简单工具类
写作初衷:由于日常开发经常需要用到很多工具类,经常根据需求自己写也比较麻烦
网上好了一些工具类例如commom.lang3或者hutool或者Jodd这样的开源工具,但是
发现他们之中虽然设计不错,但是如果我想要使用,就必须要引入依赖并且去维护依赖,有些
甚至会有存在版本编译不通过问题,故此想要写作一个每个类都可以作为独立工具类使用
每个使用者只需要复制该类,到任何项目当中都可以使用,所以需要尊从以下两个原则才能
做到.在此诚邀各位大佬参与.可以把各自用过的工具,整合成只依赖JDK,每个类都能够单独
使用的工具.每个人当遇到业务需求需要使用的时候,只需要到这里单独拷贝一个即可使用.
抛弃传统的需要引入依赖的烦恼.让大家一起来解决你所面临的业务问题吧!
介绍
遵从两大原则
- 1.绝不依赖JDK以外的源码
- 2.牺牲代码复用性,每个类都必须是单独的组件,绝不互相引用,做到完全解耦
package *;
import java.math.BigDecimal;
import java.math.BigInteger;
/**
* @program: simple_tools
* @description: 数字化工具类
* @author: ChenWenLong
* @create: 2019-06-06 16:23
**/
public class NumberUtils {
//long类型 0 1 -1
public static final Long LONG_ZERO = new Long(0L);
public static final Long LONG_ONE = new Long(1L);
public static final Long LONG_MINUS_ONE = new Long(-1L);
//Integer类型 0 1 -1
public static final Integer INTEGER_ZERO = new Integer(0);
public static final Integer INTEGER_ONE = new Integer(1);
public static final Integer INTEGER_MINUS_ONE = new Integer(-1);
//Short类型 0 1 -1
public static final Short SHORT_ZERO = new Short((short) 0);
public static final Short SHORT_ONE = new Short((short) 1);
public static final Short SHORT_MINUS_ONE = new Short((short) -1);
//Byte类型 0 1 -1
public static final Byte BYTE_ZERO = new Byte((byte) 0);
public static final Byte BYTE_ONE = new Byte((byte) 1);
public static final Byte BYTE_MINUS_ONE = new Byte((byte) -1);
//Double类型 0 1 -1
public static final Double DOUBLE_ZERO = new Double(0.0d);
public static final Double DOUBLE_ONE = new Double(1.0d);
public static final Double DOUBLE_MINUS_ONE = new Double(-1.0d);
//Float类型 0 1 -1
public static final Float FLOAT_ZERO = new Float(0.0f);
public static final Float FLOAT_ONE = new Float(1.0f);
public static final Float FLOAT_MINUS_ONE = new Float(-1.0f);
/**
* 功能描述:
* 〈String转int类型〉
*
* @params : [str]
* @return : int
* @author : cwl
* @date : 2019/6/6 16:32
*/
public static int stringToInt(String str) {
return toInt(str);
}
/**
* 功能描述:
* 〈str转int,当str为空,则返回默认值0〉
*
* @params : [str]
* @return : int
* @author : cwl
* @date : 2019/6/6 16:33
*/
public static int toInt(String str) {
return toInt(str, 0);
}
/**
* 功能描述:
* 〈str转int,当str为空,则返回默认值〉
*
* @params : [str, defaultValue]
* @return : int
* @author : cwl
* @date : 2019/6/6 16:34
*/
public static int stringToInt(String str, int defaultValue) {
return toInt(str, defaultValue);
}
/**
* 功能描述:
* 〈str转int,当str为空,则返回默认值〉
*
* @params : [str, defaultValue]
* @return : int
* @author : cwl
* @date : 2019/6/6 16:34
*/
public static int toInt(String str, int defaultValue) {
if(str == null) {
return defaultValue;
}
try {
return Integer.parseInt(str);
} catch (NumberFormatException nfe) {
return defaultValue;
}
}
/**
* 功能描述:
* 〈str转成int,不是字符串的使用0替换〉
*
* @params : [str, defaultValue]
* @return : int
* @author : cwl
* @date : 2019/6/6 16:36
*/
public static int toIntDefaultZero(String str){
char[] chars = str.toCharArray();
for (int i=0;i< chars.length;i++) {
//如果字符不是数字,则记录它的索引位置
if(chars[i] >= 48 && chars[i] <= 57){
continue;
}
chars[i]=48;
}
return Integer.valueOf(new String(chars));
}
/**
* 功能描述:
* 〈字符串转long类型〉
*
* @params : [str]
* @return : long
* @author : cwl
* @date : 2019/6/6 17:24
*/
public static long toLong(String str) {
return toLong(str, 0L);
}
/**
* 功能描述:
* 〈字符串转long类型,如果字符串为空,则返回默认值〉
*
* @params : [str, defaultValue]
* @return : long
* @author : cwl
* @date : 2019/6/6 17:24
*/
public static long toLong(String str, long defaultValue) {
if (str == null) {
return defaultValue;
}
try {
return Long.parseLong(str);
} catch (NumberFormatException nfe) {
return defaultValue;
}
}
/**
* 功能描述:
* 〈字符串转float类型〉
*
* @params : [str]
* @return : float
* @author : cwl
* @date : 2019/6/6 17:25
*/
public static float toFloat(String str) {
return toFloat(str, 0.0f);
}
/**
* 功能描述:
* 〈字符串转float类型,如果字符串为空,则返回默认值〉
*
* @params : [str, defaultValue]
* @return : float
* @author : cwl
* @date : 2019/6/6 17:25
*/
public static float toFloat(String str, float defaultValue) {
if (str == null) {
return defaultValue;
}
try {
return Float.parseFloat(str);
} catch (NumberFormatException nfe) {
return defaultValue;
}
}
/**
* 功能描述:
* 〈字符串转double类型〉
*
* @params : [str]
* @return : double
* @author : cwl
* @date : 2019/6/6 17:26
*/
public static double toDouble(String str) {
return toDouble(str, 0.0d);
}
/**
* 功能描述:
* 〈字符串转double类型,如果字符串为空,则返回默认值〉
*
* @params : [str, defaultValue]
* @return : double
* @author : cwl
* @date : 2019/6/6 17:26
*/
public static double toDouble(String str, double defaultValue) {
if (str == null) {
return defaultValue;
}
try {
return Double.parseDouble(str);
} catch (NumberFormatException nfe) {
return defaultValue;
}
}
/**
* 功能描述:
* 〈创建一个Number〉
*
* @params : [str]
* @return : java.lang.Number
* @author : cwl
* @date : 2019/6/6 17:33
*/
public static Number createNumber(String str) throws NumberFormatException {
if (str == null) {
return null;
}
if (null == str || str.length() == 0 || " ".equals(str)) {
throw new NumberFormatException("A blank string is not a valid number");
}
if (str.startsWith("--")) {
//对于Bigdecimal值的一种处理
return null;
}
if (str.startsWith("0x") || str.startsWith("-0x")) {
return createInteger(str);
}
char lastChar = str.charAt(str.length() - 1);
String mant;
String dec;
String exp;
int decPos = str.indexOf('.');
int expPos = str.indexOf('e') + str.indexOf('E') + 1;
if (decPos > -1) {
if (expPos > -1) {
if (expPos < decPos) {
throw new NumberFormatException(str + " is not a valid number.");
}
dec = str.substring(decPos + 1, expPos);
} else {
dec = str.substring(decPos + 1);
}
mant = str.substring(0, decPos);
} else {
if (expPos > -1) {
mant = str.substring(0, expPos);
} else {
mant = str;
}
dec = null;
}
if (!Character.isDigit(lastChar)) {
if (expPos > -1 && expPos < str.length() - 1) {
exp = str.substring(expPos + 1, str.length() - 1);
} else {
exp = null;
}
String numeric = str.substring(0, str.length() - 1);
boolean allZeros = isAllZeros(mant) && isAllZeros(exp);
switch (lastChar) {
case 'l' :
case 'L' :
if (dec == null
&& exp == null
&& (numeric.charAt(0) == '-' && isDigits(numeric.substring(1)) || isDigits(numeric))) {
try {
return createLong(numeric);
} catch (NumberFormatException nfe) {
//Too big for a long
}
return createBigInteger(numeric);
}
throw new NumberFormatException(str + " is not a valid number.");
case 'f' :
case 'F' :
try {
Float f = NumberUtils.createFloat(numeric);
if (!(f.isInfinite() || (f.floatValue() == 0.0F && !allZeros))) {
//如果浮点数太大，或者浮点值= 0，并且字符串中有非零，那么浮点数就没有我们想要的精度
return f;
}
} catch (NumberFormatException nfe) {
// 忽略非数字类型
}
// 顺序执行,无需break
case 'd' :
case 'D' :
try {
Double d = NumberUtils.createDouble(numeric);
if (!(d.isInfinite() || (d.floatValue() == 0.0D && !allZeros))) {
return d;
}
} catch (NumberFormatException nfe) {
// 忽略非数字类型
}
try {
return createBigDecimal(numeric);
} catch (NumberFormatException e) {
// 忽略非数字类型
}
// 顺序执行,无需break
default :
throw new NumberFormatException(str + " is not a valid number.");
}
} else {
if (expPos > -1 && expPos < str.length() - 1) {
exp = str.substring(expPos + 1, str.length());
} else {
exp = null;
}
if (dec == null && exp == null) {
//必须是int或者是long类型
try {
return createInteger(str);
} catch (NumberFormatException nfe) {
// ignore the bad number
}
try {
return createLong(str);
} catch (NumberFormatException nfe) {
// ignore the bad number
}
return createBigInteger(str);
} else {
//必须是float或者double或者bigdecmail
boolean allZeros = isAllZeros(mant) && isAllZeros(exp);
try {
Float f = createFloat(str);
if (!(f.isInfinite() || (f.floatValue() == 0.0F && !allZeros))) {
return f;
}
} catch (NumberFormatException nfe) {
// ignore the bad number
}
try {
Double d = createDouble(str);
if (!(d.isInfinite() || (d.doubleValue() == 0.0D && !allZeros))) {
return d;
}
} catch (NumberFormatException nfe) {
// ignore the bad number
}
return createBigDecimal(str);
}
}
}
/**
* 功能描述:
* 〈判断该字符串是否都是0〉
*
* @params : [str]
* @return : boolean
* @author : cwl
* @date : 2019/6/6 17:41
*/
private static boolean isAllZeros(String str) {
if (str == null) {
return true;
}
for (int i = str.length() - 1; i >= 0; i--) {
if (str.charAt(i) != '0') {
return false;
}
}
return str.length() > 0;
}
/**
* 功能描述:
* 〈str转float〉
*
* @params : [str]
* @return : java.lang.Float
* @author : cwl
* @date : 2019/6/6 17:42
*/
public static Float createFloat(String str) {
if (str == null) {
return null;
}
return Float.valueOf(str);
}
/**
* 功能描述:
* 〈str转double类型〉
*
* @params : [str]
* @return : java.lang.Double
* @author : cwl
* @date : 2019/6/6 17:42
*/
public static Double createDouble(String str) {
if (str == null) {
return null;
}
return Double.valueOf(str);
}
/**
* 功能描述:
* 〈str转Integer类型〉
*
* @params : [str]
* @return : java.lang.Integer
* @author : cwl
* @date : 2019/6/6 17:42
*/
public static Integer createInteger(String str) {
if (str == null) {
return null;
}
// decode() handles 0xAABD and 0777 (hex and octal) as well.
return Integer.decode(str);
}
/**
* 功能描述:
* 〈str转Long类型〉
*
* @params : [str]
* @return : java.lang.Long
* @author : cwl
* @date : 2019/6/6 17:43
*/
public static Long createLong(String str) {
if (str == null) {
return null;
}
return Long.valueOf(str);
}
/**
* 功能描述:
* 〈str转BigInteger〉
*
* @params : [str]
* @return : java.math.BigInteger
* @author : cwl
* @date : 2019/6/6 17:44
*/
public static BigInteger createBigInteger(String str) {
if (str == null) {
return null;
}
return new BigInteger(str);
}
/**
* 功能描述:
* 〈str转BigDecimal〉
*
* @params : [str]
* @return : java.math.BigDecimal
* @author : cwl
* @date : 2019/6/6 17:47
*/
public static BigDecimal createBigDecimal(String str) {
if (str == null) {
return null;
}
// 处理JDK1.3.1当中空字符串也会抛出索引越界异常问题
if (" ".equals(str.trim()) || str.length() == 0) {
throw new NumberFormatException("A blank string is not a valid number");
}
return new BigDecimal(str);
}
/**
* 功能描述:
* 〈返回long数组当中的最小值〉
*
* @params : [array]
* @return : long
* @author : cwl
* @date : 2019/6/6 17:47
*/
public static long min(long[] array) {
// Validates input
if (array == null) {
throw new IllegalArgumentException("The Array must not be null");
} else if (array.length == 0) {
throw new IllegalArgumentException("Array cannot be empty.");
}
// Finds and returns min
long min = array[0];
for (int i = 1; i < array.length; i++) {
if (array[i] < min) {
min = array[i];
}
}
return min;
}
/**
* 功能描述:
* 〈返回int数组当中的最小值〉
*
* @params : [array]
* @return : int
* @author : cwl
* @date : 2019/6/6 17:49
*/
public static int min(int[] array) {
// Validates input
if (array == null) {
throw new IllegalArgumentException("The Array must not be null");
} else if (array.length == 0) {
throw new IllegalArgumentException("Array cannot be empty.");
}
// Finds and returns min
int min = array[0];
for (int j = 1; j < array.length; j++) {
if (array[j] < min) {
min = array[j];
}
}
return min;
}
/**
* 功能描述:
* 〈返回short数组当中的最小值〉
*
* @params : [array]
* @return : short
* @author : cwl
* @date : 2019/6/6 17:49
*/
public static short min(short[] array) {
// Validates input
if (array == null) {
throw new IllegalArgumentException("The Array must not be null");
} else if (array.length == 0) {
throw new IllegalArgumentException("Array cannot be empty.");
}
// Finds and returns min
short min = array[0];
for (int i = 1; i < array.length; i++) {
if (array[i] < min) {
min = array[i];
}
}
return min;
}
/**
* 功能描述:
* 〈返回byte数组当中的最小值〉
*
* @params : [array]
* @return : byte
* @author : cwl
* @date : 2019/6/6 17:50
*/
public static byte min(byte[] array) {
// Validates input
if (array == null) {
throw new IllegalArgumentException("The Array must not be null");
} else if (array.length == 0) {
throw new IllegalArgumentException("Array cannot be empty.");
}
// Finds and returns min
byte min = array[0];
for (int i = 1; i < array.length; i++) {
if (array[i] < min) {
min = array[i];
}
}
return min;
}
/**
* 功能描述:
* 〈返回double数组中的最小值〉
*
* @params : [array]
* @return : double
* @author : cwl
* @date : 2019/6/6 17:50
*/
public static double min(double[] array) {
// Validates input
if (array == null) {
throw new IllegalArgumentException("The Array must not be null");
} else if (array.length == 0) {
throw new IllegalArgumentException("Array cannot be empty.");
}
// Finds and returns min
double min = array[0];
for (int i = 1; i < array.length; i++) {
if (Double.isNaN(array[i])) {
return Double.NaN;
}
if (array[i] < min) {
min = array[i];
}
}
return min;
}
/**
* 功能描述:
* 〈返回float数组中的最小值〉
*
* @params : [array]
* @return : float
* @author : cwl
* @date : 2019/6/6 17:50
*/
public static float min(float[] array) {
// Validates input
if (array == null) {
throw new IllegalArgumentException("The Array must not be null");
} else if (array.length == 0) {
throw new IllegalArgumentException("Array cannot be empty.");
}
// Finds and returns min
float min = array[0];
for (int i = 1; i < array.length; i++) {
if (Float.isNaN(array[i])) {
return Float.NaN;
}
if (array[i] < min) {
min = array[i];
}
}
return min;
}
/**
* 功能描述:
* 〈返回long数组的最大值〉
*
* @params : [array]
* @return : long
* @author : cwl
* @date : 2019/6/6 17:52
*/
public static long max(long[] array) {
// Validates input
if (array == null) {
throw new IllegalArgumentException("The Array must not be null");
} else if (array.length == 0) {
throw new IllegalArgumentException("Array cannot be empty.");
}
// Finds and returns max
long max = array[0];
for (int j = 1; j < array.length; j++) {
if (array[j] > max) {
max = array[j];
}
}
return max;
}
/**
* 功能描述:
* 〈返回int数组最大值〉
*
* @params : [array]
* @return : int
* @author : cwl
* @date : 2019/6/6 17:53
*/
public static int max(int[] array) {
// Validates input
if (array == null) {
throw new IllegalArgumentException("The Array must not be null");
} else if (array.length == 0) {
throw new IllegalArgumentException("Array cannot be empty.");
}
// Finds and returns max
int max = array[0];
for (int j = 1; j < array.length; j++) {
if (array[j] > max) {
max = array[j];
}
}
return max;
}
/**
* 功能描述:
* 〈返回short数组最大值〉
*
* @params : [array]
* @return : short
* @author : cwl
* @date : 2019/6/6 17:53
*/
public static short max(short[] array) {
// Validates input
if (array == null) {
throw new IllegalArgumentException("The Array must not be null");
} else if (array.length == 0) {
throw new IllegalArgumentException("Array cannot be empty.");
}
// Finds and returns max
short max = array[0];
for (int i = 1; i < array.length; i++) {
if (array[i] > max) {
max = array[i];
}
}
return max;
}
/**
* 功能描述:
* 〈返回byte数组最大值〉
*
* @params : [array]
* @return : byte
* @author : cwl
* @date : 2019/6/6 17:54
*/
public static byte max(byte[] array) {
// Validates input
if (array == null) {
throw new IllegalArgumentException("The Array must not be null");
} else if (array.length == 0) {
throw new IllegalArgumentException("Array cannot be empty.");
}
// Finds and returns max
byte max = array[0];
for (int i = 1; i < array.length; i++) {
if (array[i] > max) {
max = array[i];
}
}
return max;
}
/**
* 功能描述:
* 〈获取double数组最大值〉
*
* @params : [array]
* @return : double
* @author : cwl
* @date : 2019/6/6 17:54
*/
public static double max(double[] array) {
// Validates input
if (array== null) {
throw new IllegalArgumentException("The Array must not be null");
} else if (array.length == 0) {
throw new IllegalArgumentException("Array cannot be empty.");
}
// Finds and returns max
double max = array[0];
for (int j = 1; j < array.length; j++) {
if (Double.isNaN(array[j])) {
return Double.NaN;
}
if (array[j] > max) {
max = array[j];
}
}
return max;
}
/**
* 功能描述:
* 〈获取float数组最大值〉
*
* @params : [array]
* @return : float
* @author : cwl
* @date : 2019/6/6 17:55
*/
public static float max(float[] array) {
// Validates input
if (array == null) {
throw new IllegalArgumentException("The Array must not be null");
} else if (array.length == 0) {
throw new IllegalArgumentException("Array cannot be empty.");
}
// Finds and returns max
float max = array[0];
for (int j = 1; j < array.length; j++) {
if (Float.isNaN(array[j])) {
return Float.NaN;
}
if (array[j] > max) {
max = array[j];
}
}
return max;
}
/**
* 功能描述:
* 〈判断字符是否是纯数字〉
*
* @params : [str]
* @return : boolean
* @author : cwl
* @date : 2019/6/6 17:58
*/
public static boolean isDigits(String str) {
if (null == str || str.length() ==0 || " ".equals(str) ) {
return false;
}
for (int i = 0; i < str.length(); i++) {
if (!Character.isDigit(str.charAt(i))) {
return false;
}
}
return true;
}
/**
* 功能描述:
* 〈判断是否是一个数字类型〉
*
* @params : [str]
* @return : boolean
* @author : cwl
* @date : 2019/6/6 17:59
*/
public static boolean isNumber(String str) {
if (null == str || str.length() ==0 || " ".equals(str) ) {
return false;
}
char[] chars = str.toCharArray();
int sz = chars.length;
boolean hasExp = false;
boolean hasDecPoint = false;
boolean allowSigns = false;
boolean foundDigit = false;
// deal with any possible sign up front
int start = (chars[0] == '-') ? 1 : 0;
if (sz > start + 1) {
if (chars[start] == '0' && chars[start + 1] == 'x') {
int i = start + 2;
if (i == sz) {
return false; // str == "0x"
}
// checking hex (it can't be anything else)
for (; i < chars.length; i++) {
if ((chars[i] < '0' || chars[i] > '9')
&& (chars[i] < 'a' || chars[i] > 'f')
&& (chars[i] < 'A' || chars[i] > 'F')) {
return false;
}
}
return true;
}
}
sz--; // don't want to loop to the last char, check it afterwords
// for type qualifiers
int i = start;
// loop to the next to last char or to the last char if we need another digit to
// make a valid number (e.g. chars[0..5] = "1234E")
while (i < sz || (i < sz + 1 && allowSigns && !foundDigit)) {
if (chars[i] >= '0' && chars[i] <= '9') {
foundDigit = true;
allowSigns = false;
} else if (chars[i] == '.') {
if (hasDecPoint || hasExp) {
// two decimal points or dec in exponent
return false;
}
hasDecPoint = true;
} else if (chars[i] == 'e' || chars[i] == 'E') {
// we've already taken care of hex.
if (hasExp) {
// two E's
return false;
}
if (!foundDigit) {
return false;
}
hasExp = true;
allowSigns = true;
} else if (chars[i] == '+' || chars[i] == '-') {
if (!allowSigns) {
return false;
}
allowSigns = false;
foundDigit = false; // we need a digit after the E
} else {
return false;
}
i++;
}
if (i < chars.length) {
if (chars[i] >= '0' && chars[i] <= '9') {
// no type qualifier, OK
return true;
}
if (chars[i] == 'e' || chars[i] == 'E') {
// can't have an E at the last byte
return false;
}
if (!allowSigns
&& (chars[i] == 'd'
|| chars[i] == 'D'
|| chars[i] == 'f'
|| chars[i] == 'F')) {
return foundDigit;
}
if (chars[i] == 'l'
|| chars[i] == 'L') {
// not allowing L with an exponent
return foundDigit && !hasExp;
}
// last character is illegal
return false;
}
// allowSigns is true iff the val ends in 'E'
// found digit it to make sure weird stuff like '.' and '1E-' doesn't pass
return !allowSigns && foundDigit;
}
}
