public SimpleCredentialStoreImpl(Map<String, String> credentials,
    Collection<ConfigurationEntryFactory> realms,
    ClassLoader cl) 
{
        if (realms != null) {
            configuration = new GeronimoLoginConfiguration(realms, true);
        } else {
            configuration = null;
        }
        if (credentials != null) {
            for (Map.Entry< String, Map< String, Map< String, String > > > realmData: credentials.entrySet()) {
                String realmName = realmData.getKey();
                Map< String, Map< String, SingleCallbackHandler > > realm = getRealm(realmName);
                for  (Map.Entry< String, Map< String, String > > subjectData: realmData.getValue().entrySet()) {
                    String subjectId = subjectData.getKey();
                    Map< String, SingleCallbackHandler > subject = getSubject(realm, subjectId);
                    for (Map.Entry< String, String > credentialData: subjectData.getValue().entrySet()) {
                        String handlerType = credentialData.getKey();
                        String value = credentialData.getValue();
                        try {
                            Class< ? extends SingleCallbackHandler > clazz = (Class< ? extends SingleCallbackHandler >) cl.loadClass(handlerType);
                            Constructor< ? extends SingleCallbackHandler > c = clazz.getConstructor(String.class);
                            SingleCallbackHandler handler = c.newInstance(value);
                            String callbackType = handler.getCallbackType();
                            subject.put(callbackType, handler);
                        } catch (Exception e) {
                            throw new IllegalArgumentException("Could not construct SingleCallbackHandler of type: " + handlerType + " and value: " + value + " for subjectId: " + subjectId + " and realm: " + realmName, e);
                        }
                    }
                }
            }
        }
}

 public  void addEntry(String realm,
    String id,
    Map<String, SingleCallbackHandler> callbackInfos) 
{
        Map< String, Map< String, SingleCallbackHandler > > idMap = getRealm(realm);
        idMap.put(id, callbackInfos);
}

 public Subject getSubject(String realm,
    String id) throws LoginException 
{
        Map< String, Map< String, SingleCallbackHandler > > idMap = credentialStore.get(realm);
        if (idMap == null) {
            throw new LoginException("Unknown realm: " + realm);
        }
        final Map< String, SingleCallbackHandler > callbackInfos = idMap.get(id);
        if (callbackInfos == null) {
            throw new LoginException("Unknown id: " + id + " in realm: " + realm);
        }
        LoginContext loginContext = ContextManager.login(realm, new CallbackHandler() {
            public void handle(Callback[] callbacks) throws UnsupportedCallbackException {
                for (Callback callback: callbacks) {
                    if (!callbackInfos.containsKey(callback.getClass().getName())) {
                        throw new UnsupportedCallbackException(callback);
                    }
                    SingleCallbackHandler singleCallbackHandler = callbackInfos.get(callback.getClass().getName());
                    singleCallbackHandler.handle(callback);
                }
            }
        },
                configuration);
        return loginContext.getSubject();
}