public void createUser(String username, String email, String password) {
        User user = new User();
        user.setUsername(username);
        user.setEmail(email);
        user.setPassword(new Sha256Hash(password).toHex());
        userDAO.createUser(user);
    }
Default implementation of the {@link UserService} interface.  This service implements
operations related to User data.
samples/spring-hibernate/src/main/java/org/apache/shiro/samples/sprhib/service/DefaultUserService.java