How To List Contents from a LDAP.

Love it or hate it  so many organization use LDAP sometimes you just can’t escape it .

For one of my clients I had to migrate the roles from a LDAP to Database .

As an intermediate step I wrote a method to buid a username , groupName map

The usernames were under the attribute uid, the groups were under the attribute groups

Code Exaple : 

 private static Map<String,List<String>> userNameRolesMap = new HashMap<String,List<String>>();

 private static void populateUsernameRoleMap() throws NamingException{

        Hashtable env = new Hashtable();

        String PROVIDER_URL = "";

        String SECURITY_PRINCIPAL = "";

        String SECURITY_CREDENTIALS = "";

        if(Constants.RUN_MODE == RunMode.DEV) {

            PROVIDER_URL = "ldap://" + Constants.DEV_HOST + ":" + Constants.DEV_PORT + "/" + Constants.DEV_BASEDN;

            SECURITY_PRINCIPAL = Constants.DEV_USER;

            SECURITY_CREDENTIALS = Constants.DEV_PASSWORD;

        }

            env.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.ldap.LdapCtxFactory");

            env.put(Context.PROVIDER_URL, PROVIDER_URL);

            env.put(Context.SECURITY_AUTHENTICATION, "simple");

            env.put(Context.SECURITY_PRINCIPAL, SECURITY_PRINCIPAL );

            env.put(Context.SECURITY_CREDENTIALS, SECURITY_CREDENTIALS);

        DirContext ctx = null;

        NamingEnumeration results = null;

        SearchControls controls = new SearchControls();

        controls.setSearchScope(SearchControls.SUBTREE_SCOPE);

        controls.setCountLimit(10000);

        try {

            ctx = new InitialDirContext(env);

           

            results = ctx.search("", "(objectclass=auspostUser)", controls);

            while (results.hasMore()) {

                SearchResult searchResult = (SearchResult) results.next();

                Attributes attributes = searchResult.getAttributes();

                Attribute userNameAttr = attributes.get("uid");

                String username = (String) userNameAttr.get();

                Attribute groupsAttr = attributes.get("groups");

                int numberOfRoles = groupsAttr.size();

                List<String> groups = new LinkedList<String>();

                for(int i=0;i<numberOfRoles;i++){

                  String ldapGroupLongName = (String) groupsAttr.get(i);

                  String databaseGroupName = translateLDAPGroupNameToDbGroupName(ldapGroupLongName);

                    groups.add(databaseGroupName);

                }

                userNameRolesMap.put(username,groups);

            }

        } catch (NamingException e) {

            e.printStackTrace();

            throw e;

        }

    }