📄 format.java
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/*
* 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
*/
/* CHANGE HISTORY:
*
* DDG changed 'isSpace()' to 'isSpaceChar()' was depricated
* DDG 1/5/00 fixed fixed_format rounding bug
*/
package org.trinet.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
*
*
* a % (required)
*
* a modifier (optional)
*
*
+
forces display of + for positive numbers
*
0
show leading zeroes
*
-
align left in the field
*
space
prepend a space in front of positive numbers
*
#
use "alternate" format. Add 0 or 0x for octal or hexadecimal numbers. Don't suppress trailing zeroes in general floating point format.
*
*
* an integer denoting field width (optional)
*
* a period followed by an integer denoting precision (optional)
*
* a format descriptor (required)
*
*
f
floating point number in fixed format
*
e, E
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.
*
g, G
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.
*
d, i
integer in decimal
*
x
integer in hexadecimal
*
o
integer in octal
*
s
string
*
c
character
*
*
* @exception IllegalArgumentException if bad format
*/
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.isSpaceChar(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.isSpaceChar(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.isSpaceChar(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);
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