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 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)