vaadin-javaee-clinic-patient-queue-example

An example clinic patient queue application using Vaadin 8, Java EE 8 and Vaadin CDI add-on.

Demonstrates how to use Vaadin's server push and Java EE messaging APIs to send messages to client browsers in real time. Uses JMS 2.0 API for sending messages, message-driven beans for receiving them and a separate singleton broadcaster to broadcast messages to Vaadin UIs (the broadcaster is recommended by Vaadin as a bridge for connecting message-driven beans and Vaadin UIs that have different lifetimes).

Also demonstrates how to authenticate and authorize users using JAAS and Vaadin login form and view navigator.

Vaadin's server push uses a WebSocket connection by default which unfortunately is not compatible with CDI, so for the time being a mixed communication mode with WebSocket for server to client and XMLHttpRequest for client to server must be used with @Push(transport = Transport.WEBSOCKET_XHR).

Tested with WildFly 18.0.1, but should work equally well with other Java EE 8 application servers.

The project consists of the following modules:

• parent project: common metadata and configuration
• vaadin-javaee-clinic-patient-queue-example-ui: main Vaadin application module
• vaadin-javaee-clinic-patient-queue-example-backend: backend module, contains server side code and dependencies.

Building and running

You need Maven and Java 8 JDK to build and run the application.

Build the application WAR with mvn package, deploy it from vaadin-javaee-clinic-patient-queue-example-ui/target/vaadin-javaee-clinic-patient-queue-example.war to the application server.

Note that you need to run WildFly with full profile to enable JMS:

bin/standalone.{bat,sh} -c standalone-full.xml

Overview

The project consists of three apps:

• Registration kiosk app where patients can register to doctor's appointments
• Doctor's office app for doctors to see when patients arrive and call them in
• Infoscreen where patients are notified when doctor calls them in.

If you have Google Chrome installed, you can launch all the apps in parallel with launch-apps.sh.

The following screencast shows the whole workflow in action:

Testing

1. Open doctor's office app in first browser window
2. Login as user with password user (see Adding doctors below), dr. Anu Võsu's office view opens
3. Open registration kiosk in second browser window
4. Enter your name and press Register under dr. Anu Võsu's name to register to her appointment
5. The kiosk will output your call-in number
6. Open infoscreen in third browser window
7. Switch to doctor's office app and observe that your registration is visible on the page
8. Select your registration and press Call in
9. Switch to infoscreen and observe that your call in number is visible in the list

A Vaadin TestBench test is also included, if you have a TestBench licence and Chrome WebDriver installed, you can run it with

mvn -Dtest=ClinicPatientQueueAppIT -DfailIfNoTests=false test

Prerequisite is that the application server is running the application in the background.

Adding doctors

WildFly has a security realm called ApplicationRealm configured by default.

To add a new user to ApplicationRealm execute the add-user.{bat,sh} script within the bin folder of your WildFly installation and enter the requested information. Choose b) Application user and add the user to the group users.

Add user user with password user for the test to work.

References

• Server Push chapter in official Vaadin documentation