InterceptingIdentityStore.java

public User getUser(String uniqueUserId) throws IdentityStoreException, UserNotFoundException {

        //Pre handler
        Map<String, Object> eventProperties = new HashMap<>();
        eventProperties.put(IdentityStoreConstants.UNIQUE_USED_ID, uniqueUserId);

        Event event = new Event(IdentityStoreInterceptorConstants.PRE_GET_USER_BY_ID, eventProperties);
        IdentityMgtMessageContext messageContext = new IdentityMgtMessageContext(event);

        try {
            eventService.handleEvent(messageContext);
        } catch (EventException e) {

            String message = String.format("Error while handling %s event.", IdentityStoreInterceptorConstants
                    .PRE_GET_USER_BY_ID);
            throw new IdentityStoreException(message, e);
        }
        User user;
        try {
            user = identityStore.getUser(uniqueUserId);
        } catch (IdentityStoreException e) {

            String message = String.format("Error during rollback operation of %s event", IdentityStoreInterceptorConstants
                    .PRE_GET_USER_BY_ID);
            try {

                eventService.rollbackEvent(messageContext);
                
            } catch (EventException e1) {
                IdentityStoreException ex = new IdentityStoreException(message, e1);
                e.addSuppressed(ex);
            }
            throw e;
        }
        //Post handler
        eventProperties = new HashMap<>();
        eventProperties.put(IdentityStoreConstants.UNIQUE_USED_ID, uniqueUserId);
        eventProperties.put(IdentityStoreConstants.USER, user);

        event = new Event(IdentityStoreInterceptorConstants.POST_GET_USER_BY_ID, eventProperties);
        messageContext.setEvent(event);

        try {
            eventService.handleEvent(messageContext);
        } catch (EventException e) {

            String message = String.format("Error while handling %s event.", IdentityStoreInterceptorConstants
                    .POST_GET_USER_BY_ID);

            try {

                eventService.rollbackEvent(messageContext);

            } catch (EventException e1) {
                IdentityStoreException ex = new IdentityStoreException(message, e1);
                e.addSuppressed(ex);
            }
            throw new IdentityStoreException(message, e);
        }

        return user;
    }