NumberUtils (Lang 2.3 API)

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org.apache.commons.lang.math
Class NumberUtils

java.lang.Object
  org.apache.commons.lang.math.NumberUtils

public class NumberUtils
extends Object
extends Object

Provides extra functionality for Java Number classes.

Since:: 2.0
Version:: $Id: NumberUtils.java 491076 2006-12-29 18:48:37Z bayard $
Author:: Rand McNeely, Stephen Colebourne, Steve Downey, Eric Pugh, Phil Steitz, Matthew Hawthorne, Gary Gregory, Fredrik Westermarck

Field Summary
`static Byte`	`BYTE_MINUS_ONE` Reusable Byte constant for minus one.
`static Byte`	`BYTE_ONE` Reusable Byte constant for one.
`static Byte`	`BYTE_ZERO` Reusable Byte constant for zero.
`static Double`	`DOUBLE_MINUS_ONE` Reusable Double constant for minus one.
`static Double`	`DOUBLE_ONE` Reusable Double constant for one.
`static Double`	`DOUBLE_ZERO` Reusable Double constant for zero.
`static Float`	`FLOAT_MINUS_ONE` Reusable Float constant for minus one.
`static Float`	`FLOAT_ONE` Reusable Float constant for one.
`static Float`	`FLOAT_ZERO` Reusable Float constant for zero.
`static Integer`	`INTEGER_MINUS_ONE` Reusable Integer constant for minus one.
`static Integer`	`INTEGER_ONE` Reusable Integer constant for one.
`static Integer`	`INTEGER_ZERO` Reusable Integer constant for zero.
`static Long`	`LONG_MINUS_ONE` Reusable Long constant for minus one.
`static Long`	`LONG_ONE` Reusable Long constant for one.
`static Long`	`LONG_ZERO` Reusable Long constant for zero.
`static Short`	`SHORT_MINUS_ONE` Reusable Short constant for minus one.
`static Short`	`SHORT_ONE` Reusable Short constant for one.
`static 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 BigDecimal`	`createBigDecimal(String str)` Convert a `String` to a `BigDecimal`.
`static BigInteger`	`createBigInteger(String str)` Convert a `String` to a `BigInteger`.
`static Double`	`createDouble(String str)` Convert a `String` to a `Double`.
`static Float`	`createFloat(String str)` Convert a `String` to a `Float`.
`static Integer`	`createInteger(String str)` Convert a `String` to a `Integer`, handling hex and octal notations.
`static Long`	`createLong(String str)` Convert a `String` to a `Long`.
`static Number`	`createNumber(String str)` Turns a string value into a java.lang.Number.
`static boolean`	`isDigits(String str)` Checks whether the `String` contains only digit characters.
`static boolean`	`isNumber(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(String str)` Deprecated. Use `toInt(String)` This method will be removed in Commons Lang 3.0
`static int`	`stringToInt(String str, int defaultValue)` Deprecated. Use `toInt(String, int)` This method will be removed in Commons Lang 3.0
`static double`	`toDouble(String str)` Convert a `String` to a `double`, returning `0.0d` if the conversion fails.
`static double`	`toDouble(String str, double defaultValue)` Convert a `String` to a `double`, returning a default value if the conversion fails.
`static float`	`toFloat(String str)` Convert a `String` to a `float`, returning `0.0f` if the conversion fails.
`static float`	`toFloat(String str, float defaultValue)` Convert a `String` to a `float`, returning a default value if the conversion fails.
`static int`	`toInt(String str)` Convert a `String` to an `int`, returning `zero` if the conversion fails.
`static int`	`toInt(String str, int defaultValue)` Convert a `String` to an `int`, returning a default value if the conversion fails.
`static long`	`toLong(String str)` Convert a `String` to a `long`, returning `zero` if the conversion fails.
`static long`	`toLong(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 Long LONG_ZERO

Reusable Long constant for zero.

LONG_ONE

public static final Long LONG_ONE

Reusable Long constant for one.

LONG_MINUS_ONE

public static final Long LONG_MINUS_ONE

Reusable Long constant for minus one.

INTEGER_ZERO

public static final Integer INTEGER_ZERO

Reusable Integer constant for zero.

INTEGER_ONE

public static final Integer INTEGER_ONE

Reusable Integer constant for one.

INTEGER_MINUS_ONE

public static final Integer INTEGER_MINUS_ONE

Reusable Integer constant for minus one.

SHORT_ZERO

public static final Short SHORT_ZERO

Reusable Short constant for zero.

SHORT_ONE

public static final Short SHORT_ONE

Reusable Short constant for one.

SHORT_MINUS_ONE

public static final Short SHORT_MINUS_ONE

Reusable Short constant for minus one.

BYTE_ZERO

public static final Byte BYTE_ZERO

Reusable Byte constant for zero.

BYTE_ONE

public static final Byte BYTE_ONE

Reusable Byte constant for one.

BYTE_MINUS_ONE

public static final Byte BYTE_MINUS_ONE

Reusable Byte constant for minus one.

DOUBLE_ZERO

public static final Double DOUBLE_ZERO

Reusable Double constant for zero.

DOUBLE_ONE

public static final Double DOUBLE_ONE

Reusable Double constant for one.

DOUBLE_MINUS_ONE

public static final Double DOUBLE_MINUS_ONE

Reusable Double constant for minus one.

FLOAT_ZERO

public static final Float FLOAT_ZERO

Reusable Float constant for zero.

FLOAT_ONE

public static final Float FLOAT_ONE

Reusable Float constant for one.

FLOAT_MINUS_ONE

public static final 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(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(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(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(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(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(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(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(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(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(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 Number createNumber(String str)
                           throws 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.