org.springframework.util

Class NumberUtils

java.lang.Object

org.springframework.util.NumberUtils

public abstract class NumberUtils
extends java.lang.Object

Miscellaneous utility methods for number conversion and parsing.

Mainly for internal use within the framework; consider Apache's Commons Lang for a more comprehensive suite of number utilities.

Since:

1.1.2

Author:

Juergen Hoeller, Rob Harrop

Field Summary

Fields

Modifier and Type	Field and Description
private static java.math.BigInteger	LONG_MAX
private static java.math.BigInteger	LONG_MIN
static java.util.Set<java.lang.Class<?>>	STANDARD_NUMBER_TYPES Standard number types (all immutable): Byte, Short, Integer, Long, BigInteger, Float, Double, BigDecimal.

Constructor Summary

Constructors

Constructor and Description
NumberUtils()

Method Summary

Modifier and Type	Method and Description
private static long	checkedLongValue(java.lang.Number number, java.lang.Class<? extends java.lang.Number> targetClass) Check for a BigInteger/BigDecimal long overflow before returning the given number as a long value.
static <T extends java.lang.Number> T	convertNumberToTargetClass(java.lang.Number number, java.lang.Class<T> targetClass) Convert the given number into an instance of the given target class.
private static java.math.BigInteger	decodeBigInteger(java.lang.String value) Decode a BigInteger from the supplied String value.
private static boolean	isHexNumber(java.lang.String value) Determine whether the given value String indicates a hex number, i.e.
static <T extends java.lang.Number> T	parseNumber(java.lang.String text, java.lang.Class<T> targetClass) Parse the given text into a Number instance of the given target class, using the corresponding decode / valueOf method.
static <T extends java.lang.Number> T	parseNumber(java.lang.String text, java.lang.Class<T> targetClass, java.text.NumberFormat numberFormat) Parse the given text into a Number instance of the given target class, using the supplied NumberFormat.
private static void	raiseOverflowException(java.lang.Number number, java.lang.Class<?> targetClass) Raise an overflow exception for the given number and target class.

Methods inherited from class java.lang.Object

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

Field Detail

LONG_MIN

private static final java.math.BigInteger LONG_MIN

LONG_MAX

private static final java.math.BigInteger LONG_MAX

STANDARD_NUMBER_TYPES

public static final java.util.Set<java.lang.Class<?>> STANDARD_NUMBER_TYPES

Standard number types (all immutable): Byte, Short, Integer, Long, BigInteger, Float, Double, BigDecimal.

Constructor Detail

NumberUtils

public NumberUtils()

Method Detail

convertNumberToTargetClass

public static <T extends java.lang.Number> T convertNumberToTargetClass(java.lang.Number number,
                                                                        java.lang.Class<T> targetClass)
                                                                 throws java.lang.IllegalArgumentException

Convert the given number into an instance of the given target class.

Parameters:

number - the number to convert

targetClass - the target class to convert to

Returns:

the converted number

Throws:

java.lang.IllegalArgumentException - if the target class is not supported (i.e. not a standard Number subclass as included in the JDK)

See Also:

Byte, Short, Integer, Long, BigInteger, Float, Double, BigDecimal

checkedLongValue

private static long checkedLongValue(java.lang.Number number,
                                     java.lang.Class<? extends java.lang.Number> targetClass)

Check for a BigInteger/BigDecimal long overflow before returning the given number as a long value.

Parameters:

number - the number to convert

targetClass - the target class to convert to

Returns:

the long value, if convertible without overflow

Throws:

java.lang.IllegalArgumentException - if there is an overflow

See Also:

raiseOverflowException(java.lang.Number, java.lang.Class<?>)

raiseOverflowException

private static void raiseOverflowException(java.lang.Number number,
                                           java.lang.Class<?> targetClass)

Raise an overflow exception for the given number and target class.

Parameters:

number - the number we tried to convert

targetClass - the target class we tried to convert to

Throws:

java.lang.IllegalArgumentException - if there is an overflow

parseNumber

public static <T extends java.lang.Number> T parseNumber(java.lang.String text,
                                                         java.lang.Class<T> targetClass)

Parse the given text into a Number instance of the given target class, using the corresponding decode / valueOf method.

Trims all whitespace (leading, trailing, and in between characters) from the input String before attempting to parse the number.

Supports numbers in hex format (with leading "0x", "0X", or "#") as well.

Parameters:

text - the text to convert

targetClass - the target class to parse into

Returns:

the parsed number

Throws:

java.lang.IllegalArgumentException - if the target class is not supported (i.e. not a standard Number subclass as included in the JDK)

See Also:

Byte.decode(java.lang.String), Short.decode(java.lang.String), Integer.decode(java.lang.String), Long.decode(java.lang.String), decodeBigInteger(String), Float.valueOf(java.lang.String), Double.valueOf(java.lang.String), BigDecimal.BigDecimal(String)

parseNumber

public static <T extends java.lang.Number> T parseNumber(java.lang.String text,
                                                         java.lang.Class<T> targetClass,
                                                         @Nullable
                                                         java.text.NumberFormat numberFormat)

Parse the given text into a Number instance of the given target class, using the supplied NumberFormat.

Trims the input String before attempting to parse the number.

Parameters:

text - the text to convert

targetClass - the target class to parse into

numberFormat - the NumberFormat to use for parsing (if null, this method falls back to parseNumber(String, Class))

Returns:

the parsed number

Throws:

java.lang.IllegalArgumentException - if the target class is not supported (i.e. not a standard Number subclass as included in the JDK)

See Also:

NumberFormat.parse(java.lang.String, java.text.ParsePosition), convertNumberToTargetClass(java.lang.Number, java.lang.Class<T>), parseNumber(String, Class)

isHexNumber

private static boolean isHexNumber(java.lang.String value)

Determine whether the given value String indicates a hex number, i.e. needs to be passed into Integer.decode instead of Integer.valueOf, etc.

decodeBigInteger

private static java.math.BigInteger decodeBigInteger(java.lang.String value)

Decode a BigInteger from the supplied String value.

Supports decimal, hex, and octal notation.

See Also:

BigInteger.BigInteger(String, int)