Sample Application Architecture

For the hands-on workshop labs you will be provided a complete spring mvc web server application together with a corresponding spring mvc thymeleaf web client app.

Table of Contents

• Application Component View

• Technology Stack

• Server Architecture

  • REST Api

  • Server Layers

  • Users and Roles

  • Provided application

• Client Architecture

  • Client Layers

  • Users and Roles

  • Provided application

Application Components

Workshop Architecture

The server application provides a RESTful service for administering books and users (a very lightweight books library).

Use cases of this application are:

• Administer books (Creating/editing/deleting books)

• List available books

• Borrow a book

• Return a borrowed book

• Administer library users

Tech Stack

The demo client and server application both are build using the Java programming language and utilizing the Spring Framework.

The following figure shows a typical Microservice technology stack implemented by various Spring projects.

Workshop Tech Stack

Server Architecture

The RESTful service for books and users is build using the Spring MVC annotation model and Spring HATEOAS.

The application also contains a complete documentation for the RESTful API that is automatically generated with spring rest docs. You can find this in the directory 'build/asciidoc/html5' after performing a full gradle build or online here: REST API documentation.

The server application is already secured by basic authentication and also includes authorization using static roles.

Server Layers

The domain model of the server application is quite simple and just consists of Book and User models. The packages of the application are organized according to the different application layers:

• api: Contains the complete RESTful service

• business: The service classes (quite simple for workshop, usually these contain the business logic)

• dataaccess: All domain models and repositories

In addition there more packages with supporting functions:

• common: Classes that are reused in multiple other packages

• config: All spring configuration classes

• security: All security relevant classes, e.g. a UserDetailsService implementation

REST API

To call the provided REST API you can use curl or httpie. For details on how to call the REST API please consult the REST API documentation which also provides sample requests for curl and httpie.

Server Users and roles

There are three target user roles for this application:

• LIBRARY_USER: Standard library user who can list, borrow and return his currently borrowed books

• LIBRARY_CURATOR: A curator user who can add, edit or delete books

• LIBRARY_ADMIN: An administrator user who can list, add or remove users

Important: We will use the following users in all subsequent labs from now on:

Username	Email	Password	Role
bwayne	[e-mail]	wayne	LIBRARY_USER
bbanner	[e-mail]	banner	LIBRARY_USER
pparker	[e-mail]	parker	LIBRARY_CURATOR
ckent	[e-mail]	kent	LIBRARY_ADMIN

These users are configured for basic authentication and also later for authenticating using keycloak.

Provided Server application

You can find the provided initial server application beneath the lab 1 folder as library-server-initial.

Client Architecture

The client is able to fulfill most of the provided uses cases by the server application like:

• View all available books in a list

• Borrow available books

• Return my borrowed books

• Create new books

All action buttons are visible depending on user authorizations, e.g. only users with LIBRARY_USER role can see the Borrow and Return buttons. The Return

Library Client

Client Layers

The domain model of the client application is quite simple and just consists of Book and User models. The packages of the application are organized according to the different application layers:

• web: Contains the complete spring web mvc layer with all required client side resources

In addition there is one more package with supporting functions:

• config: All spring configuration classes

In resources/templates you find all thymeleaf html templates. These templates use the bootstrap framework that resides in resources/static folder.

Client Users and Roles

There are three target user roles for this client application:

• LIBRARY_USER: Standard library user who can list, borrow and return his currently borrowed books

• LIBRARY_CURATOR: A curator user who can add, edit or delete books

• LIBRARY_ADMIN: An administrator user who can list, add or remove users

Username	Email	Password	Role
bwayne	[e-mail]	wayne	LIBRARY_USER
bbanner	[e-mail]	banner	LIBRARY_USER
pparker	[e-mail]	parker	LIBRARY_CURATOR
ckent	[e-mail]	kent	LIBRARY_ADMIN

Provided Client application

You can find the provided initial client application beneath the lab 2 folder as library-client-initial.