com.github.sylphlike.framework.utils.general.RandomUtils Maven / Gradle / Ivy
package com.github.sylphlike.framework.utils.general;
import java.util.concurrent.ThreadLocalRandom;
/**
* time 10/09/2020 18:19 星期四 (dd/MM/YYYY HH:mm)
*
email [email protected]
*
* @author Gopal.pan
* @version 1.0.0
*/
public class RandomUtils {
/** 用于随机选的数字 */
public static final String BASE_NUMBER = "0123456789";
/** 用于随机选的字符 */
public static final String BASE_CHAR_LOWER = "abcdefghijklmnopqrstuvwxyz";
public static final String BASE_CHAR_UPPER = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
/** 用于随机选的字符和数字*/
public static final String BASE_MIX = BASE_CHAR_LOWER + BASE_NUMBER + BASE_CHAR_UPPER;
/**
* 获得指定范围内的随机数[min, max)
*
time 10:52 2021/1/5 (HH:mm yyyy/MM/dd)
*
email [email protected]
* @param min 最小数（包含）
* @param max 最大数（不包含）
* @return long
* @author Gopal.pan
*/
public static long betweenLongRandom(long min, long max) {
return getRandom().nextLong(min, max);
}
/**
* 获得指定范围内的随机数[min, max)
*
time 10:52 2021/1/5 (HH:mm yyyy/MM/dd)
*
email [email protected]
* @param min 最小数（包含）
* @param max 最大数（不包含）
* @return long
* @author Gopal.pan
*/
public static long betweenIntRandom(int min, int max) {
return getRandom().nextInt(min, max);
}
/**
* 获得一个随机的字符串
*
time 10:52 2021/1/5 (HH:mm yyyy/MM/dd)
*
email [email protected]
* @param baseString 随机字符选取的样本
* @param length 字符串的长度
* @return java.lang.String
* @author Gopal.pan
*/
public static String randomString(String baseString, int length) {
if (null == baseString || "".equals(baseString)) {
return "";
}
final StringBuilder sb = new StringBuilder(length);
if (length < 1) {
length = 1;
}
int baseLength = baseString.length();
for (int i = 0; i < length; i++) {
int number = randomInt(baseLength);
sb.append(baseString.charAt(number));
}
return sb.toString();
}
/**
* 获取指定长度的随机数字
*
time 10:51 2021/1/5 (HH:mm yyyy/MM/dd)
*
email [email protected]
* @param length 字符串的长度
* @return java.lang.String
* @author Gopal.pan
*/
public static String randomNumber(int length){
final StringBuilder sb = new StringBuilder(length);
int originLength = BASE_NUMBER.length();
for (int i = 0; i < length; i++) {
int number = randomInt(originLength);
sb.append(BASE_NUMBER.charAt(number));
}
return sb.toString();
}
/**
* 获取指定长度的小写字符
*
time 10:51 2021/1/5 (HH:mm yyyy/MM/dd)
*
email [email protected]
* @param length 字符串的长度
* @return java.lang.String
* @author Gopal.pan
*/
public static String randomCharLower(int length){
final StringBuilder sb = new StringBuilder(length);
int originLength = BASE_CHAR_LOWER.length();
for (int i = 0; i < length; i++) {
int number = randomInt(originLength);
sb.append(BASE_CHAR_LOWER.charAt(number));
}
return sb.toString();
}
/**
* 获取指定长度的小写字符
*
time 10:51 2021/1/5 (HH:mm yyyy/MM/dd)
*
email [email protected]
* @param length 字符串的长度
* @return java.lang.String
* @author Gopal.pan
*/
public static String randomCharUpper(int length){
final StringBuilder sb = new StringBuilder(length);
int originLength = BASE_CHAR_UPPER.length();
for (int i = 0; i < length; i++) {
int number = randomInt(originLength);
sb.append(BASE_CHAR_UPPER.charAt(number));
}
return sb.toString();
}
/**
* 获取指定长度的数字字母组合
*
time 10:50 2021/1/5 (HH:mm yyyy/MM/dd)
*
email [email protected]
* @param length 字符串的长度
* @return java.lang.String
* @author Gopal.pan
*/
public static String randomMix(int length){
final StringBuilder sb = new StringBuilder(length);
int originLength = BASE_MIX.length();
for (int i = 0; i < length; i++) {
int number = randomInt(originLength);
sb.append(BASE_MIX.charAt(number));
}
return sb.toString();
}
/**
* 获得指定范围内的随机数 [0,limit)
*
* @param limit 限制随机数的范围，不包括这个数
* @return 随机数
*/
public static int randomInt(int limit) {
return getRandom().nextInt(limit);
}
/**
* 获取随机数生成器对象
* ThreadLocalRandom是JDK 7之后提供并发产生随机数，能够解决多个线程发生的竞争争夺。
* @return {@link ThreadLocalRandom}
*/
public static ThreadLocalRandom getRandom() {
return ThreadLocalRandom.current();
}
}