package com.demo.common;
import java.util.Random;
/**
* @version:
* @function: 產生隨機數字、隨機字母、隨機數字+字母。
*/
public class RandomUtil {
/**
* 隨機產生幾位數字：例：maxLength=3,則結果可能是 012
*/
public static final int produceNumber(int maxLength){
Random random = new Random();
return random.nextInt(maxLength);
}
/**
* 隨機產生區間數字：例：minNumber=1,maxNumber=2,則結果可能是 1、2,包括首尾。
*/
public static int produceRegionNumber(int minNumber,int maxNumber){
return minNumber + produceNumber(maxNumber);
}
/**
* 隨機產生幾位字符串：例：maxLength=3,則結果可能是 aAz
* @param maxLength 傳入數必須是正數。
*/
public static String produceString(int maxLength){
String source = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
return doProduce(maxLength, source);
}
/**
* 隨機產生隨機數字+字母：例：maxLength=3,則結果可能是 1Az
* @param maxLength 傳入數必須是正數。
*/
public static String produceStringAndNumber(int maxLength){
String source = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
return doProduce(maxLength, source);
}
/**
* 自定義隨機產生結果
*/
public static String produceResultByCustom(String customString,int maxLength){
return doProduce(maxLength, customString);
}
/**
* 生產結果
*/
private static String doProduce(int maxLength, String source) {
StringBuffer sb = new StringBuffer(100);
for (int i = 0; i < maxLength; i++) {
final int number = produceNumber(source.length());
sb.append(source.charAt(number));
}
return sb.toString();
}
public static void main(String[] args) {
System.out.println(RandomUtil.produceNumber(3));
System.out.println(RandomUtil.produceRegionNumber(1,2));
System.out.println(RandomUtil.produceString(3));
System.out.println(RandomUtil.produceStringAndNumber(3));
System.out.println(RandomUtil.produceResultByCustom("demo.", 8));
}
}
原文地址：http://bbs.it-home.org/thread-1049-1-1.html