All Packages  Class Hierarchy  This Package  Previous  Next  Index

Class jnt.io.Format 

java.lang.Object
   |
   +----jnt.io.Format
public class Format
extends Object
Simulate printf() in Java.

NOTE: the code for this Java class was provided by Cay Horstmann and Gary Cornel from their book, "Core Java" (SunSoft Press) and is included here for non-commercial purposes only. We thank the authors for making this utility available.

Constructor Index

o Format(String)
Formats the number following printf conventions.

Method Index

o atof(String)
Converts a string of digits to an double
o atoi(String)
Converts a string of digits (decimal, octal or hex) to an integer
o atol(String)
Converts a string of digits (decimal, octal or hex) to a long integer
o form(char)
Formats a character into a string (like sprintf in C)
o form(double)
Formats a double into a string (like sprintf in C)
o form(long)
Formats a long integer into a string (like sprintf in C)
o form(String)
Formats a string into a larger string (like sprintf in C)
o main(String[])
a test stub for the format class
o print(PrintStream, String, char)
prints a formatted number following printf conventions
o print(PrintStream, String, double)
prints a formatted number following printf conventions
o print(PrintStream, String, long)
prints a formatted number following printf conventions
o print(PrintStream, String, String)
prints a formatted number following printf conventions

Constructors

o Format 
 public Format(String s)
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

Parameters:
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
Throws: IllegalArgumentException
if bad format

Methods

o print 
 public static void print(PrintStream s,
                          String fmt,
                          double x)
prints a formatted number following printf conventions

Parameters:
s - a PrintStream
fmt - the format string
x - the double to print
o print 
 public static void print(PrintStream s,
                          String fmt,
                          long x)
prints a formatted number following printf conventions

Parameters:
s - a PrintStream
fmt - the format string
x - the long to print
o print 
 public static void print(PrintStream s,
                          String fmt,
                          char x)
prints a formatted number following printf conventions

Parameters:
s - a PrintStream
fmt - the format string
x - the character to
o print 
 public static void print(PrintStream s,
                          String fmt,
                          String x)
prints a formatted number following printf conventions

Parameters:
s - a PrintStream, fmt the format string
x - a string that represents the digits to print
o atoi 
 public static int atoi(String s)
Converts a string of digits (decimal, octal or hex) to an integer

Parameters:
s - a string
Returns:
the numeric value of the prefix of s representing a base 10 integer
o atol 
 public static long atol(String s)
Converts a string of digits (decimal, octal or hex) to a long integer

Parameters:
s - a string
Returns:
the numeric value of the prefix of s representing a base 10 integer
o atof 
 public static double atof(String s)
Converts a string of digits to an double

Parameters:
s - a string
o form 
 public String form(double x)
Formats a double into a string (like sprintf in C)

Parameters:
x - the number to format
Returns:
the formatted string
Throws: IllegalArgumentException
if bad argument
o form 
 public String form(long x)
Formats a long integer into a string (like sprintf in C)

Parameters:
x - the number to format
Returns:
the formatted string
o form 
 public String form(char c)
Formats a character into a string (like sprintf in C)

Parameters:
x - the value to format
Returns:
the formatted string
o form 
 public String form(String s)
Formats a string into a larger string (like sprintf in C)

Parameters:
x - the value to format
Returns:
the formatted string
o main 
 public static void main(String a[])
a test stub for the format class 

All Packages  Class Hierarchy  This Package  Previous  Next  Index