It’s as easy as implementing a listener and calling another activity:
Journey will be done as defined by IEOS Customer Journey configuration.

• Implement or create an instance of CustomerJourneyEventReceiver implementation.

private CustomerJourneyEventReceiver implementation = new CustomerJourneyEventReceiver() {
	@Override
	public void onJourneyCompleted(Context context, ResponseJourney responseJourney) {
	// Results from Customer Journey
	}
	@Override
	public void onJourneyFailed(Context context, CustomerJourneyError errorCode) {
	// Failed check error object for more information. At the end see possible errorCodes.
	}
	@Override
	public void onJourneyCanceled(Context context, CustomerJourneyError error) {
	// If journey was cancelled, onBack() click event.
	}
};

Kotlin

// Callback interface of Customer journey
private val response: CustomerJourneyEventReceiver = object : CustomerJourneyEventReceiver() {
	/* Called back if customer clicked back or exits Customer Journey. */
	override fun onJourneyCanceled(context: Context, customerJourneyError: CustomerJourneyError) {
	}
	/* Callback if journey was successfully completed. */
	override fun onJourneyCompleted(context: Context, responseJourney: ResponseJourney) {
	}
	/* Callback for failure from witch we dit not succeed to restore our self. */
	override fun onJourneyFailed(context: Context, customerJourneyError: CustomerJourneyError) {
	}
}

• Register your implementation using

Note: Kotlin register before and unregister after response, as register would create a new instance and not override the old.

// Register before call CustomerJourneyService.registerEventReceiver(context, implementation);

// Unregister after call CustomerJourneyService.unregisterEventReceiver(context, implementation);

• Create an intent with:
  1. EXTRA_BASE_LINK: Add server base URL if POC server provided by GBG IDscan its most likely https://company.idscan.cloud
  2. CREDENTIALS: Add Scanning Area credentials
  3. Intent to CustomerJourneyActivity and start it.

// Create intent to start scanner activity
Intent customerJourney = new Intent(this, CustomerJourneyActivity.class);
customerJourney.putExtra(CustomerJourneyActivity.EXTRA_BASE_LINK, baseUrl);
customerJourney.putExtra(CustomerJourneyActivity.EXTRA_CREDENTIALS, new Credentials(username, password));
startActivity(customerJourney);

Note: Don’t forget to add a check for camera permissions.

Possible onJourneyFailed(CustomerJourneyError) codes:

Code	Description
EnterpriseService EXCEPTION_ERROR 500	Returns when Web service experienced unrecoverable situation and returns localised exception message.
408	Internal server error, more information on server side. Server time out
401	Unauthorised, possibly bad credentials.
400	Bad Request
…	Other error HTTP status codes possible https://en.wikipedia.org/wiki/List_of_HTTP_status_codes
CustomerJourneyError	Errors from customer journey itself
NONE	No error
GENERAL	General error check message
NO_SERVER_RESPONSE	Journey Failed server din’t respond
UNKNOWN_REQUIRED_ACTION	Journey Failed because of unknown action
CAMERA	Journey Failed because of camera failure
WEB_INITIALIZING	Creating webservice instance failed
WEB_INITIALIZING_BAD_URL	Creating Retrofit instance failed with IllegalArgumentException
EXECUTION	Execution error, most likely exceptions from witch we are not recovering, will send exception localised message.

For more information check JavaDocs on possible call exceptions.