package com.reyun.util; import java.util.Random; public class CharacterUtils { public static String getRandomString(int length){ String str="abcdefABCDEF0123456789"; Random random = new Random(); StringBuffer sb = new StringBuffer(); for(int i = 0 ; i < length; ++i){ int number = random.nextInt(22);//[0,62) sb.append(str.charAt(number)); } return sb.toString(); } }