@Startup
@Singleton
public class JdapHelper {

    private LdapContext ctx;
    String rootSearchBase="DC=dc,DC=local";
     
    @PostConstruct
    public void init() 
    {
       System.out.println(" class JdapHelper JdapHelper init()");
       
       String searchUserName="name";
        Hashtable env = new Hashtable();
        String adminName = "mail;
        String adminPassword = "pass";      

        String ldapURL = "ldap://url"; 
        env.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.ldap.LdapCtxFactory");
        env.put(Context.SECURITY_AUTHENTICATION, "simple");
        env.put(Context.SECURITY_PRINCIPAL, adminName);
        env.put(Context.SECURITY_CREDENTIALS, adminPassword);
        env.put(Context.PROVIDER_URL, ldapURL);
        env.put(Context.REFERRAL, "follow");
        
        try {
            //Создаем по заданным параметрам ldap context
            ctx = new InitialLdapContext(env, null);
        } catch (NamingException ex) {
           System.out.println(ex.fillInStackTrace());
            //Logger.getLogger(LdapHelper.class.getName()).log(Level.SEVERE, null, ex);
        }
    }