/*
Format - printf style formatting for Java
Copyright (C) 1995...2002 Cay S. Horstmann (http://horstmann.com)
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package corejava;
import java.io.*;
/**
A class for formatting numbers that follows <tt>printf</tt> conventions.
Also implements C-like <tt>atoi</tt> and <tt>atof</tt> functions
@version 1.22 2002-11-16
@author Cay Horstmann
1998-09-14: Fixed a number of bugs.
1.Formatting the most extreme negative number (-9223372036854775808L) printed with 2 leading minus signs.
2.Printing 0 with a %e or %g format did not work.
3.Printing numbers that were closer to 1 than the number of requested decimal places rounded down rather than up, e.g. formatting 1.999 with %.2f printed 1.00. (This one is pretty serious, of course.)
4.Printing with precision 0 (e.g %10.0f) didn't work.
5.Printing a string with a precision that exceeded the string length (e.g. print "Hello" with %20.10s) caused a StringIndexOutOfBounds error.
1998-10-21: Changed method names from print to printf
2000-06-09: Moved to package com.horstmann; no longer part of
Core Java
2000-06-09: Fixed a number of bugs.
1.Printing 100.0 with %e printed 10.0e1, not 1.0e2
2.Printing Inf and NaN didn't work.
2000-06-09: Coding guideline cleanup
2002-11-16: Move to package com.horstmann.format; licensed under LGPL
*/
public class Format
{
/**
Formats the number following <tt>printf</tt> 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
*/
public Format(String s)
{
width = 0;
precision = -1;
pre = "";
post = "";
leadingZeroes = false;
showPlus = false;
alternate = false;
showSpace = false;
leftAlign = false;
fmt = ' ';
int state = 0;
int length = s.length();
int parseState = 0;
// 0 = prefix, 1 = flags, 2 = width, 3 = precision,
// 4 = format, 5 = end
int i = 0;
while (parseState == 0)
{
if (i >= length) parseState = 5;
else if (s.charAt(i) == '%')
{
if (i < length - 1)
{
if (s.charAt(i + 1) == '%')
{
pre = pre + '%';
i++;
}
else
parseState = 1;
}
else throw new java.lang.IllegalArgumentException();
}
else
pre = pre + s.charAt(i);
i++;
}
while (parseState == 1)
{
if (i >= length) parseState = 5;
else if (s.charAt(i) == ' ') showSpace = true;
else if (s.charAt(i) == '-') leftAlign = true;
else if (s.charAt(i) == '+') showPlus = true;
else if (s.charAt(i) == '0') leadingZeroes = true;
else if (s.charAt(i) == '#') alternate = true;
else { parseState = 2; i--; }
i++;
}
while (parseState == 2)
{
if (i >= length) parseState = 5;
else if ('0' <= s.charAt(i) && s.charAt(i) <= '9')
{
width = width * 10 + s.charAt(i) - '0';
i++;
}
else if (s.charAt(i) == '.')
{
parseState = 3;
precision = 0;
i++;
}
else
parseState = 4;
}
while (parseState == 3)
{
if (i >= length) parseState = 5;
else if ('0' <= s.charAt(i) && s.charAt(i) <= '9')
{
precision = precision * 10 + s.charAt(i) - '0';
i++;
}
else
parseState = 4;
}
if (parseState == 4)
{
if (i >= length) parseState = 5;
else fmt = s.charAt(i);
i++;
}
if (i < length)
post = s.substring(i, length);
}
/**
prints a formatted number following printf conventions
@param fmt the format string
@param x the double to print
*/
public static void printf(String fmt, double x)
{
System.out.print(new Format(fmt).format(x));
}
/**
prints a formatted number following printf conventions
@param fmt the format string
@param x the int to print
*/
public static void printf(String fmt, int x)
{
System.out.print(new Format(fmt).format(x));
}
/**
prints a formatted number following printf conventions
@param fmt the format string
@param x the long to print
*/
public static void printf(String fmt, long x)
{
System.out.print(new Format(fmt).format(x));
}
/**
prints a formatted number following printf conventions
@param fmt the format string
@param x the character to print
*/
public static void printf(String fmt, char x)
{
System.out.print(new Format(fmt).format(x));
}
/**
prints a formatted number following printf conventions
@param fmt the format string
@param x a string to print
*/
public static void printf(String fmt, String x)
{
System.out.print(new Format(fmt).format(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.isWhitespace(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.isWhitespace(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 a <tt>double</tt>
@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.isWhitespace(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 <tt>double</tt> into a string (like sprintf in C)
@param x the number to format
@return the formatted string
@exception IllegalArgumentException if bad argument
*/
public String format(double x)
{
String r;
if (precision < 0) precision = 6;
int s = 1;
if (x < 0) { x = -x; s = -1; }
if (Double.isNaN(x)) r = "NaN";
else if (x == Double.POSITIVE_INFINITY) r = "Inf";
else if (fmt == 'f')
r = fixedFormat(x);
else if (fmt == 'e' || fmt == 'E' || fmt == 'g' || fmt == 'G')
r = expFormat(x);
else throw new java.lang.IllegalArgumentException();
return pad(sign(s, r));
}
/**
Formats an integer into a string (like sprintf in C)
@param x the number to format
@return the formatted string
*/
public String format(int x)
{
long lx = x;
if (fmt == 'o' || fmt == 'x' || fmt == 'X')
lx &= 0xFFFFFFFFL;
return format(lx);
}
/**
Formats a long integer into a string (like sprintf in C)
@param x the number to format
@return the formatted string
*/
public String format(long x)
{
String r;
int s = 0;
if (fmt == 'd' || fmt == 'i')
{
if (x < 0)
{
r = ("" + x).substring(1);
s = -1;
}
else
{
r = "" + x;
s = 1;
}
}
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 format(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 format(String s)
{
if (fmt != 's')
throw new java.lang.IllegalArgumentException();
if (precision >= 0 && precision < s.length())
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;
double v = 10.0;
int d = 0xCAFE;
Format.printf("x = |%f|\n", x);
Format.printf("u = |%20f|\n", u);
Format.printf("x = |% .5f|\n", x);
Format.printf("w = |%20.5f|\n", w);
Format.printf("x = |%020.5f|\n", x);
Format.printf("x = |%+20.5f|\n", x);
Format.printf("x = |%+020.5f|\n", x);
Format.printf("x = |% 020.5f|\n", x);
Format.printf("y = |%#+20.5f|\n", y);
Format.printf("y = |%-+20.5f|\n", y);
Format.printf("z = |%20.5f|\n", z);
Format.printf("x = |%e|\n", x);
Format.printf("u = |%20e|\n", u);
Format.printf("x = |% .5e|\n", x);
Format.printf("w = |%20.5e|\n", w);
Format.printf("x = |%020.5e|\n", x);
Format.printf("x = |%+20.5e|\n", x);
Format.printf("x = |%+020.5e|\n", x);
Format.printf("x = |% 020.5e|\n", x);
Format.printf("y = |%#+20.5e|\n", y);
Format.printf("y = |%-+20.5e|\n", y);
Format.printf("v = |%12.5e|\n", v);
Format.printf("x = |%g|\n", x);
Format.printf("z = |%g|\n", z);
Format.printf("w = |%g|\n", w);
Format.printf("u = |%g|\n", u);
Format.printf("y = |%.2g|\n", y);
Format.printf("y = |%#.2g|\n", y);
Format.printf("d = |%d|\n", d);
Format.printf("d = |%20d|\n", d);
Format.printf("d = |%020d|\n", d);
Format.printf("d = |%+20d|\n", d);
Format.printf("d = |% 020d|\n", d);
Format.printf("d = |%-20d|\n", d);
Format.printf("d = |%20.8d|\n", d);
Format.printf("d = |%x|\n", d);
Format.printf("d = |%20X|\n", d);
Format.printf("d = |%#20x|\n", d);
Format.printf("d = |%020X|\n", d);
Format.printf("d = |%20.8x|\n", d);
Format.printf("d = |%o|\n", d);
Format.printf("d = |%020o|\n", d);
Format.printf("d = |%#20o|\n", d);
Format.printf("d = |%#020o|\n", d);
Format.printf("d = |%20.12o|\n", d);
Format.printf("s = |%-20s|\n", "Hello");
Format.printf("s = |%-20c|\n", '!');
// regression test to confirm fix of reported bugs
Format.printf("|%i|\n", Long.MIN_VALUE);
Format.printf("|%6.2e|\n", 0.0);
Format.printf("|%6.2g|\n", 0.0);
Format.printf("|%6.2f|\n", 9.99);
Format.printf("|%6.2f|\n", 9.999);
Format.printf("|%.2f|\n", 1.999);
Format.printf("|%6.0f|\n", 9.999);
Format.printf("|%20.10s|\n", "Hello");
d = -1;
Format.printf("-1 = |%X|\n", d);
Format.printf("100 = |%e|\n", 100.0); // 2000-06-09
Format.printf("1/0 = |%f|\n", 1.0 / 0.0);
Format.printf("-1/0 = |%e|\n", -1.0 / 0.0);
Format.printf("0/0 = |%g|\n", 0.0 / 0.0);
}
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 (leftAlign) 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 (showPlus) p = "+";
else if (showSpace) 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 (leadingZeroes)
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 fixedFormat(double d)
{
boolean removeTrailing
= (fmt == 'G' || fmt == 'g') && !alternate;
// remove trailing zeroes and decimal point
if (d > 0x7FFFFFFFFFFFFFFFL) return expFormat(d);
if (precision == 0)
return (long)(d + 0.5) + (removeTrailing ? "" : ".");
long whole = (long)d;
double fr = d - whole; // fractional part
if (fr >= 1 || fr < 0) return expFormat(d);
double factor = 1;
String leadingZeroes = "";
for (int i = 1; i <= precision && factor <= 0x7FFFFFFFFFFFFFFFL; i++)
{
factor *= 10;
leadingZeroes = leadingZeroes + "0";
}
long l = (long) (factor * fr + 0.5);
if (l >= factor) { l = 0; whole++; } // CSH 10-25-97
String z = leadingZeroes + l;
z = "." + z.substring(z.length() - precision, z.length());
if (removeTrailing)
{
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 whole + z;
}
private String expFormat(double d)
{
String f = "";
int e = 0;
double dd = d;
double factor = 1;
if (d != 0)
{
while (dd >= 10) { e++; factor /= 10; dd = dd / 10; } // 2000-06-09
while (dd < 1) { e--; factor *= 10; dd = dd * 10; }
}
if ((fmt == 'g' || fmt == 'G') && e >= -4 && e < precision)
return fixedFormat(d);
d = d * factor;
f = f + fixedFormat(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 leadingZeroes;
private boolean showPlus;
private boolean alternate;
private boolean showSpace;
private boolean leftAlign;
private char fmt; // one of cdeEfgGiosxXos
}