org.apache.commons.lang

Class NumberUtils

public final class NumberUtils extends Object

Deprecated: Moved to org.apache.commons.lang.math. Class will be removed in Commons Lang 3.0.

Provides extra functionality for Java Number classes.

Since: 1.0

Version: $Id: NumberUtils.java 488819 2006-12-19 21:50:04Z bayard $

Author: Rand McNeely Stephen Colebourne Steve Downey Eric Pugh Phil Steitz

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. This method is more comprehensive than the standard Java greater than, less than and equals operators. It returns `-1` if the first value is less than the second.
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. It returns `-1` if the first value is less than the second.
static BigDecimal	createBigDecimal(String val) Convert a `String` to a `BigDecimal`.
static BigInteger	createBigInteger(String val) Convert a `String` to a `BigInteger`.
static Double	createDouble(String val) Convert a `String` to a `Double`.
static Float	createFloat(String val) Convert a `String` to a `Float`.
static Integer	createInteger(String val) Convert a `String` to a `Integer`, handling hex and octal notations.
static Long	createLong(String val) Convert a `String` to a `Long`.
static Number	createNumber(String val) 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'`).
static boolean	isDigits(String str) Checks whether the `String` contains only digit characters. `Null` and empty String will return `false`.
static boolean	isNumber(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.
static long	maximum(long a, long b, long c) Gets the maximum of three `long` values.
static int	maximum(int a, int b, int c) Gets the maximum of three `int` values.
static long	minimum(long a, long b, long c) Gets the minimum of three `long` values.
static int	minimum(int a, int b, int c) Gets the minimum of three `int` values.
static int	stringToInt(String str) Convert a `String` to an `int`, returning `zero` if the conversion fails.
static int	stringToInt(String str, int defaultValue) Convert a `String` to an `int`, returning a default value if the conversion fails.

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

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.

It returns -1 if the first value is less than the second.
It returns +1 if the first value is greater than the second.
It returns 0 if the values are equal.

The ordering is as follows, largest to smallest:

NaN
Positive infinity
Maximum double
Normal positive numbers
+0.0
-0.0
Normal negative numbers
Minimum double (-Double.MAX_VALUE)
Negative infinity

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.

It returns -1 if the first value is less than the second.
It returns +1 if the first value is greater than the second.
It returns 0 if the values are equal.

The ordering is as follows, largest to smallest:

NaN
Positive infinity
Maximum float
Normal positive numbers
+0.0
-0.0
Normal negative numbers
Minimum float (-Float.MAX_VALUE)
Negative infinity

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

createBigDecimal

public static BigDecimal createBigDecimal(String val)

Convert a String to a BigDecimal.

Parameters: val a String to convert

Returns: converted BigDecimal

Throws: NumberFormatException if the value cannot be converted

createBigInteger

public static BigInteger createBigInteger(String val)

Convert a String to a BigInteger.

Parameters: val a String to convert

Returns: converted BigInteger

Throws: NumberFormatException if the value cannot be converted

createDouble

public static Double createDouble(String val)

Convert a String to a Double.

Parameters: val a String to convert

Returns: converted Double

Throws: NumberFormatException if the value cannot be converted

createFloat

public static Float createFloat(String val)

Convert a String to a Float.

Parameters: val a String to convert

Returns: converted Float

Throws: NumberFormatException if the value cannot be converted

createInteger

public static Integer createInteger(String val)

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

Parameters: val a String to convert

Returns: converted Integer

Throws: NumberFormatException if the value cannot be converted

createLong

public static Long createLong(String val)

Convert a String to a Long.

Parameters: val a String to convert

Returns: converted Long

Throws: NumberFormatException if the value cannot be converted

createNumber

public static Number createNumber(String val)

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 hold 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.

Parameters: val String containing a number

Returns: Number created from the string

Throws: NumberFormatException if the value cannot be converted

isDigits

public static boolean isDigits(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(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

maximum

public static long maximum(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

maximum

public static int maximum(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

minimum

public static long minimum(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

minimum

public static int minimum(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

stringToInt

public static int stringToInt(String str)

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

Parameters: str the string to convert

Returns: the int represented by the string, or zero if conversion fails

stringToInt

public static int stringToInt(String str, int defaultValue)

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

Parameters: str the string to convert defaultValue the default value

Returns: the int represented by the string, or the default if conversion fails