Introduction

This is simple chat web application named Chatty.

Online demo

Demo version is deployed on Heroku and available under link: https://tranquil-retreat-49438.herokuapp.com/

Architecture

Chatty uses STOMP over WebSocket protocol for chat messages processing. I have choosen STOP protocol because it is supported out of the box by Spring Framework used as base framework. For more sophisticated use cases it would be worth to consider XMPP protocol but due to limited time and budget it was much easier to use STOMP.

Chatty manages internally STOMP user subscriptions for proper messages routing.

There is simple REST API exposed for chats retrieval and creation.

Chatty uses RxJava for asynchronous processing. I have choosen this approach because asynchronous applications scale well.

Technologies

Back-end

• Java 8
• RxJava
• Spring Boot
• Spring Security
• Spring Messaging
• Spring Data JPA
• Hibernate
• H2 Database
• Jolokia
• Slf4J/Logback
• Spring Actuator
• Spring Test
• JUnit
• Mockito
• Lombok

Front-end

• AngularJS 1.6
• Restangular
• Angular UI Router
• Sock.JS
• Stomp.JS
• Twitter Bootstrap 3

Tools

• Maven 3
• Jacoco

Manageability

Chatty exposes standard Spring Boot Actuator management endpoint. Additionaly chatty exposes some JMX endpoints for monitoring and management. There is also JMX-HTTP bridge available via Jolokia under /jolokia path. To access any management HTTP endpint you need to sign-in as admin user.

Configuration

Standard configuration properties are stored in src/main/resources/application.yml file. Configuration properties can be overriden by command line arguments or environment variables.

Notes on building, testing and runing

You need maven 3 and Java 8 JDK installed to build Chatty or run tests.

Building

To build Chatty just enter main project folder and run mvn clean install. This will build executable jar target/chatty-[version].jar.

Testing

To run all unit and integration tests run mvn clean verify in root project folder. All test will be exexuted and test coverage will be stored in target/site/jacoco folder. Open index.html file to see test coverage report generated by Jacoco.

Running

To run Chatty execute command java -jar chatty-[version].jar.

You can also run Chatty via spring-boot-maven-plugin. Enter project root folder and run mvn spring-boot:run

Chatty uses port number 8080 by default. In case of port conflicts just override port configuration property by adding command line option:

• --server.port=[port number] in case of running it via java
• -Dserver.port=[port number] on case of running it via maven