Grails user registration

UserRegistration.groovy

def registrationData = request.JSON
List errors = []

if (!registrationData.email) {
  errors.add('email')
}

if (User.countByUsername(registrationData.email) > 0) {
  errors.add('duplicate')
}

if (!registrationData.password) {
    errors.add('passwordMissing')
  } else if (registrationData.password.size() < 8) {
    errors.add('passwordLength')
  }

  if (!registrationData.password2) {
    errors.add('passwordMatchMissing')
  } else if (registrationData.password != registrationData.password2) {
    errors.add('passwordMatchFailed')
  }
  Boolean containsNumberAndLetter = (registrationData.password =~ /\p{Alpha}/) &&
    (registrationData.password =~ /\p{Digit}/)
  if(!containsNumberAndLetter) {
    errors.add('passwordContent')
  }
  
if (errors){
  response.setStatus(SC_PRECONDITION_FAILED)
  render errors as JSON
  return
}
  

User user = new User()
user.username = registrationData.email
user.password = registrationData.password
user.enabled = true
user.save(failOnError: true)

response.setStatus(SC_CREATED)
render [userId: user.id] as JSON