Create rules for dropped servlet-based integrations

[jmle]

According to the migration guide:

Several outdated Servlet-based integrations have been dropped: e.g. Apache Commons FileUpload (org.springframework.web.multipart.commons.CommonsMultipartResolver), and Apache Tiles as well as FreeMarker JSP support in the corresponding org.springframework.web.servlet.view subpackages. We recommend org.springframework.web.multipart.support.StandardServletMultipartResolver for multipart file uploads and regular FreeMarker template views if needed, and a general focus on REST-oriented web architectures.

Investigate and create rules if necessary.

In the rule description and message, try to be as verbose and clear as possible. Code examples are always welcome and useful. Feel free to use markdown syntax for these.

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[jmle]

Dropping Apache Tiles/Freemarker JSP would mean a migration in its own right. Some additional info:

In Spring 6, the focus has shifted towards:

StandardServletMultipartResolver: This is recommended for handling file uploads without Apache Commons FileUpload.
Pure FreeMarker Templates: If using FreeMarker, it’s suggested to use standard FreeMarker templates without JSP, leveraging FreeMarker’s native features for server-side rendering.
REST-Oriented Architectures: For web applications, Spring encourages REST-based backends with client-side rendering frameworks (like React, Angular, or Vue.js) or modern templating approaches, such as Thymeleaf.

Example Migration Approaches

Migrating from Apache Tiles:
Thymeleaf: Use Thymeleaf’s layout dialect to replicate the modular view composition offered by Tiles.
Client-Side Rendering: For more complex UIs, REST APIs with client-side frameworks are often recommended.
Migrating from FreeMarker JSP:
Standard FreeMarker Views: Use FreeMarker without JSP tags. Configure it with FreeMarkerConfigurer and FreeMarkerViewResolver.
Thymeleaf: If starting fresh, consider Thymeleaf as a flexible alternative to FreeMarker with rich templating features.