程序包 cn.taketoday.util

类 NumberUtils

java.lang.Object

cn.taketoday.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.

从以下版本开始:

2018-07-06 13:36:29

作者:

Juergen Hoeller, Rob Harrop, Harry Yang

字段概要

字段

修饰符和类型	字段	说明
private static final BigInteger	LONG_MAX
private static final BigInteger	LONG_MIN
static final Set<Class<?>>	STANDARD_NUMBER_TYPES	Standard number types (all immutable): Byte, Short, Integer, Long, BigInteger, Float, Double, BigDecimal.

构造器概要

构造器

构造器	说明
NumberUtils()

方法概要

修饰符和类型	方法	说明
private static long	checkedLongValue(Number number, Class<? extends Number> targetClass)	Check for a BigInteger/BigDecimal long overflow before returning the given number as a long value.
static <T extends Number> T	convertNumberToTargetClass(Number number, Class<T> targetClass)	Convert the given number into an instance of the given target class.
private static BigInteger	decodeBigInteger(String value)	Decode a BigInteger from the supplied String value.
private static boolean	isHexNumber(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.
static boolean	isNumber(Class<?> targetClass)	Is a number?
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, NumberFormat numberFormat)	Parse the given text into a Number instance of the given target class, using the supplied NumberFormat.
private static void	raiseOverflowException(Number number, Class<?> targetClass)	Raise an overflow exception for the given number and target class.

从类继承的方法 java.lang.Object

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

字段详细资料

LONG_MIN

private static final BigInteger LONG_MIN

LONG_MAX

private static final BigInteger LONG_MAX

STANDARD_NUMBER_TYPES

public static final Set<Class<?>> STANDARD_NUMBER_TYPES

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

构造器详细资料

NumberUtils

public NumberUtils()

方法详细资料

isNumber

public static boolean isNumber(Class<?> targetClass)

Is a number?

参数:

targetClass - the target class

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.

参数:

number - the number to convert

targetClass - the target class to convert to

返回:

the converted number

抛出:

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

另请参阅:

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

checkedLongValue

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

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

参数:

number - the number to convert

targetClass - the target class to convert to

返回:

the long value, if convertible without overflow

抛出:

IllegalArgumentException - if there is an overflow

另请参阅:

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

raiseOverflowException

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

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

参数:

number - the number we tried to convert

targetClass - the target class we tried to convert to

抛出:

IllegalArgumentException - if there is an overflow

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 "#") as well.

参数:

text - the text to convert

targetClass - the target class to parse into

返回:

the parsed number

抛出:

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

另请参阅:

• 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(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.

参数:

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))

返回:

the parsed number

抛出:

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

另请参阅:

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

isHexNumber

private static boolean isHexNumber(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 BigInteger decodeBigInteger(String value)

Decode a BigInteger from the supplied String value.

Supports decimal, hex, and octal notation.

另请参阅:

• BigInteger(String, int)