NumberKits (webfuse-core 1.0 API)

java.lang.Object
- cn.webfuse.framework.core.kit.NumberKits

```
public class NumberKits
extends Object
```
数字的工具类
copy from vipshop VJTools(com.vip.vjtools.vjkit.number.NumberUtil) and made some changes.

构造器概要

构造器
构造器和说明

NumberKits()

构造器
构造器和说明
`NumberKits()`

方法概要

所有方法静态方法具体方法
限定符和类型	方法和说明
`static <T extends Number> T`	`convertNumberToTargetClass(Number number, Class<T> targetClass)` 将给定的数字转换为给定目标类的实例
`static boolean`	`equalsWithin(double d1, double d2)` 因为double的精度问题, 允许两个double在0.00001内的误差为相等。
`static boolean`	`equalsWithin(double d1, double d2, double epsilon)` 因为double的精度问题, 允许两个double在epsilon内的误差为相等
`static boolean`	`isHexNumber(String value)` 判断字符串是否16进制
`static boolean`	`isNumber(String str)` 判断字符串是否合法数字
`static <T extends Number> T`	`parseNumber(Object val, Class<T> targetClass)` Parse the given `val` into a `Number` instance of the given target class, the default value is returned if an error occurs.
`static <T extends Number> T`	`parseNumber(Object val, Class<T> targetClass, T defaultValue)` Parse the given `val` into a `Number` instance of the given target class, the default value is returned if an error occurs.
`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 BigDecimal`	`round(Number number, int scale, RoundingMode roundingMode)` 保留固定位数小数例如保留四位小数：123.456789 =》 123.4567
`static BigDecimal`	`round(String number, int scale, RoundingMode roundingMode)` 保留固定位数小数例如保留四位小数：123.456789 =》 123.4567
`static String`	`to2DigitString(double d)` 输出格式化为小数后两位的double字符串
`static byte[]`	`toBytes(double val)` copy from ElasticSearch Numbers
`static byte[]`	`toBytes(int value)`
`static byte[]`	`toBytes(long value)`
`static double`	`toDouble(byte[] bytes)` copy from ElasticSearch Numbers
`static int`	`toInt(byte[] bytes)`
`static int`	`toInt32(long x)` 安全的将小于Integer.MAX的long转为int，否则抛出IllegalArgumentException异常
`static long`	`toLong(byte[] bytes)`
`static String`	`toString(double d)`
`static String`	`toString(Double d)`
`static String`	`toString(float f)`
`static String`	`toString(Float f)`
`static String`	`toString(int i)`
`static String`	`toString(Integer i)`
`static String`	`toString(long l)`
`static String`	`toString(Long l)`

从类继承的方法 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- 构造器详细资料
  - NumberKits
```
public NumberKits()
```
- 方法详细资料
  - equalsWithin
```
public static boolean equalsWithin(double d1,
                                   double d2)
```
    因为double的精度问题, 允许两个double在0.00001内的误差为相等。
  - equalsWithin
```
public static boolean equalsWithin(double d1,
                                   double d2,
                                   double epsilon)
```
    因为double的精度问题, 允许两个double在epsilon内的误差为相等
  - isNumber
```
public static boolean isNumber(String str)
```
    判断字符串是否合法数字
  - isHexNumber
```
public static boolean isHexNumber(String value)
```
    判断字符串是否16进制
  - convertNumberToTargetClass
```
public static <T extends Number> T convertNumberToTargetClass(Number number,
                                                              Class<T> targetClass)
                                                       throws IllegalArgumentException
```
    将给定的数字转换为给定目标类的实例
    
    参数:
    
    number - 将要转换的数字
    
    targetClass - 目标类
    
    返回:
    
    转换后的数字
    
    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
  - 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 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.BigDecimal(String)
  - parseNumber
```
public static <T extends Number> T parseNumber(Object val,
                                               Class<T> targetClass,
                                               T defaultValue)
```
    Parse the given val into a Number instance of the given target class, the default value is returned if an error occurs.
    Trims the input Object before attempting to parse the number.
    Supports numbers in hex format (with leading "0x", "0X", or "#") as well.
    
    参数:
    
    val - an object to convert
    
    targetClass - the target class to parse into
    
    defaultValue - an default value
    
    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.BigDecimal(String)
  - parseNumber
```
public static <T extends Number> T parseNumber(Object val,
                                               Class<T> targetClass)
```
    Parse the given val into a Number instance of the given target class, the default value is returned if an error occurs.
    Trims the input Object before attempting to parse the number.
    Supports numbers in hex format (with leading "0x", "0X", or "#") as well.
    
    参数:
    
    val - an object 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.BigDecimal(String)
  - toString
```
public static String toString(int i)
```
  - toString
```
public static String toString(Integer i)
```
  - toString
```
public static String toString(float f)
```
  - toString
```
public static String toString(Float f)
```
  - toString
```
public static String toString(long l)
```
  - toString
```
public static String toString(Long l)
```
  - toString
```
public static String toString(double d)
```
  - toString
```
public static String toString(Double d)
```
  - to2DigitString
```
public static String to2DigitString(double d)
```
    输出格式化为小数后两位的double字符串
  - round
```
public static BigDecimal round(Number number,
                               int scale,
                               RoundingMode roundingMode)
```
    保留固定位数小数
    例如保留四位小数：123.456789 =》 123.4567
    
    参数:
    
    number - 数字值
    
    scale - 保留小数位数，如果传入小于0，则默认0
    
    roundingMode - 保留小数的模式 RoundingMode，如果传入null则默认四舍五入
    
    返回:
    
    新值
  - round
```
public static BigDecimal round(String number,
                               int scale,
                               RoundingMode roundingMode)
```
    保留固定位数小数
    例如保留四位小数：123.456789 =》 123.4567
    
    参数:
    
    number - 数字值
    
    scale - 保留小数位数，如果传入小于0，则默认0
    
    roundingMode - 保留小数的模式 RoundingMode，如果传入null则默认四舍五入
    
    返回:
    
    新值
  - toInt32
```
public static int toInt32(long x)
```
    安全的将小于Integer.MAX的long转为int，否则抛出IllegalArgumentException异常
  - toBytes
```
public static byte[] toBytes(int value)
```
  - toBytes
```
public static byte[] toBytes(long value)
```
  - toBytes
```
public static byte[] toBytes(double val)
```
    copy from ElasticSearch Numbers
  - toInt
```
public static int toInt(byte[] bytes)
```
  - toLong
```
public static long toLong(byte[] bytes)
```
  - toDouble
```
public static double toDouble(byte[] bytes)
```
    copy from ElasticSearch Numbers

类 NumberKits

构造器概要

方法概要

从类继承的方法 java.lang.Object

构造器详细资料

NumberKits

方法详细资料

equalsWithin

equalsWithin

isNumber

isHexNumber

convertNumberToTargetClass

parseNumber

parseNumber

parseNumber

toString

toString

toString

toString

toString

toString

toString

toString

to2DigitString

round

round

toInt32

toBytes

toBytes

toBytes

toInt

toLong

toDouble