Injecting LdapTemplate to return user details inside a Grails service causes Null Pointer Exception

问题

I've been struggling with Spring Security LDAP for a while now, and just when I finally thought I had it beaten into submission, its tripped me up again.

The scenario: I'm having users log in using their organisation credentials, which I then check against the internal user database. If they don't exist, I create them locally and then set their local authorities (I can't touch the LDAP server, only authenticate against it - so I can't add the authorities there). This works fine... but I then want to add a couple of fields from LDAP - their full name and email address, and this is where it goes wrong.

I have LDAP searches working in a controller - using the following code (I've injected ldapTemplate further up):

def fullName = ldapTemplate.search("", "(uid=" + uid + "*)", new AttributesMapper() {
        @Override
        public Object mapFromAttributes(Attributes attrs) throws NamingException {
            return attrs.get("cn").get()
        }
    })

and this works perfectly. But when I replicate this code in a service that is called post-authentication the ldapTemplate is always null... I've tried a few different things, but I can't get it to populate properly... can anyone shed some light on why? I'm hoping its something stupid I'm doing since its 4:21am and I should have been in bed about 6 hours ago...

EDIT: Here is the service code as requested, thanks for taking a look Burt - its currently not very robust as I haven't got it working past simply creating a new local user - there is work to do on it yet.

package com.myPackage

import javax.naming.NamingException;
import javax.naming.directory.Attributes;
import javax.servlet.http.HttpServletRequest
import javax.servlet.http.HttpServletResponse

import org.codehaus.groovy.grails.plugins.springsecurity.SpringSecurityUtils
import org.springframework.ldap.core.AttributesMapper
import org.springframework.security.core.Authentication
import org.springframework.security.core.authority.GrantedAuthorityImpl
import org.springframework.security.web.authentication.AuthenticationSuccessHandler
import org.springframework.security.web.authentication.SavedRequestAwareAuthenticationSuccessHandler

import org.apache.commons.lang.RandomStringUtils

class PostAuthHandlerService implements AuthenticationSuccessHandler {

def springSecurityService
def ldapTemplate

private AuthenticationSuccessHandler target = new SavedRequestAwareAuthenticationSuccessHandler();
private List NO_ROLES = [new GrantedAuthorityImpl(SpringSecurityUtils.NO_ROLE)]

public void onAuthenticationSuccess(HttpServletRequest request,
        HttpServletResponse response, Authentication auth) {
    def username = auth.principal.getAt("username")
    User.withTransaction { status ->
        // Check to see if this user exists in the local db
        def user = User.findByUsername(username)
        if (!user) { // User doesn't exist yet, so create and make a user...
            def userRole = Role.findByAuthority('ROLE_USER') ?:
                    new Role(authority: 'ROLE_AM').save(failOnError: true)
            user = new User(
                    username: username,
                    password: auth.getCredentials() ?: placeholderPassword(),
                    displayName: getLdapDetails("username", "cn") ?: "",
                    email: getLdapDetails("username", "mail") ?: "",
                    enabled: true).save(failOnError: true)
            UserRole.create user, userRole
        }
        else {
            println("--- You exist already! Updating details")
            user.displayName = getLdapDetails("username", "cn") ?: ""
        }
        target.onAuthenticationSuccess(request, response, auth)
    }
}

def getLdapDetails(username, attr) {
    return ldapTemplate.search("", "(uid=$username*)", new AttributesMapper() {
        @Override
        public Object mapFromAttributes(Attributes attrs) throws NamingException {
            return attrs.get(attr).get()
        }
    })
}

def placeholderPassword () {
    // This is here because we also allow local logins for some users.  
    // If the password is not available, then create a big ugly one...
    return org.apache.commons.lang.RandomStringUtils.randomAlphanumeric(128)
}

public void proceed(HttpServletRequest request,
HttpServletResponse response, Authentication auth) {
    target.onAuthenticationSuccess(request, response, auth)
}

}

2nd Edit: I've been trying various different things - including trying to use springSecurityService.reauthenticate to get the local user to be used during the session rather than the LDAP one - and this bean is null as well... it seems like I can't inject any beans into my service at all.

I eventually found this post: http://burtbeckwith.com/blog/?p=993 which gave me a workaround and I now have it working... but I'd still like to know why it didn't in the first place... I have so much to learn in Grails - and its hard to know where to start.

Cheers in advance

Steve