The below search term seems to return match if a user simply exists in the active directory:
NamingEnumeration<SearchResult> ne = dirContext.search(
baseDN,
userObjectQuery,
new String[] { userName },
SearchControls)
The userObjectQuery is like userObjectQuery=(&(sAMAccountName=%u)(objectclass=user))
Where %u
above will be substituted by the username.
How do I make sure that the users password also matches and only then return true?