使用Java获取特定Active Directory组的成员

Question

我正在尝试通过这段代码来获取特定组的成员列表：

    List<String> usersList = new ArrayList<String>();

    String[] attrIDs = { "distinguishedName","cn","name","uid",
                         "sn",
                         "givenname",
                         "memberOf",
                         "samaccountname",
                         "userPrincipalName" };

    SearchControls ctls = new SearchControls();
    ctls.setReturningAttributes(attrIDs);       
    ctls.setSearchScope(SearchControls.SUBTREE_SCOPE); 

    String filter = "(&(objectCategory=user)((memberOf=cn="+group_to_search+",ou=Groups,ou=XXX,dc=domain,dc=com)))";

    NamingEnumeration answer = ldapDir.search( base, filter, ctls );
    SearchResult rslt = (SearchResult)answer.next();          
    Attributes attrs = rslt.getAttributes();
    String mo = String.valueOf(attrs.get("name"));
    String[] groups = mo.split(",");
    for(int i=0; i<groups.length; i++){
        if(groups[i].contains("CN=")){
            String user = groups[i].replace("CN=", "").replace("memberOf:", "").trim();
            System.out.println(user);
            usersList.add(group);
        }           
    }

但是，尽管有20个用户，但似乎我只是获得group_to_search的第一个成员及其所有属性