Generating a message authentication code six Java Java generating three random numbers

In the " Java generate three random numbers ", the brief describes how to use Java to generate three random numbers, a few days ago encountered generate six text messages at work needs verification code, verification code is composed of six random numbers, It does not contain letters. 6 SMS is generally used as the random number codes, reference code as follows:

String verifyCode = String.valueOf(new Random().nextInt(900000) + 100000);
System.out.println(verifyCode);