Class NumberUtils

java.lang.Object

org.springframework.util.NumberUtils

public abstract class NumberUtils
extends 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	Description
static final Set<Class<?>>	STANDARD_NUMBER_TYPES	Standard number types (all immutable): Byte, Short, Integer, Long, BigInteger, Float, Double, BigDecimal.

Constructor Summary

Constructors

Constructor	Description
NumberUtils()

Method Summary

Modifier and Type	Method	Description
static <T extends Number> T	convertNumberToTargetClass(Number number, Class<T> targetClass)	Convert the given number into an instance of the given target class.
static <T extends Number> T	parseNumber(String text, 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 Number> T	parseNumber(String text, Class<T> targetClass, @Nullable NumberFormat numberFormat)	Parse the given text into a Number instance of the given target class, using the supplied NumberFormat.

Methods inherited from class Object

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

Field Details

STANDARD_NUMBER_TYPES

public static final Set<Class<?>> STANDARD_NUMBER_TYPES

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

Constructor Details

NumberUtils

public NumberUtils()

Method Details

convertNumberToTargetClass

public static <T extends Number> T convertNumberToTargetClass(Number number,
 Class<T> targetClass)
                                                       throws 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:

IllegalArgumentException - if the target class is not supported (i.e. not a standard Number subclass as included in the JDK), or if the number cannot be converted to an integral target class without overflow (including NaN and infinite floating-point values)

See Also:

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

parseNumber

public static <T extends Number> T parseNumber(String text,
 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 "#", optionally preceded by a "+" or "-" sign) as well.

Parameters:

text - the text to convert

targetClass - the target class to parse into

Returns:

the parsed number

Throws:

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

See Also:

• Byte.decode(String)
• Short.decode(String)
• Integer.decode(String)
• Long.decode(String)
• decodeBigInteger(String)
• Float.valueOf(String)
• Double.valueOf(String)
• BigDecimal(String)

parseNumber

public static <T extends Number> T parseNumber(String text,
 Class<T> targetClass,
 @Nullable 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:

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

See Also:

• NumberFormat.parse(String, ParsePosition)
• convertNumberToTargetClass(Number, Class)
• parseNumber(String, Class)