org.apache.commons.lang.math
Class NumberUtils

java.lang.Object
  extended byorg.apache.commons.lang.math.NumberUtils

public class NumberUtils
extends java.lang.Object

Provides extra functionality for Java Number classes.

Since:
2.0
Version:
$Id: NumberUtils.java 609475 2008-01-06 23:58:59Z bayard $
Author:
Rand McNeely, Stephen Colebourne, Steve Downey, Eric Pugh, Phil Steitz, Matthew Hawthorne, Gary Gregory, Fredrik Westermarck

Field Summary
static java.lang.Byte BYTE_MINUS_ONE
          Reusable Byte constant for minus one.
static java.lang.Byte BYTE_ONE
          Reusable Byte constant for one.
static java.lang.Byte BYTE_ZERO
          Reusable Byte constant for zero.
static java.lang.Double DOUBLE_MINUS_ONE
          Reusable Double constant for minus one.
static java.lang.Double DOUBLE_ONE
          Reusable Double constant for one.
static java.lang.Double DOUBLE_ZERO
          Reusable Double constant for zero.
static java.lang.Float FLOAT_MINUS_ONE
          Reusable Float constant for minus one.
static java.lang.Float FLOAT_ONE
          Reusable Float constant for one.
static java.lang.Float FLOAT_ZERO
          Reusable Float constant for zero.
static java.lang.Integer INTEGER_MINUS_ONE
          Reusable Integer constant for minus one.
static java.lang.Integer INTEGER_ONE
          Reusable Integer constant for one.
static java.lang.Integer INTEGER_ZERO
          Reusable Integer constant for zero.
static java.lang.Long LONG_MINUS_ONE
          Reusable Long constant for minus one.
static java.lang.Long LONG_ONE
          Reusable Long constant for one.
static java.lang.Long LONG_ZERO
          Reusable Long constant for zero.
static java.lang.Short SHORT_MINUS_ONE
          Reusable Short constant for minus one.
static java.lang.Short SHORT_ONE
          Reusable Short constant for one.
static java.lang.Short SHORT_ZERO
          Reusable Short constant for zero.
 
Constructor Summary
NumberUtils()
          NumberUtils instances should NOT be constructed in standard programming.
 
Method Summary
static int compare(double lhs, double rhs)
          Compares two doubles for order.
static int compare(float lhs, float rhs)
          Compares two floats for order.
static java.math.BigDecimal createBigDecimal(java.lang.String str)
          Convert a String to a BigDecimal.
static java.math.BigInteger createBigInteger(java.lang.String str)
          Convert a String to a BigInteger.
static java.lang.Double createDouble(java.lang.String str)
          Convert a String to a Double.
static java.lang.Float createFloat(java.lang.String str)
          Convert a String to a Float.
static java.lang.Integer createInteger(java.lang.String str)
          Convert a String to a Integer, handling hex and octal notations.
static java.lang.Long createLong(java.lang.String str)
          Convert a String to a Long.
static java.lang.Number createNumber(java.lang.String str)
          Turns a string value into a java.lang.Number.
static boolean isDigits(java.lang.String str)
          Checks whether the String contains only digit characters.
static boolean isNumber(java.lang.String str)
          Checks whether the String a valid Java number.
static byte max(byte[] array)
          Returns the maximum value in an array.
static byte max(byte a, byte b, byte c)
          Gets the maximum of three byte values.
static double max(double[] array)
          Returns the maximum value in an array.
static double max(double a, double b, double c)
          Gets the maximum of three double values.
static float max(float[] array)
          Returns the maximum value in an array.
static float max(float a, float b, float c)
          Gets the maximum of three float values.
static int max(int[] array)
          Returns the maximum value in an array.
static int max(int a, int b, int c)
          Gets the maximum of three int values.
static long max(long[] array)
          Returns the maximum value in an array.
static long max(long a, long b, long c)
          Gets the maximum of three long values.
static short max(short[] array)
          Returns the maximum value in an array.
static short max(short a, short b, short c)
          Gets the maximum of three short values.
static byte min(byte[] array)
          Returns the minimum value in an array.
static byte min(byte a, byte b, byte c)
          Gets the minimum of three byte values.
static double min(double[] array)
          Returns the minimum value in an array.
static double min(double a, double b, double c)
          Gets the minimum of three double values.
static float min(float[] array)
          Returns the minimum value in an array.
static float min(float a, float b, float c)
          Gets the minimum of three float values.
static int min(int[] array)
          Returns the minimum value in an array.
static int min(int a, int b, int c)
          Gets the minimum of three int values.
static long min(long[] array)
          Returns the minimum value in an array.
static long min(long a, long b, long c)
          Gets the minimum of three long values.
static short min(short[] array)
          Returns the minimum value in an array.
static short min(short a, short b, short c)
          Gets the minimum of three short values.
static int stringToInt(java.lang.String str)
          Deprecated. Use toInt(String) This method will be removed in Commons Lang 3.0
static int stringToInt(java.lang.String str, int defaultValue)
          Deprecated. Use toInt(String, int) This method will be removed in Commons Lang 3.0
static double toDouble(java.lang.String str)
          Convert a String to a double, returning 0.0d if the conversion fails.
static double toDouble(java.lang.String str, double defaultValue)
          Convert a String to a double, returning a default value if the conversion fails.
static float toFloat(java.lang.String str)
          Convert a String to a float, returning 0.0f if the conversion fails.
static float toFloat(java.lang.String str, float defaultValue)
          Convert a String to a float, returning a default value if the conversion fails.
static int toInt(java.lang.String str)
          Convert a String to an int, returning zero if the conversion fails.
static int toInt(java.lang.String str, int defaultValue)
          Convert a String to an int, returning a default value if the conversion fails.
static long toLong(java.lang.String str)
          Convert a String to a long, returning zero if the conversion fails.
static long toLong(java.lang.String str, long defaultValue)
          Convert a String to a long, returning a default value if the conversion fails.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

LONG_ZERO

public static final java.lang.Long LONG_ZERO
Reusable Long constant for zero.


LONG_ONE

public static final java.lang.Long LONG_ONE
Reusable Long constant for one.


LONG_MINUS_ONE

public static final java.lang.Long LONG_MINUS_ONE
Reusable Long constant for minus one.


INTEGER_ZERO

public static final java.lang.Integer INTEGER_ZERO
Reusable Integer constant for zero.


INTEGER_ONE

public static final java.lang.Integer INTEGER_ONE
Reusable Integer constant for one.


INTEGER_MINUS_ONE

public static final java.lang.Integer INTEGER_MINUS_ONE
Reusable Integer constant for minus one.


SHORT_ZERO

public static final java.lang.Short SHORT_ZERO
Reusable Short constant for zero.


SHORT_ONE

public static final java.lang.Short SHORT_ONE
Reusable Short constant for one.


SHORT_MINUS_ONE

public static final java.lang.Short SHORT_MINUS_ONE
Reusable Short constant for minus one.


BYTE_ZERO

public static final java.lang.Byte BYTE_ZERO
Reusable Byte constant for zero.


BYTE_ONE

public static final java.lang.Byte BYTE_ONE
Reusable Byte constant for one.


BYTE_MINUS_ONE

public static final java.lang.Byte BYTE_MINUS_ONE
Reusable Byte constant for minus one.


DOUBLE_ZERO

public static final java.lang.Double DOUBLE_ZERO
Reusable Double constant for zero.


DOUBLE_ONE

public static final java.lang.Double DOUBLE_ONE
Reusable Double constant for one.


DOUBLE_MINUS_ONE

public static final java.lang.Double DOUBLE_MINUS_ONE
Reusable Double constant for minus one.


FLOAT_ZERO

public static final java.lang.Float FLOAT_ZERO
Reusable Float constant for zero.


FLOAT_ONE

public static final java.lang.Float FLOAT_ONE
Reusable Float constant for one.


FLOAT_MINUS_ONE

public static final java.lang.Float FLOAT_MINUS_ONE
Reusable Float constant for minus one.

Constructor Detail

NumberUtils

public NumberUtils()

NumberUtils instances should NOT be constructed in standard programming. Instead, the class should be used as NumberUtils.stringToInt("6");.

This constructor is public to permit tools that require a JavaBean instance to operate.

Method Detail

stringToInt

public static int stringToInt(java.lang.String str)
Deprecated. Use toInt(String) This method will be removed in Commons Lang 3.0

Convert a String to an int, returning zero if the conversion fails.

If the string is null, zero is returned.

   NumberUtils.stringToInt(null) = 0
   NumberUtils.stringToInt("")   = 0
   NumberUtils.stringToInt("1")  = 1
 

Parameters:
str - the string to convert, may be null
Returns:
the int represented by the string, or zero if conversion fails

toInt

public static int toInt(java.lang.String str)

Convert a String to an int, returning zero if the conversion fails.

If the string is null, zero is returned.

   NumberUtils.toInt(null) = 0
   NumberUtils.toInt("")   = 0
   NumberUtils.toInt("1")  = 1
 

Parameters:
str - the string to convert, may be null
Returns:
the int represented by the string, or zero if conversion fails
Since:
2.1

stringToInt

public static int stringToInt(java.lang.String str,
                              int defaultValue)
Deprecated. Use toInt(String, int) This method will be removed in Commons Lang 3.0

Convert a String to an int, returning a default value if the conversion fails.

If the string is null, the default value is returned.

   NumberUtils.stringToInt(null, 1) = 1
   NumberUtils.stringToInt("", 1)   = 1
   NumberUtils.stringToInt("1", 0)  = 1
 

Parameters:
str - the string to convert, may be null
defaultValue - the default value
Returns:
the int represented by the string, or the default if conversion fails

toInt

public static int toInt(java.lang.String str,
                        int defaultValue)

Convert a String to an int, returning a default value if the conversion fails.

If the string is null, the default value is returned.

   NumberUtils.toInt(null, 1) = 1
   NumberUtils.toInt("", 1)   = 1
   NumberUtils.toInt("1", 0)  = 1
 

Parameters:
str - the string to convert, may be null
defaultValue - the default value
Returns:
the int represented by the string, or the default if conversion fails
Since:
2.1

toLong

public static long toLong(java.lang.String str)

Convert a String to a long, returning zero if the conversion fails.

If the string is null, zero is returned.

   NumberUtils.toLong(null) = 0L
   NumberUtils.toLong("")   = 0L
   NumberUtils.toLong("1")  = 1L
 

Parameters:
str - the string to convert, may be null
Returns:
the long represented by the string, or 0 if conversion fails
Since:
2.1

toLong

public static long toLong(java.lang.String str,
                          long defaultValue)

Convert a String to a long, returning a default value if the conversion fails.

If the string is null, the default value is returned.

   NumberUtils.toLong(null, 1L) = 1L
   NumberUtils.toLong("", 1L)   = 1L
   NumberUtils.toLong("1", 0L)  = 1L
 

Parameters:
str - the string to convert, may be null
defaultValue - the default value
Returns:
the long represented by the string, or the default if conversion fails
Since:
2.1

toFloat

public static float toFloat(java.lang.String str)

Convert a String to a float, returning 0.0f if the conversion fails.

If the string str is null, 0.0f is returned.

   NumberUtils.toFloat(null)   = 0.0f
   NumberUtils.toFloat("")     = 0.0f
   NumberUtils.toFloat("1.5")  = 1.5f
 

Parameters:
str - the string to convert, may be null
Returns:
the float represented by the string, or 0.0f if conversion fails
Since:
2.1

toFloat

public static float toFloat(java.lang.String str,
                            float defaultValue)

Convert a String to a float, returning a default value if the conversion fails.

If the string str is null, the default value is returned.

   NumberUtils.toFloat(null, 1.1f)   = 1.0f
   NumberUtils.toFloat("", 1.1f)     = 1.1f
   NumberUtils.toFloat("1.5", 0.0f)  = 1.5f
 

Parameters:
str - the string to convert, may be null
defaultValue - the default value
Returns:
the float represented by the string, or defaultValue if conversion fails
Since:
2.1

toDouble

public static double toDouble(java.lang.String str)

Convert a String to a double, returning 0.0d if the conversion fails.

If the string str is null, 0.0d is returned.

   NumberUtils.toDouble(null)   = 0.0d
   NumberUtils.toDouble("")     = 0.0d
   NumberUtils.toDouble("1.5")  = 1.5d
 

Parameters:
str - the string to convert, may be null
Returns:
the double represented by the string, or 0.0d if conversion fails
Since:
2.1

toDouble

public static double toDouble(java.lang.String str,
                              double defaultValue)

Convert a String to a double, returning a default value if the conversion fails.

If the string str is null, the default value is returned.

   NumberUtils.toDouble(null, 1.1d)   = 1.1d
   NumberUtils.toDouble("", 1.1d)     = 1.1d
   NumberUtils.toDouble("1.5", 0.0d)  = 1.5d
 

Parameters:
str - the string to convert, may be null
defaultValue - the default value
Returns:
the double represented by the string, or defaultValue if conversion fails
Since:
2.1

createNumber

public static java.lang.Number createNumber(java.lang.String str)
                                     throws java.lang.NumberFormatException

Turns a string value into a java.lang.Number.

First, the value is examined for a type qualifier on the end ('f','F','d','D','l','L'). If it is found, it starts trying to create successively larger types from the type specified until one is found that can represent the value.

If a type specifier is not found, it will check for a decimal point and then try successively larger types from Integer to BigInteger and from Float to BigDecimal.

If the string starts with 0x or -0x, it will be interpreted as a hexadecimal integer. Values with leading 0's will not be interpreted as octal.

Returns null if the string is null.

This method does not trim the input string, i.e., strings with leading or trailing spaces will generate NumberFormatExceptions.

Parameters:
str - String containing a number, may be null
Returns:
Number created from the string
Throws:
java.lang.NumberFormatException - if the value cannot be converted

createFloat

public static java.lang.Float createFloat(java.lang.String str)

Convert a String to a Float.

Returns null if the string is null.

Parameters:
str - a String to convert, may be null
Returns:
converted Float
Throws:
java.lang.NumberFormatException - if the value cannot be converted

createDouble

public static java.lang.Double createDouble(java.lang.String str)

Convert a String to a Double.

Returns null if the string is null.

Parameters:
str - a String to convert, may be null
Returns:
converted Double
Throws:
java.lang.NumberFormatException - if the value cannot be converted

createInteger

public static java.lang.Integer createInteger(java.lang.String str)

Convert a String to a Integer, handling hex and octal notations.

Returns null if the string is null.

Parameters:
str - a String to convert, may be null
Returns:
converted Integer
Throws:
java.lang.NumberFormatException - if the value cannot be converted

createLong

public static java.lang.Long createLong(java.lang.String str)

Convert a String to a Long.

Returns null if the string is null.

Parameters:
str - a String to convert, may be null
Returns:
converted Long
Throws:
java.lang.NumberFormatException - if the value cannot be converted

createBigInteger

public static java.math.BigInteger createBigInteger(java.lang.String str)

Convert a String to a BigInteger.

Returns null if the string is null.

Parameters:
str - a String to convert, may be null
Returns:
converted BigInteger
Throws:
java.lang.NumberFormatException - if the value cannot be converted

createBigDecimal

public static java.math.BigDecimal createBigDecimal(java.lang.String str)

Convert a String to a BigDecimal.

Returns null if the string is null.

Parameters:
str - a String to convert, may be null
Returns:
converted BigDecimal
Throws:
java.lang.NumberFormatException - if the value cannot be converted

min

public static long min(long[] array)

Returns the minimum value in an array.

Parameters:
array - an array, must not be null or empty
Returns:
the minimum value in the array
Throws:
java.lang.IllegalArgumentException - if array is null
java.lang.IllegalArgumentException - if array is empty

min

public static int min(int[] array)

Returns the minimum value in an array.

Parameters:
array - an array, must not be null or empty
Returns:
the minimum value in the array
Throws:
java.lang.IllegalArgumentException - if array is null
java.lang.IllegalArgumentException - if array is empty

min

public static short min(short[] array)

Returns the minimum value in an array.

Parameters:
array - an array, must not be null or empty
Returns:
the minimum value in the array
Throws:
java.lang.IllegalArgumentException - if array is null
java.lang.IllegalArgumentException - if array is empty

min

public static byte min(byte[] array)

Returns the minimum value in an array.

Parameters:
array - an array, must not be null or empty
Returns:
the minimum value in the array
Throws:
java.lang.IllegalArgumentException - if array is null
java.lang.IllegalArgumentException - if array is empty

min

public static double min(double[] array)

Returns the minimum value in an array.

Parameters:
array - an array, must not be null or empty
Returns:
the minimum value in the array
Throws:
java.lang.IllegalArgumentException - if array is null
java.lang.IllegalArgumentException - if array is empty
See Also:
IEEE754rUtils for a version of this method that handles NaN differently

min

public static float min(float[] array)

Returns the minimum value in an array.

Parameters:
array - an array, must not be null or empty
Returns:
the minimum value in the array
Throws:
java.lang.IllegalArgumentException - if array is null
java.lang.IllegalArgumentException - if array is empty
See Also:
IEEE754rUtils for a version of this method that handles NaN differently

max

public static long max(long[] array)

Returns the maximum value in an array.

Parameters:
array - an array, must not be null or empty
Returns:
the minimum value in the array
Throws:
java.lang.IllegalArgumentException - if array is null
java.lang.IllegalArgumentException - if array is empty

max

public static int max(int[] array)

Returns the maximum value in an array.

Parameters:
array - an array, must not be null or empty
Returns:
the minimum value in the array
Throws:
java.lang.IllegalArgumentException - if array is null
java.lang.IllegalArgumentException - if array is empty

max

public static short max(short[] array)

Returns the maximum value in an array.

Parameters:
array - an array, must not be null or empty
Returns:
the minimum value in the array
Throws:
java.lang.IllegalArgumentException - if array is null
java.lang.IllegalArgumentException - if array is empty

max

public static byte max(byte[] array)

Returns the maximum value in an array.

Parameters:
array - an array, must not be null or empty
Returns:
the minimum value in the array
Throws:
java.lang.IllegalArgumentException - if array is null
java.lang.IllegalArgumentException - if array is empty

max

public static double max(double[] array)

Returns the maximum value in an array.

Parameters:
array - an array, must not be null or empty
Returns:
the minimum value in the array
Throws:
java.lang.IllegalArgumentException - if array is null
java.lang.IllegalArgumentException - if array is empty
See Also:
IEEE754rUtils for a version of this method that handles NaN differently

max

public static float max(float[] array)

Returns the maximum value in an array.

Parameters:
array - an array, must not be null or empty
Returns:
the minimum value in the array
Throws:
java.lang.IllegalArgumentException - if array is null
java.lang.IllegalArgumentException - if array is empty
See Also:
IEEE754rUtils for a version of this method that handles NaN differently

min

public static long min(long a,
                       long b,
                       long c)

Gets the minimum of three long values.

Parameters:
a - value 1
b - value 2
c - value 3
Returns:
the smallest of the values

min

public static int min(int a,
                      int b,
                      int c)

Gets the minimum of three int values.

Parameters:
a - value 1
b - value 2
c - value 3
Returns:
the smallest of the values

min

public static short min(short a,
                        short b,
                        short c)

Gets the minimum of three short values.

Parameters:
a - value 1
b - value 2
c - value 3
Returns:
the smallest of the values

min

public static byte min(byte a,
                       byte b,
                       byte c)

Gets the minimum of three byte values.

Parameters:
a - value 1
b - value 2
c - value 3
Returns:
the smallest of the values

min

public static double min(double a,
                         double b,
                         double c)

Gets the minimum of three double values.

If any value is NaN, NaN is returned. Infinity is handled.

Parameters:
a - value 1
b - value 2
c - value 3
Returns:
the smallest of the values
See Also:
for a version of this method that handles NaN differently

min

public static float min(float a,
                        float b,
                        float c)

Gets the minimum of three float values.

If any value is NaN, NaN is returned. Infinity is handled.

Parameters:
a - value 1
b - value 2
c - value 3
Returns:
the smallest of the values
See Also:
for a version of this method that handles NaN differently

max

public static long max(long a,
                       long b,
                       long c)

Gets the maximum of three long values.

Parameters:
a - value 1
b - value 2
c - value 3
Returns:
the largest of the values

max

public static int max(int a,
                      int b,
                      int c)

Gets the maximum of three int values.

Parameters:
a - value 1
b - value 2
c - value 3
Returns:
the largest of the values

max

public static short max(short a,
                        short b,
                        short c)

Gets the maximum of three short values.

Parameters:
a - value 1
b - value 2
c - value 3
Returns:
the largest of the values

max

public static byte max(byte a,
                       byte b,
                       byte c)

Gets the maximum of three byte values.

Parameters:
a - value 1
b - value 2
c - value 3
Returns:
the largest of the values

max

public static double max(double a,
                         double b,
                         double c)

Gets the maximum of three double values.

If any value is NaN, NaN is returned. Infinity is handled.

Parameters:
a - value 1
b - value 2
c - value 3
Returns:
the largest of the values
See Also:
for a version of this method that handles NaN differently

max

public static float max(float a,
                        float b,
                        float c)

Gets the maximum of three float values.

If any value is NaN, NaN is returned. Infinity is handled.

Parameters:
a - value 1
b - value 2
c - value 3
Returns:
the largest of the values
See Also:
for a version of this method that handles NaN differently

compare

public static int compare(double lhs,
                          double rhs)

Compares two doubles for order.

This method is more comprehensive than the standard Java greater than, less than and equals operators.

The ordering is as follows, largest to smallest:

Comparing NaN with NaN will return 0.

Parameters:
lhs - the first double
rhs - the second double
Returns:
-1 if lhs is less, +1 if greater, 0 if equal to rhs

compare

public static int compare(float lhs,
                          float rhs)

Compares two floats for order.

This method is more comprehensive than the standard Java greater than, less than and equals operators.

The ordering is as follows, largest to smallest:

Comparing NaN with NaN will return 0.

Parameters:
lhs - the first float
rhs - the second float
Returns:
-1 if lhs is less, +1 if greater, 0 if equal to rhs

isDigits

public static boolean isDigits(java.lang.String str)

Checks whether the String contains only digit characters.

Null and empty String will return false.

Parameters:
str - the String to check
Returns:
true if str contains only unicode numeric

isNumber

public static boolean isNumber(java.lang.String str)

Checks whether the String a valid Java number.

Valid numbers include hexadecimal marked with the 0x qualifier, scientific notation and numbers marked with a type qualifier (e.g. 123L).

Null and empty String will return false.

Parameters:
str - the String to check
Returns:
true if the string is a correctly formatted number


Copyright 2001-2008 The Apache Software Foundation. All Rights Reserved.