字母数字随机验证码

//创建输出所有范围的字符串
String arr = "0123456789abcdefghijklmnopqrstuvwxyzABCDENGHIJKLMNOPQRSTUVWXYZ";
        //创建随机数
		Random Num = new Random();
        //创建验证码数组
		char[] m = new char[6];//6:6位验证码数组
        //定义验证码字符串
		String code = "";
        //遍历验证码
		for (int i = 0; i < m.length; i++) {
			int num = Num.nextInt(62);
			m[i] = (char)arr.charAt(num);
			code = code +String.valueOf(m[i]);
		}
		System.out.println(code);
		System.out.print("请输入验证码：");
        //输入验证码
		Scanner put = new Scanner(System.in);
        //随机验证码与输入验证码全小写
		String input = put.nextLine().toLowerCase();
		String output = code.toLowerCase();
        //判断
		if(input.equals(output)){
			System.out.println("验证码正确");
		}else{
			System.out.println("验证码错误");
			
		}