Log being spammed with messages: struts2.dispatcher.mapper.DefaultActionMapper

Problem

When using Confluence 8.1 we see log spam when accessing pages with some special characters in their names like "space" or "!"

Steps to Reproduce

1. Install Confluence 8.1
2. Create a page with space in its name like "test page with space"
3. Publish it .
4. Access this page.

Expected Results

No error or warning message

Actual Results

We can see these lines spamming in the atlassian-confluence.log every time a user accesses a page with spaces or some characters in it's name.

 2023-02-24 15:28:26,489 WARN [http-nio-8090-exec-9] [struts2.dispatcher.mapper.DefaultActionMapper] cleanupActionName teste+page+with+space did not match allowed action names [a-zA-Z0-9._!/\\-]* - default action index will be used!
- url: /display/TES/teste+page+with+space | userName: admin | referer: http://localhost:8090/collector/pages.action?key=TES | traceId: 342ca8bcdb871383
2023-02-24 16:09:06,061 WARN [http-nio-8090-exec-3] [struts2.dispatcher.mapper.DefaultActionMapper] cleanupActionName testing%21with%21exclamation did not match allowed action names [a-zA-Z0-9._!/\\-]* - default action index will be used!
- url: /display/TES/testing%21with%21exclamation | userName: admin | referer: 

Workaround

• To avoid restarting Confluence and to pick up the change, Go to     > General Configuration > Logging and Profiling.
• Add New Entry

  Class/Package Name	org.apache.struts2.dispatcher.mapper.DefaultActionMapper
  New Level	ERROR

• You can also choose to add this to your <confluence_install>/confluence/WEB-INF/classes/log4j.properies file that will be picked during startup :

  log4j.logger.org.apache.struts2.dispatcher.mapper.DefaultActionMapper = ERROR
  

  Notes