grails spring-security create user - mongodb

Question

Im having some problems creating new user from one of my controllers. I'm trying to add a new user to my MongoDB user collection like this. Authorities is defined as a Set of Role in the domain.
Role role = new Role(authority:"ROLE_USER")
User user = new User(username:params.username,email:params.email,password:params.password,enabled:params.enabled,
accountExpired:params.accountExpired,accountLocked:params.accountLocked,passwordExpired:params.passwordExpired,
authorities:[role])
if (user.validate()) {
user.save(flush:true)
} else {
user.errors.allErrors.each { println it }
}
The exact same code is able to create a user successfully from the bootstrap, but when i'm trying to do the same thing from a simple controller i'm getting this error:
2012-09-24 10:43:27,450 [http-8080-3] ERROR binding.GrailsDataBinder - Unable to auto-create type interface java.util.Set, class java.lang.InstantiationException thrown in constructor
a:662)

Answer 1

Looks like the problem is with data binding. You have to create User with authorities first and then add role using UserRole domain. Something like:
Role role = Role.findByAuthority("ROLE_USER")
User user = new User(username:params.username,email:params.email,password:params.password,enabled:params.enabled, accountExpired:params.accountExpired,accountLocked:params.accountLocked,passwordExpired:params.passwordExpired)
new UserRole(user: user, role: role).save(flush: flush, insert: true)
user.save(flush:true)
For more information how to create user with spring security, you may want to look at Spring Security UI