随机生成一个六位验证码工具类

随机生成一个由大小写字母和数字组成的六位验证码

import java.util.Random;

/**
 * 随机生成六位验证码工具类
 * @author: whh
 */
public class VerificationCodeUtil {

    public static String VerificationCode(){
        String str="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
        int codeLength=6;
        StringBuilder sb=new StringBuilder(6);
        for(int i=0;i<codeLength;i++)
        {
            char ch=str.charAt(new Random().nextInt(str.length()));
            sb.append(ch);
        }
        return (sb.toString());
    }
}