[BUG] TemplateProcessingException: T(de.otto.edison.util.DateTimeUtil).parse(dateTime)

[ConstanzeMaass2610]

Version: 4.0.6

requesting /status causes internal-ServerError

Error:

Whitelabel Error Page
This application has no explicit mapping for /error, so you are seeing this as a fallback.

Tue May 12 15:26:32 CEST 2026
There was an unexpected error (type=Internal Server Error, status=500).
An error happened during template parsing (template: "class path resource [templates/status.html]")

Caused by: org.thymeleaf.exceptions.TemplateProcessingException: Exception evaluating SpringEL expression: "T(de.otto.edison.util.DateTimeUtil).parse(dateTime)" (template: "fragments/widgets/date-time-badge" - line 7, col 6)

[ConstanzeMaass2610]

🤖copilot suggested this:

The root cause is clear: Spring Boot 4 / Spring Framework 7 has restricted SpEL's T() operator in Thymeleaf templates for security reasons. The template is calling T(de.otto.edison.util.DateTimeUtil).parse(dateTime) which invokes a static method.

The fix should be to avoid the T() operator in the template. The cleanest approach is to:

1. Pre-parse the date-time in the controller/model before it reaches the template, OR
2. Use a Thymeleaf utility bean instead of the T() operator

The values passed to the template are:

• system.systemTime
• system.systemStartTime
• vcs.commitTime

These are all strings that need parsing. I should check the domain objects and controller to see if I can convert these to OffsetDateTime types before they reach the template, which would be the cleanest solution.

🤷‍♀️ Me:
I will investigate this later. I don't understand what's the problem, but I am curious to figure it out. 👍