org.apache.commons.lang
Class NumberUtils

java.lang.Object
  |
  +--org.apache.commons.lang.NumberUtils

public final class NumberUtils
extends java.lang.Object

Provides extra functionality for java Number classes.

Version:
$Id: NumberUtils.java,v 1.1 2002/07/19 03:35:54 bayard Exp $
Author:
Henri Yandell, Rand McNeely, Stephen Colebourne

Constructor Summary
NumberUtils()
           
 
Method Summary
static java.math.BigDecimal createBigDecimal(java.lang.String val)
          Convert a String to a BigDecimal
static java.math.BigInteger createBigInteger(java.lang.String val)
          Convert a String to a BigInteger
static java.lang.Double createDouble(java.lang.String val)
          Convert a String to a Double
static java.lang.Float createFloat(java.lang.String val)
          Convert a String to a Float
static java.lang.Integer createInteger(java.lang.String val)
          Convert a String to a Integer, handling hex and octal notations.
static java.lang.Long createLong(java.lang.String val)
          Convert a String to a Long
static java.lang.Number createNumber(java.lang.String val)
           Turns a string value into a java.lang.Number.
private static boolean isAllZeros(java.lang.String s)
          Utility method for createNumber.
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 int maximum(int a, int b, int c)
          Get the maximum of three values.
static int minimum(int a, int b, int c)
          Get the minimum of three values.
static int stringToInt(java.lang.String str)
          Convert a String to an int, returning zero if the conversion fails
static int stringToInt(java.lang.String str, int defaultValue)
          Convert a String to an int, returning a default value if the conversion fails.
 
Methods inherited from class java.lang.Object
, clone, equals, finalize, getClass, hashCode, notify, notifyAll, registerNatives, toString, wait, wait, wait
 

Constructor Detail

NumberUtils

public NumberUtils()
Method Detail

stringToInt

public static int stringToInt(java.lang.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(java.lang.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

createNumber

public static java.lang.Number createNumber(java.lang.String val)
                                     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 succissively 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:
java.lang.NumberFormatException - if the value cannot be converted

isAllZeros

private static boolean isAllZeros(java.lang.String s)
Utility method for createNumber. Returns true if s is null
Parameters:
s - the String to check
Returns:
if it is all zeros or null

createFloat

public static java.lang.Float createFloat(java.lang.String val)
Convert a String to a Float
Parameters:
val - a String to convert
Returns:
converted Float
Throws:
java.lang.NumberFormatException - if the value cannot be converted

createDouble

public static java.lang.Double createDouble(java.lang.String val)
Convert a String to a Double
Parameters:
val - a String to convert
Returns:
converted Double
Throws:
java.lang.NumberFormatException - if the value cannot be converted

createInteger

public static java.lang.Integer createInteger(java.lang.String val)
Convert a String to a Integer, handling hex and octal notations.
Parameters:
val - a String to convert
Returns:
converted Integer
Throws:
java.lang.NumberFormatException - if the value cannot be converted

createLong

public static java.lang.Long createLong(java.lang.String val)
Convert a String to a Long
Parameters:
val - a String to convert
Returns:
converted Long
Throws:
java.lang.NumberFormatException - if the value cannot be converted

createBigInteger

public static java.math.BigInteger createBigInteger(java.lang.String val)
Convert a String to a BigInteger
Parameters:
val - a String to convert
Returns:
converted BigInteger
Throws:
java.lang.NumberFormatException - if the value cannot be converted

createBigDecimal

public static java.math.BigDecimal createBigDecimal(java.lang.String val)
Convert a String to a BigDecimal
Parameters:
val - a String to convert
Returns:
converted BigDecimal
Throws:
java.lang.NumberFormatException - if the value cannot be converted

minimum

public static int minimum(int a,
                          int b,
                          int c)
Get the minimum of three values.

maximum

public static int maximum(int a,
                          int b,
                          int c)
Get the maximum of three values.

isDigits

public static boolean isDigits(java.lang.String str)
Checks whether the String contains only digit characters. Null and blank string will return false.
Parameters:
str - the string to check
Returns:
boolean 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 blank string will return false.

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


Copyright (c) 2001-2002 - Apache Software Foundation