org.codehaus.plexus.util

Class TypeFormat

java.lang.Object

org.codehaus.plexus.util.TypeFormat

public final class TypeFormat
extends java.lang.Object

This class provides utility methods to parse CharSequence into primitive types and to format primitive types into StringBuffer.

Methods from this utility class do not create temporary objects and are typically faster than standard library methods (e.g parseDouble(java.lang.CharSequence) is up to 15x faster than Double.parseDouble).

For class instances, formatting is typically performed using specialized java.text.Format (Locale sensitive) and/or using conventional methods (class sensitive). For example:

     public class Foo {
         public static Foo valueOf(CharSequence chars) {...} // Parses.
         public StringBuffer appendTo(StringBuffer sb) {...} // Formats.
         public String toString() {
             return appendTo(new StringBuffer()).toString();
         }
     }
 

This class is public domain (not copyrighted).

Version:

4.6, June 22, 2003

Field Summary

Fields

Modifier and Type	Field and Description
private static char[]	DIGITS Holds the characters used to represent numbers.
private static double[]	DOUBLE_POW_10
private static double	DOUBLE_RELATIVE_ERROR
private static float	FLOAT_RELATIVE_ERROR
private static int[]	INT_POW_10
private static java.lang.String[]	LEADING_ZEROS
private static double	LOG_10
private static long[]	LONG_POW_10

Constructor Summary

Constructors

Modifier	Constructor and Description
private	TypeFormat() Default constructor (forbids derivation).

Method Summary

Modifier and Type	Method and Description
static java.lang.StringBuffer	format(boolean b, java.lang.StringBuffer sb) Formats the specified boolean and appends the resulting text to the StringBuffer argument.
private static java.lang.StringBuffer	format(double d, double precision, boolean precisionOnLastDigit, java.lang.StringBuffer sb) Formats the specified double and appends the resulting text to the StringBuffer argument; the number of significative digits is deduced from the specified precision.
static java.lang.StringBuffer	format(double d, double precision, java.lang.StringBuffer sb) Formats the specified double and appends the resulting text to the StringBuffer argument; the number of significative digits is deduced from the specified precision.
static java.lang.StringBuffer	format(double d, int digits, java.lang.StringBuffer sb) Formats the specified double and appends the resulting text to the StringBuffer argument; the number of significand digits is specified as integer argument.
static java.lang.StringBuffer	format(double d, java.lang.StringBuffer sb) Formats the specified double and appends the resulting text to the StringBuffer argument.
static java.lang.StringBuffer	format(float f, float precision, java.lang.StringBuffer sb) Formats the specified float and appends the resulting text to the StringBuffer argument; the number of significative digits is deduced from the specified precision.
static java.lang.StringBuffer	format(float f, java.lang.StringBuffer sb) Formats the specified float and appends the resulting text to the StringBuffer argument.
static java.lang.StringBuffer	format(int i, int radix, java.lang.StringBuffer sb) Formats the specified int in the specified radix and appends the resulting text to the StringBuffer argument.
static java.lang.StringBuffer	format(int i, java.lang.StringBuffer sb) Formats the specified int and appends the resulting text (decimal representation) to the StringBuffer argument.
static java.lang.StringBuffer	format(long l, int radix, java.lang.StringBuffer sb) Formats the specified long in the specified radix and appends the resulting text to the StringBuffer argument.
static java.lang.StringBuffer	format(long l, java.lang.StringBuffer sb) Formats the specified long and appends the resulting text (decimal representation) to the StringBuffer argument.
static java.lang.StringBuffer	format(short s, int radix, java.lang.StringBuffer sb) Formats the specified short in the specified radix and appends the resulting text to the StringBuffer argument.
static java.lang.StringBuffer	format(short s, java.lang.StringBuffer sb) Formats the specified short and appends the resulting text (decimal representation) to the StringBuffer argument.
private static void	format2(int i, int radix, java.lang.StringBuffer sb)
private static void	format2(long l, int radix, java.lang.StringBuffer sb)
static int	indexOf(java.lang.CharSequence pattern, java.lang.CharSequence chars, int fromIndex) Searches for a particular sequence within a character sequence (general purpose parsing function).
private static double	multE(double value, int E) Returns the product of the specified value with 10 raised at the specified power exponent.
static boolean	parseBoolean(java.lang.CharSequence chars) Parses the specified CharSequence as a boolean.
static double	parseDouble(java.lang.CharSequence chars) Parses this CharSequence as a double.
static float	parseFloat(java.lang.CharSequence chars) Parses this CharSequence as a float.
static int	parseInt(java.lang.CharSequence chars) Parses the specified CharSequence as a signed decimal int.
static int	parseInt(java.lang.CharSequence chars, int radix) Parses the specified CharSequence as a signed int in the specified radix.
static long	parseLong(java.lang.CharSequence chars) Parses the specified CharSequence as a signed decimal long.
static long	parseLong(java.lang.CharSequence chars, int radix) Parses the specified CharSequence as a signed long in the specified radix.
static short	parseShort(java.lang.CharSequence chars) Parses the specified CharSequence as a signed decimal short.
static short	parseShort(java.lang.CharSequence chars, int radix) Parses the specified CharSequence as a signed short in the specified radix.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DIGITS

private static final char[] DIGITS

Holds the characters used to represent numbers.

INT_POW_10

private static final int[] INT_POW_10

LONG_POW_10

private static final long[] LONG_POW_10

LOG_10

private static final double LOG_10

FLOAT_RELATIVE_ERROR

private static final float FLOAT_RELATIVE_ERROR

DOUBLE_RELATIVE_ERROR

private static final double DOUBLE_RELATIVE_ERROR

LEADING_ZEROS

private static java.lang.String[] LEADING_ZEROS

DOUBLE_POW_10

private static final double[] DOUBLE_POW_10

Constructor Detail

TypeFormat

private TypeFormat()

Default constructor (forbids derivation).

Method Detail

indexOf

public static int indexOf(java.lang.CharSequence pattern,
                          java.lang.CharSequence chars,
                          int fromIndex)

Searches for a particular sequence within a character sequence (general purpose parsing function).

Parameters:

pattern - the character sequence to search for.

chars - the character sequence being searched.

fromIndex - the index in chars to start the search from.

Returns:

the index in the range [fromIndex, chars.length()-pattern.length()] or -1 if the character sequence is not found.

parseBoolean

public static boolean parseBoolean(java.lang.CharSequence chars)

Parses the specified CharSequence as a boolean.

Parameters:

chars - the character sequence to parse.

Returns:

the corresponding boolean.

parseShort

public static short parseShort(java.lang.CharSequence chars)

Parses the specified CharSequence as a signed decimal short.

Parameters:

chars - the character sequence to parse.

Returns:

parseShort(chars, 10)

Throws:

java.lang.NumberFormatException - if the specified character sequence does not contain a parsable short.

See Also:

parseShort(CharSequence, int)

parseShort

public static short parseShort(java.lang.CharSequence chars,
                               int radix)

Parses the specified CharSequence as a signed short in the specified radix. The characters in the string must all be digits of the specified radix, except the first character which may be a plus sign '+' or a minus sign '-'.

Parameters:

chars - the character sequence to parse.

radix - the radix to be used while parsing.

Returns:

the corresponding short.

Throws:

java.lang.NumberFormatException - if the specified character sequence does not contain a parsable short.

parseInt

public static int parseInt(java.lang.CharSequence chars)

Parses the specified CharSequence as a signed decimal int.

Parameters:

chars - the character sequence to parse.

Returns:

parseInt(chars, 10)

Throws:

java.lang.NumberFormatException - if the specified character sequence does not contain a parsable int.

See Also:

parseInt(CharSequence, int)

parseInt

public static int parseInt(java.lang.CharSequence chars,
                           int radix)

Parses the specified CharSequence as a signed int in the specified radix. The characters in the string must all be digits of the specified radix, except the first character which may be a plus sign '+' or a minus sign '-'.

Parameters:

chars - the character sequence to parse.

radix - the radix to be used while parsing.

Returns:

the corresponding int.

Throws:

java.lang.NumberFormatException - if the specified character sequence does not contain a parsable int.

parseLong

public static long parseLong(java.lang.CharSequence chars)

Parses the specified CharSequence as a signed decimal long.

Parameters:

chars - the character sequence to parse.

Returns:

parseLong(chars, 10)

Throws:

java.lang.NumberFormatException - if the specified character sequence does not contain a parsable long.

See Also:

parseLong(CharSequence, int)

parseLong

public static long parseLong(java.lang.CharSequence chars,
                             int radix)

Parses the specified CharSequence as a signed long in the specified radix. The characters in the string must all be digits of the specified radix, except the first character which may be a plus sign '+' or a minus sign '-'.

Parameters:

chars - the character sequence to parse.

radix - the radix to be used while parsing.

Returns:

the corresponding long.

Throws:

java.lang.NumberFormatException - if the specified character sequence does not contain a parsable long.

parseFloat

public static float parseFloat(java.lang.CharSequence chars)

Parses this CharSequence as a float.

Parameters:

chars - the character sequence to parse.

Returns:

the float number represented by the specified character sequence.

Throws:

java.lang.NumberFormatException - if the character sequence does not contain a parsable float.

parseDouble

public static double parseDouble(java.lang.CharSequence chars)
                          throws java.lang.NumberFormatException

Parses this CharSequence as a double.

Parameters:

chars - the character sequence to parse.

Returns:

the double number represented by this character sequence.

Throws:

java.lang.NumberFormatException - if the character sequence does not contain a parsable double.

format

public static java.lang.StringBuffer format(boolean b,
                                            java.lang.StringBuffer sb)

Formats the specified boolean and appends the resulting text to the StringBuffer argument.

Parameters:

b - a boolean.

sb - the StringBuffer to append.

Returns:

the specified StringBuffer object.

See Also:

parseBoolean(java.lang.CharSequence)

format

public static java.lang.StringBuffer format(short s,
                                            java.lang.StringBuffer sb)

Formats the specified short and appends the resulting text (decimal representation) to the StringBuffer argument.

Note: This method is preferred to StringBuffer.append(short) as it does not create temporary String objects (several times faster for small numbers).

Parameters:

s - the short number.

sb - the StringBuffer to append.

Returns:

the specified StringBuffer object.

See Also:

parseShort(java.lang.CharSequence)

format

public static java.lang.StringBuffer format(short s,
                                            int radix,
                                            java.lang.StringBuffer sb)

Formats the specified short in the specified radix and appends the resulting text to the StringBuffer argument.

Parameters:

s - the short number.

radix - the radix.

sb - the StringBuffer to append.

Returns:

the specified StringBuffer object.

See Also:

throws IllegalArgumentException if radix is not in [2 .. 36] range.

format

public static java.lang.StringBuffer format(int i,
                                            java.lang.StringBuffer sb)

Formats the specified int and appends the resulting text (decimal representation) to the StringBuffer argument.

Note: This method is preferred to StringBuffer.append(int) as it does not create temporary String objects (several times faster for small numbers).

Parameters:

i - the int number.

sb - the StringBuffer to append.

Returns:

the specified StringBuffer object.

See Also:

parseInt(java.lang.CharSequence)

format

public static java.lang.StringBuffer format(int i,
                                            int radix,
                                            java.lang.StringBuffer sb)

Formats the specified int in the specified radix and appends the resulting text to the StringBuffer argument.

Parameters:

i - the int number.

radix - the radix.

sb - the StringBuffer to append.

Returns:

the specified StringBuffer object.

See Also:

throws IllegalArgumentException if radix is not in [2 .. 36] range.

format2

private static void format2(int i,
                            int radix,
                            java.lang.StringBuffer sb)

format

public static java.lang.StringBuffer format(long l,
                                            java.lang.StringBuffer sb)

Formats the specified long and appends the resulting text (decimal representation) to the StringBuffer argument.

Note: This method is preferred to StringBuffer.append(long) as it does not create temporary String objects (several times faster for small numbers).

Parameters:

l - the long number.

sb - the StringBuffer to append.

Returns:

the specified StringBuffer object.

See Also:

parseLong(java.lang.CharSequence)

format

public static java.lang.StringBuffer format(long l,
                                            int radix,
                                            java.lang.StringBuffer sb)

Formats the specified long in the specified radix and appends the resulting text to the StringBuffer argument.

Parameters:

l - the long number.

radix - the radix.

sb - the StringBuffer to append.

Returns:

the specified StringBuffer object.

See Also:

throws IllegalArgumentException if radix is not in [2 .. 36] range.

format2

private static void format2(long l,
                            int radix,
                            java.lang.StringBuffer sb)

format

public static java.lang.StringBuffer format(float f,
                                            java.lang.StringBuffer sb)

Formats the specified float and appends the resulting text to the StringBuffer argument.

Parameters:

f - the float number.

sb - the StringBuffer to append.

Returns:

format(f, 0.0f, sb)

See Also:

format(float, float, StringBuffer)

format

public static java.lang.StringBuffer format(float f,
                                            float precision,
                                            java.lang.StringBuffer sb)

Formats the specified float and appends the resulting text to the StringBuffer argument; the number of significative digits is deduced from the specified precision. All digits at least as significant as the specified precision are represented. For example:

• format(5.6f, 0.01f, sb) appends "5.60"
• format(5.6f, 0.1f, sb) appends "5.6"
• format(5.6f, 1f, sb) appends "6"

If the precision is 0.0f, the precision is assumed to be the intrinsic float precision (64 bits IEEE 754 format); no formatting is performed, all significant digits are displayed and trailing zeros are removed.

Parameters:

f - the float number.

precision - the maximum weight of the last digit represented.

sb - the StringBuffer to append.

Returns:

the specified StringBuffer object.

Throws:

java.lang.IllegalArgumentException - if the specified precision is negative or would result in too many digits (19+).

format

public static java.lang.StringBuffer format(double d,
                                            java.lang.StringBuffer sb)

Formats the specified double and appends the resulting text to the StringBuffer argument.

Note : This method is preferred to StringBuffer.append(double) or even String.valueOf(double) as it does not create temporary String or FloatingDecimal objects (several times faster, e.g. 15x faster for Double.MAX_VALUE).

Parameters:

d - the double number.

sb - the StringBuffer to append.

Returns:

format(d, 0.0, sb)

See Also:

format(double, double, StringBuffer)

format

public static java.lang.StringBuffer format(double d,
                                            int digits,
                                            java.lang.StringBuffer sb)

Formats the specified double and appends the resulting text to the StringBuffer argument; the number of significand digits is specified as integer argument.

Parameters:

d - the double number.

digits - the number of significand digits (excludes exponent).

sb - the StringBuffer to append.

Returns:

the specified StringBuffer object.

Throws:

java.lang.IllegalArgumentException - if the number of digits is not in range [1..19].

format

public static java.lang.StringBuffer format(double d,
                                            double precision,
                                            java.lang.StringBuffer sb)

Formats the specified double and appends the resulting text to the StringBuffer argument; the number of significative digits is deduced from the specified precision. All digits at least as significant as the specified precision are represented. For example:

• format(5.6, 0.01, sb) appends "5.60"
• format(5.6, 0.1, sb) appends "5.6"
• format(5.6, 1, sb) appends "6"

If the precision is 0.0, the precision is assumed to be the intrinsic double precision (64 bits IEEE 754 format); no formatting is performed, all significant digits are displayed and trailing zeros are removed.

Parameters:

d - the double number.

precision - the maximum weight of the last digit represented.

sb - the StringBuffer to append.

Returns:

the specified StringBuffer object.

Throws:

java.lang.IllegalArgumentException - if the specified precision is negative or would result in too many digits (19+).

format

private static java.lang.StringBuffer format(double d,
                                             double precision,
                                             boolean precisionOnLastDigit,
                                             java.lang.StringBuffer sb)

Formats the specified double and appends the resulting text to the StringBuffer argument; the number of significative digits is deduced from the specified precision.

Parameters:

d - the double number.

precision - the maximum weight of the last digit represented.

precisionOnLastDigit - indicates if the number of digits is deduced from the specified precision.

sb - the StringBuffer to append.

Returns:

the specified StringBuffer object.

multE

private static final double multE(double value,
                                  int E)

Returns the product of the specified value with 10 raised at the specified power exponent.

Parameters:

value - the value.

E - the exponent.

Returns:

value * 10^E