SpringSecurity UserDetailsService get password

I'm creating authentication service in Spring.

I'm using UserDetailsService to get form variables, but i found that loadUserByUsername has only one variable - userName.

How to get password ?

public class userAuthentication implements UserDetailsService{

    private @Autowired
    ASPWebServicesUtils aspWebServicesUtils;

    @Override
    public UserDetails loadUserByUsername(String name) throws UsernameNotFoundException {

        //how to get password ?

        User user = new User("test", "test", true, true, true, true, getAuthorities(true));

        return user;  

    }

    private List<GrantedAuthority> getAuthorities(boolean isAdmin){

        List<GrantedAuthority> authorityList = new ArrayList<GrantedAuthority>(2);
        authorityList.add(new SimpleGrantedAuthority("USER_ROLE"));
        if(isAdmin){
            authorityList.add(new SimpleGrantedAuthority("ADMIN_ROLE"));
        }
        return authorityList;

    }
//...
}

Thanks