Spring MVC public logo image sample

This sample demonstrates how to create publicly available Spring MVC controller in the web module of the CUBA project.

• MVC controller serves clients with publicly available logo images stored in the database.
• Logo images can be uploaded in the web client (Side Menu -> Application -> Logo Images).
• Controller URL: http://localhost:8080/app/dispatch/logo/{FILE_NAME}, e.g. http://localhost:8080/app/dispatch/logo/cuba_studio.png
• Images are requested without any authentication
• Data is loaded under the anonymous user session using this user's permissions
• Implementation does not depend on the REST API addon

Important code points

1. Data Model

• com.sample.logos.entity.LogoImage - JPA entity storing logo images (as byte array).

• logo-image-browse.xml - Logo image browser & editor screen.

2. Spring MVC

• com/sample/logos/web-dispatcher-spring.xml - add package for component scan where our MVC controllers will be located:

<context:component-scan base-package="com.sample.logos.web.controller"/>

• com.sample.logos.web.controller.LogoController - implementation of the Spring MVC controller.

• com.sample.logos.web.controller.LogoController#withAnonymousUserSession(Callable) - method to execute code block with permissions of the anonymous user.

• web/WEB-INF/web.xml - this is where /dispatch/ part of the URL comes from.

3. Security settings

• com.sample.logos.core.role.LogoReaderRole - design-time role definition with permission to read LogoImage entities.

• db/init/hsql/30.create-db.sql - contains SQL statement to automatically assign LogoReader role to the anonymous user during database creation:

insert into SEC_USER_ROLE (ID, VERSION, USER_ID, ROLE_NAME)
values (newid(), 1, (select ID from SEC_USER where LOGIN = 'anonymous'), 'LogoReader');

Screenshots