
        cb.append(' ');
      else
        cb.insert(offset, (flags & ZERO_FILL) == 0 ? ' ' : '0');
    }
  }

  private static boolean roundDigits(CharBuffer digits, int len)
  {
    if (len < 0 || digits.length() <= len)
      return false;

    int value = digits.charAt(len);
    if (value < '5')
      return false;

    for (int i = len - 1; i >= 0; i--) {
      int ch = digits.charAt(i);

      if (ch != '9') {
        digits.setCharAt(i, (char) (ch + 1));
        return false;
      }
      digits.setCharAt(i, '0');
    }

    digits.insert(0, '1');

    return true;
  }

  private static void formatFixed(CharBuffer cb, CharBuffer digits,
                                  int expt, int prec, int flags)
  {
    int i = 0;
    int origExpt = expt;

    for (; expt > 0; expt--) {
      if (i < digits.length())
        cb.append((char) digits.charAt(i++));
      else
        cb.append('0');
    }

    if (origExpt <= 0) // || digits.length() == 0)
      cb.append('0');

    if (prec > 0 || (flags & ALT) != 0)
      cb.append('.');

    for (; expt < 0 && prec > 0; expt++) {
      cb.append('0');
      prec--;
    }

    for (; prec > 0 && i < digits.length(); i++) {
      cb.append(digits.charAt(i));
      prec--;
    }

    for (; prec > 0 && (flags & (NO_TRAIL_ZERO|ALT)) != NO_TRAIL_ZERO; prec--)
      cb.append('0');
  }

  private static void formatExpt(CharBuffer cb, CharBuffer digits,
                                 int expt, int prec, int flags)
  {
    if (digits.length() == 0)
      cb.append('0');
    else
      cb.append((char) digits.charAt(0));

    if (prec > 0 || (flags & ALT) != 0)
      cb.append('.');

    for (int i = 1; i < digits.length(); i++) {
      if (prec > 0)
        cb.append((char) digits.charAt(i));
      prec--;
    }

    for (; prec > 0 && (flags & (NO_TRAIL_ZERO|ALT)) != NO_TRAIL_ZERO; prec--)
      cb.append('0');

    if ((flags & BIG) != 0)
      cb.append('E');
    else
      cb.append('e');

    formatInteger(cb, expt - 1, 0, 2, POS_PLUS, 10);
  }

  public static void formatInteger(CharBuffer cb, long dvalue,
                                   int width, int prec, int flags, int radix)
  {
    boolean isBig = (flags & BIG) != 0;
    int begin = cb.length();

    long value;
    if (dvalue > 0)
      value = (long) (dvalue + 0.5);
    else
      value = (long) (dvalue - 0.5);

    if (value < 0 && radix == 10) {
      cb.append((char) '-');
      value = -value;
    } else if (value >= 0 && radix == 10 && (flags & POS_PLUS) != 0)
      cb.append((char) '+');
    else if (value >= 0 && radix == 10 && (flags & POS_SPACE) != 0)
      cb.append((char) ' ');
    else if (value < 0)
      value &= 0xffffffffL;
    else if (radix == 8 && (flags & ALT) != 0 && value != 0)
      cb.append('0');
    else if (radix == 16 && (flags & ALT) != 0)
      cb.append((flags & BIG) == 0 ? "0x" : "0X");

    if ((flags & ZERO_FILL) != 0) {
      width -= cb.length() - begin;
      begin = cb.length();
    }

    int offset = cb.length();
    int len = 0;
    while (value != 0) {
      len++;
      cb.insert(offset, (isBig ? bigDigits : digits)[(int) (value % radix)]);
      value /= radix;
    }

    for (int i = 0; i < prec - len; i++)
      cb.insert(offset, '0');
    if (len == 0 && prec == 0)
      cb.insert(offset, '0');

    width -= cb.length() - begin;
    for (; width > 0; width--) {
      if ((flags & LALIGN) != 0)
        cb.append(' ');
      else if ((flags & ZERO_FILL) != 0 && prec < 0)
        cb.insert(begin, '0');
      else
        cb.insert(begin, ' ');
    }

    if (cb.length() == begin)
      cb.append('0');
  }

  public static void formatInteger(CharBuffer cb, double dvalue,
                                   int width, int prec, int flags, int radix)
  {
    long value;
    if (dvalue > 0)
      value = (long) (dvalue + 0.5);
    else
      value = (long) (dvalue - 0.5);

    formatInteger(cb,value,width,prec,flags,radix);
  }

  public static void formatChar(CharBuffer cb, long ch, int width, int flags)
  {
    int offset = cb.length();

    cb.append((char) ch);

    if ((flags & LALIGN) == 0) {
      for (int i = 0; i < width - 1; i++)
        cb.insert(offset, (char) ' ');
    } else {
      for (int i = 0; i < width - 1; i++)
        cb.append((char) ' ');
    }
  }

  public static void formatString(CharBuffer cb, String string,
                                  int prec, int width, int flags)
  {
    int offset = cb.length();

    if (prec < 0)
      prec = Integer.MAX_VALUE;

    if ((flags & CSVESCAPE) != 0) { cb.append('\"'); offset+=1; width -= 1; }

    for (int i = 0; i < string.length() && i < prec; i++) {
      width--;
      char ch = string.charAt(i);
      if ((flags & JAVAESCAPE) != 0) {
        switch (ch) {
          case '\\':
            cb.append("\\\\"); offset+=1; width-=1; continue;
          case '\n':
            cb.append("\\n"); offset+=1; width-=1; continue;
          case '\r':
            cb.append("\\r"); offset+=1; width-=1; continue;
          case '\"':
            cb.append("\\\""); offset+=1; width-=1; continue;
        }
      }
      if ((flags & XMLESCAPE) != 0) {
        switch (ch) {
          case '<':
            cb.append("&lt;"); offset+=3; width-=3; continue;
          case '>':
            cb.append("&gt;"); offset+=3; width-=3; continue;
          case '&':
            cb.append("&amp;"); offset+=4; width-=4; continue;
          case '\'':
            cb.append("&#039;"); offset+=5; width-=5; continue;
          case '"':
            cb.append("&#034;"); offset+=5; width-=5; continue;
        }
      }
      cb.append(ch);
    }

    if ((flags & CSVESCAPE) != 0) { cb.append('\"'); offset+=1; width -= 1; }

    if ((flags & LALIGN) == 0) {
      for (int i = 0; i < width; i++)
        cb.insert(offset, (char) ' ');
    } else {
      for (int i = 0; i < width; i++)
        cb.append((char) ' ');
    }
  }

  private static void fixBits(CharBuffer cb, String format, int s, int i)
  {
    for (; s < i; s++)
      cb.append((char) format.charAt(s));
  }

  /**
   * Converts some unknown value to a double.
   *
   * @param value the value to be converted.
   *
   * @return the double-converted value.
   */
  public static double toDouble(Object value)
  {
    /** copied from com.caucho.el.Expr */

    if (value == null)
      return 0;
    else if (value instanceof Number) {
      double dValue = ((Number) value).doubleValue();

      if (Double.isNaN(dValue))
        return 0;
      else
        return dValue;
    }
    else if (value.equals(""))
      return 0;
    else if (value instanceof String) {
      double dValue = Double.parseDouble((String) value);

      if (Double.isNaN(dValue))
        return 0;
      else
        return dValue;
    }
    else {
      throw new IllegalArgumentException(L.l("can't convert {0} to double.",
                                             value.getClass().getName()));
    }
  }

  /**
   * Converts some unknown value to a long.
   *
   * @param value the value to be converted.
   *
   * @return the long-converted value.
   */
  public static long toLong(Object value)
  {
    /** copied from com.caucho.el.Expr */

    if (value == null)
      return 0;
    else if (value instanceof Number)
      return ((Number) value).longValue();
    else if (value.equals(""))
      return 0;
    else if (value instanceof String) {
      int sign = 1;
      String string = (String) value;
      int length = string.length();
      long intValue = 0;

      int i = 0;
      for (; i < length && Character.isWhitespace(string.charAt(i)); i++) {
      }

      if (length <= i)
        return 0;

      int ch = string.charAt(i);
      if (ch == '-') {
        sign = -1;
        i++;
      }
      else if (ch == '+')
        i++;

      for (; i < length; i++) {
        ch = string.charAt(i);

        if (ch >= '0' && ch <= '9') {
          intValue = 10 * intValue + ch - '0';
        }
        else if (ch == '.') {
          // truncate the decimal
          i = length;
          break;
        } else
          break;
      }

      for (; i < length && Character.isWhitespace(string.charAt(i)); i++) {
      }

      if (i < length)
        throw new IllegalArgumentException(L.l("can't convert '{0}' to long.", string));

      return sign * intValue;

    }
    else {
      throw new IllegalArgumentException(L.l("can't convert {0} to long.",
                                             value.getClass().getName()));
    }
  }

  /**
   * Converts some unknown value to a String.
   *
   * @param value the value to be converted.
   * @param nullValue the value to return if value == null
   *
   * @return the String converted value
   */
  public static String toString(Object value, String nullValue)
  {
    return (value == null) ? nullValue : value.toString();
  }

}