Format.java | searchcode

/java/obsolete/gwt2_2/dtai/util/Format.java

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Java | 551 lines | 358 code | 64 blank | 129 comment | 216 complexity | 81fdb736e537f4abc3807cf50bdf4797 MD5 | raw file
Possible License(s): LGPL-2.0

/*

 * Gary Cornell and Cay S. Horstmann, Core Java (Book/CD-ROM)

 * Published By SunSoft Press/Prentice-Hall

 * Copyright (C) 1996 Sun Microsystems Inc.

 * All Rights Reserved. ISBN 0-13-565755-5

 *

 * Permission to use, copy, modify, and distribute this

 * software and its documentation for NON-COMMERCIAL purposes

 * and without fee is hereby granted provided that this

 * copyright notice appears in all copies.

 *

 * THE AUTHORS AND PUBLISHER MAKE NO REPRESENTATIONS OR

 * WARRANTIES ABOUT THE SUITABILITY OF THE SOFTWARE, EITHER

 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A

 * PARTICULAR PURPOSE, OR NON-INFRINGEMENT. THE AUTHORS

 * AND PUBLISHER SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED

 * BY LICENSEE AS A RESULT OF USING, MODIFYING OR DISTRIBUTING

 * THIS SOFTWARE OR ITS DERIVATIVES.

 */



/**

 * A class for formatting numbers that follows printf conventions.

 * Also implements C-like atoi and atof functions

 * @version 1.01 15 Feb 1996

 * @author Cay Horstmann

 */



package dtai.util;



import java.io.*;



public class Format



{ /**

  * Formats the number following printf conventions.

  * Main limitation: Can only handle one format parameter at a time

  * Use multiple Format objects to format more than one number

  * @param s the format string following printf conventions

  * The string has a prefix, a format code and a suffix. The prefix and suffix

  * become part of the formatted output. The format code directs the

  * formatting of the (single) parameter to be formatted. The code has the

  * following structure

  * <ul>

  * <li> a % (required)

  * <li> a modifier (optional)

  * <dl>

  * <dt> + <dd> forces display of + for positive numbers

  * <dt> 0 <dd> show leading zeroes

  * <dt> - <dd> align left in the field

  * <dt> space <dd> prepend a space in front of positive numbers

  * <dt> # <dd> use "alternate" format. Add 0 or 0x for octal or hexadecimal numbers. Don't suppress trailing zeroes in general floating point format.

  * </dl>

  * <li> an integer denoting field width (optional)

  * <li> a period followed by an integer denoting precision (optional)

  * <li> a format descriptor (required)

  * <dl>

  * <dt>f <dd> floating point number in fixed format

  * <dt>e, E <dd> floating point number in exponential notation (scientific format). The E format results in an uppercase E for the exponent (1.14130E+003), the e format in a lowercase e.

  * <dt>g, G <dd> floating point number in general format (fixed format for small numbers, exponential format for large numbers). Trailing zeroes are suppressed. The G format results in an uppercase E for the exponent (if any), the g format in a lowercase e.

  * <dt>d, i <dd> integer in decimal

  * <dt>x <dd> integer in hexadecimal

  * <dt>o <dd> integer in octal

  * <dt>s <dd> string

  * <dt>c <dd> character

  * </dl>

  * </ul>

  * @exception IllegalArgumentException if bad format

  */



   /**

    * Format constructor

    * @param s  a string

    */

   public Format(String s)

   {  width = 0;

      precision = -1;

      pre = "";

      post = "";

      leading_zeroes = false;

      show_plus = false;

      alternate = false;

      show_space = false;

      left_align = false;

      fmt = ' ';



      int state = 0;

      int length = s.length();

      int parse_state = 0;

      // 0 = prefix, 1 = flags, 2 = width, 3 = precision,

      // 4 = format, 5 = end

      int i = 0;



      while (parse_state == 0)

      {  if (i >= length) parse_state = 5;

         else if (s.charAt(i) == '%')

         {  if (i < length - 1)

            {  if (s.charAt(i + 1) == '%')

               {  pre = pre + '%';

                  i++;

               }

               else

                  parse_state = 1;

            }

            else throw new java.lang.IllegalArgumentException();

         }

         else

            pre = pre + s.charAt(i);

         i++;

      }

      while (parse_state == 1)

      {  if (i >= length) parse_state = 5;

         else if (s.charAt(i) == ' ') show_space = true;

         else if (s.charAt(i) == '-') left_align = true;

         else if (s.charAt(i) == '+') show_plus = true;

         else if (s.charAt(i) == '0') leading_zeroes = true;

         else if (s.charAt(i) == '#') alternate = true;

         else { parse_state = 2; i--; }

         i++;

      }

      while (parse_state == 2)

      {  if (i >= length) parse_state = 5;

         else if ('0' <= s.charAt(i) && s.charAt(i) <= '9')

         {  width = width * 10 + s.charAt(i) - '0';

            i++;

         }

         else if (s.charAt(i) == '.')

         {  parse_state = 3;

            precision = 0;

            i++;

         }

         else

            parse_state = 4;

      }

      while (parse_state == 3)

      {  if (i >= length) parse_state = 5;

         else if ('0' <= s.charAt(i) && s.charAt(i) <= '9')

         {  precision = precision * 10 + s.charAt(i) - '0';

            i++;

         }

         else

            parse_state = 4;

      }

      if (parse_state == 4)

      {  if (i >= length) parse_state = 5;

         else fmt = s.charAt(i);

         i++;

      }

      if (i < length)

         post = s.substring(i, length);

   }



  /**

  * prints a formatted number following printf conventions

  * @param s a PrintStream

  * @param fmt the format string

  * @param x the double to print

  */



   public static void print(java.io.PrintStream s, String fmt, double x)

   {  s.print(new Format(fmt).form(x));

   }



  /**

  * prints a formatted number following printf conventions

  * @param s a PrintStream

  * @param fmt the format string

  * @param x the long to print

  */

  public static void print(java.io.PrintStream s, String fmt, long x)

   {  s.print(new Format(fmt).form(x));

   }



  /**

  * prints a formatted number following printf conventions

  * @param s a PrintStream

  * @param fmt the format string

  * @param x the character to

  */



   public static void print(java.io.PrintStream s, String fmt, char x)

   {  s.print(new Format(fmt).form(x));

   }



  /**

  * prints a formatted number following printf conventions

  * @param s a PrintStream, fmt the format string

  * @param x a string that represents the digits to print

  */



   public static void print(java.io.PrintStream s, String fmt, String x)

   {  s.print(new Format(fmt).form(x));

   }



  /**

  * Converts a string of digits (decimal, octal or hex) to an integer

  * @param s a string

  * @return the numeric value of the prefix of s representing a base 10 integer

  */



   public static int atoi(String s)

   {  return (int)atol(s);

   }



  /**

  * Converts a string of digits (decimal, octal or hex) to a long integer

  * @param s a string

  * @return the numeric value of the prefix of s representing a base 10 integer

  */



   public static long atol(String s)

   {  int i = 0;



      while (i < s.length() && Character.isSpace(s.charAt(i))) i++;

      if (i < s.length() && s.charAt(i) == '0')

      {  if (i + 1 < s.length() && (s.charAt(i + 1) == 'x' || s.charAt(i + 1) == 'X'))

            return parseLong(s.substring(i + 2), 16);

         else return parseLong(s, 8);

      }

      else return parseLong(s, 10);

   }



   private static long parseLong(String s, int base)

   {  int i = 0;

      int sign = 1;

      long r = 0;



      while (i < s.length() && Character.isSpace(s.charAt(i))) i++;

      if (i < s.length() && s.charAt(i) == '-') { sign = -1; i++; }

      else if (i < s.length() && s.charAt(i) == '+') { i++; }

      while (i < s.length())

      {  char ch = s.charAt(i);

         if ('0' <= ch && ch < '0' + base)

            r = r * base + ch - '0';

         else if ('A' <= ch && ch < 'A' + base - 10)

            r = r * base + ch - 'A' + 10 ;

         else if ('a' <= ch && ch < 'a' + base - 10)

            r = r * base + ch - 'a' + 10 ;

         else

            return r * sign;

         i++;

      }

      return r * sign;

   }



   /**

   * Converts a string of digits to an double

   * @param s a string

   */



   public static double atof(String s)

   {  int i = 0;

      int sign = 1;

      double r = 0; // integer part

      double f = 0; // fractional part

      double p = 1; // exponent of fractional part

      int state = 0; // 0 = int part, 1 = frac part



      while (i < s.length() && Character.isSpace(s.charAt(i))) i++;

      if (i < s.length() && s.charAt(i) == '-') { sign = -1; i++; }

      else if (i < s.length() && s.charAt(i) == '+') { i++; }

      while (i < s.length())

      {  char ch = s.charAt(i);

         if ('0' <= ch && ch <= '9')

         {  if (state == 0)

               r = r * 10 + ch - '0';

            else if (state == 1)

            {  p = p / 10;

               r = r + p * (ch - '0');

            }

         }

         else if (ch == '.')

         {  if (state == 0) state = 1;

            else return sign * r;

         }

         else if (ch == 'e' || ch == 'E')

         {  long e = (int)parseLong(s.substring(i + 1), 10);

            return sign * r * Math.pow(10, e);

         }

         else return sign * r;

         i++;

      }

      return sign * r;

   }



   /**

   * Formats a double into a string (like sprintf in C)

   * @param x the number to format

   * @return the formatted string

   * @exception IllegalArgumentException if bad argument

   */



   public String form(double x)

   {  String r;

      if (precision < 0) precision = 6;

      int s = 1;

      if (x < 0) { x = -x; s = -1; }

      if (fmt == 'f')

         r = fixed_format(x);

      else if (fmt == 'e' || fmt == 'E' || fmt == 'g' || fmt == 'G')

         r = exp_format(x);

      else throw new java.lang.IllegalArgumentException();



      return pad(sign(s, r));

   }



   /**

   * Formats a long integer into a string (like sprintf in C)

   * @param x the number to format

   * @return the formatted string

   */



   public String form(long x)

   {  String r;

      int s = 0;

      if (fmt == 'd' || fmt == 'i')

      {  s = 1;

         if (x < 0) { x = -x; s = -1; }

         r = "" + x;

      }

      else if (fmt == 'o')

         r = convert(x, 3, 7, "01234567");

      else if (fmt == 'x')

         r = convert(x, 4, 15, "0123456789abcdef");

      else if (fmt == 'X')

         r = convert(x, 4, 15, "0123456789ABCDEF");

      else throw new java.lang.IllegalArgumentException();



      return pad(sign(s, r));

   }



   /**

   * Formats a character into a string (like sprintf in C)

   * @param x the value to format

   * @return the formatted string

   */



   public String form(char c)

   {  if (fmt != 'c')

         throw new java.lang.IllegalArgumentException();



      String r = "" + c;

      return pad(r);

   }



   /**

   * Formats a string into a larger string (like sprintf in C)

   * @param x the value to format

   * @return the formatted string

   */



   public String form(String s)

   {  if (fmt != 's')

         throw new java.lang.IllegalArgumentException();

      if (precision >= 0) s = s.substring(0, precision);

      return pad(s);

   }





   /**

   * a test stub for the format class

   */



   public static void main(String[] a)

   {  double x = 1.23456789012;

      double y = 123;

      double z = 1.2345e30;

      double w = 1.02;

      double u = 1.234e-5;

      int d = 0xCAFE;

      Format.print(System.out, "x = |%f|\n", x);

      Format.print(System.out, "u = |%20f|\n", u);

      Format.print(System.out, "x = |% .5f|\n", x);

      Format.print(System.out, "w = |%20.5f|\n", w);

      Format.print(System.out, "x = |%020.5f|\n", x);

      Format.print(System.out, "x = |%+20.5f|\n", x);

      Format.print(System.out, "x = |%+020.5f|\n", x);

      Format.print(System.out, "x = |% 020.5f|\n", x);

      Format.print(System.out, "y = |%#+20.5f|\n", y);

      Format.print(System.out, "y = |%-+20.5f|\n", y);

      Format.print(System.out, "z = |%20.5f|\n", z);



      Format.print(System.out, "x = |%e|\n", x);

      Format.print(System.out, "u = |%20e|\n", u);

      Format.print(System.out, "x = |% .5e|\n", x);

      Format.print(System.out, "w = |%20.5e|\n", w);

      Format.print(System.out, "x = |%020.5e|\n", x);

      Format.print(System.out, "x = |%+20.5e|\n", x);

      Format.print(System.out, "x = |%+020.5e|\n", x);

      Format.print(System.out, "x = |% 020.5e|\n", x);

      Format.print(System.out, "y = |%#+20.5e|\n", y);

      Format.print(System.out, "y = |%-+20.5e|\n", y);



      Format.print(System.out, "x = |%g|\n", x);

      Format.print(System.out, "z = |%g|\n", z);

      Format.print(System.out, "w = |%g|\n", w);

      Format.print(System.out, "u = |%g|\n", u);

      Format.print(System.out, "y = |%.2g|\n", y);

      Format.print(System.out, "y = |%#.2g|\n", y);

      Format.print(System.out, "d = |%d|\n", d);

      Format.print(System.out, "d = |%20d|\n", d);

      Format.print(System.out, "d = |%020d|\n", d);

      Format.print(System.out, "d = |%+20d|\n", d);

      Format.print(System.out, "d = |% 020d|\n", d);

      Format.print(System.out, "d = |%-20d|\n", d);

      Format.print(System.out, "d = |%20.8d|\n", d);

      Format.print(System.out, "d = |%x|\n", d);

      Format.print(System.out, "d = |%20X|\n", d);

      Format.print(System.out, "d = |%#20x|\n", d);

      Format.print(System.out, "d = |%020X|\n", d);

      Format.print(System.out, "d = |%20.8x|\n", d);

      Format.print(System.out, "d = |%o|\n", d);

      Format.print(System.out, "d = |%020o|\n", d);

      Format.print(System.out, "d = |%#20o|\n", d);

      Format.print(System.out, "d = |%#020o|\n", d);

      Format.print(System.out, "d = |%20.12o|\n", d);



      Format.print(System.out, "s = |%-20s|\n", "Hello");

      Format.print(System.out, "s = |%-20c|\n", '!');

   }





   private static String repeat(char c, int n)

   {  if (n <= 0) return "";

      StringBuffer s = new StringBuffer(n);

      for (int i = 0; i < n; i++) s.append(c);

      return s.toString();

   }



   private static String convert(long x, int n, int m, String d)

   {  if (x == 0) return "0";

      String r = "";

      while (x != 0)

      {  r = d.charAt((int)(x & m)) + r;

         x = x >>> n;

      }

      return r;

   }



   private String pad(String r)

   {  String p = repeat(' ', width - r.length());

      if (left_align) return pre + r + p + post;

      else return pre + p + r + post;

   }



   private String sign(int s, String r)

   {  String p = "";

      if (s < 0) p = "-";

      else if (s > 0)

      {  if (show_plus) p = "+";

         else if (show_space) p = " ";

      }

      else

      {  if (fmt == 'o' && alternate && r.length() > 0 && r.charAt(0) != '0') p = "0";

         else if (fmt == 'x' && alternate) p = "0x";

         else if (fmt == 'X' && alternate) p = "0X";

      }

      int w = 0;

      if (leading_zeroes)

         w = width;

      else if ((fmt == 'd' || fmt == 'i' || fmt == 'x' || fmt == 'X' || fmt == 'o')

         && precision > 0) w = precision;



      return p + repeat('0', w - p.length() - r.length()) + r;

   }





   private String fixed_format(double d)

   {  String f = "";



      if (d > 0x7FFFFFFFFFFFFFFFL) return exp_format(d);



      long l = (long)(precision == 0 ? d + 0.5 : d);

      f = f + l;



      double fr = d - l; // fractional part

      if (fr >= 1 || fr < 0) return exp_format(d);



      return f + frac_part(fr);

   }



   private String frac_part(double fr)

   // precondition: 0 <= fr < 1

   {  String z = "";

      if (precision > 0)

      {  double factor = 1;

         String leading_zeroes = "";

         for (int i = 1; i <= precision && factor <= 0x7FFFFFFFFFFFFFFFL; i++)

         {  factor *= 10;

            leading_zeroes = leading_zeroes + "0";

         }

         long l = (long) (factor * fr + 0.5);



         z = leading_zeroes + l;

         z = z.substring(z.length() - precision, z.length());

      }





      if (precision > 0 || alternate) z = "." + z;

      if ((fmt == 'G' || fmt == 'g') && !alternate)

      // remove trailing zeroes and decimal point

      {  int t = z.length() - 1;

         while (t >= 0 && z.charAt(t) == '0') t--;

         if (t >= 0 && z.charAt(t) == '.') t--;

         z = z.substring(0, t + 1);

      }

      return z;

   }



   private String exp_format(double d)

   {  String f = "";

      int e = 0;

      double dd = d;

      double factor = 1;

      while (dd > 10) { e++; factor /= 10; dd = dd / 10; }

      while (dd < 1) { e--; factor *= 10; dd = dd * 10; }

      if ((fmt == 'g' || fmt == 'G') && e >= -4 && e < precision)

         return fixed_format(d);



      d = d * factor;

      f = f + fixed_format(d);



      if (fmt == 'e' || fmt == 'g')

         f = f + "e";

      else

         f = f + "E";



      String p = "000";

      if (e >= 0)

      {  f = f + "+";

         p = p + e;

      }

      else

      {  f = f + "-";

         p = p + (-e);

      }



      return f + p.substring(p.length() - 3, p.length());

   }



   private int width;

   private int precision;

   private String pre;

   private String post;

   private boolean leading_zeroes;

   private boolean show_plus;

   private boolean alternate;

   private boolean show_space;

   private boolean left_align;

   private char fmt; // one of cdeEfgGiosxXos

}