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https://issues.apache.org/jira/browse/WW-5690?focusedWorklogId=1037401&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-1037401
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ASF GitHub Bot logged work on WW-5690:
--------------------------------------
Author: ASF GitHub Bot
Created on: 24/Aug/26 09:56
Start Date: 24/Aug/26 09:56
Worklog Time Spent: 10m
Work Description: lukaszlenart opened a new pull request, #1864:
URL: https://github.com/apache/struts/pull/1864
Fixes [WW-5690](https://issues.apache.org/jira/browse/WW-5690)
`DefaultDispatcherErrorHandler.init()` built a FreeMarker configuration and
loaded `/org/apache/struts2/dispatcher/error.ftl` on **every** startup —
including production, where the problem report is never rendered.
`handleError()` only reaches it when devMode is on; otherwise it delegates to
the container's error page.
So every Struts application today pays to initialise FreeMarker for a page
most of them never show.
## Change
`init()` now just stores the `ServletContext`. A new `protected
getTemplate()` loads the template on first use and caches it in a `volatile`
field.
No lock: two threads racing on the very first error may both load it, which
is harmless — FreeMarker caches templates in its own `Configuration` — and
cheaper than locking a path taken once per application lifetime.
## One behavioural change
A missing or unparsable `error.ftl` used to throw `StrutsException` from
`init()` and fail the application at boot. It now surfaces on the first
dev-mode error, where the existing `catch (Exception exp)` in
`handleErrorInDevMode()` already degrades to `sendError(code, "Unable to show
problem report: ...")`.
I'd argue that's an improvement — a dev-only template shouldn't stop a
production application starting — but it is a change in failure timing and
worth a reviewer's eye.
## Scope
Startup cost only. The `FreemarkerManager` injection, the
`freemarker.template.Template` import and `error.ftl` itself all stay. Removing
core's FreeMarker dependency outright is the remaining half of WW-5690, and
part of the lean-core work tracked in
[WW-5689](https://issues.apache.org/jira/browse/WW-5689) alongside
[WW-5691](https://issues.apache.org/jira/browse/WW-5691) and
[WW-5692](https://issues.apache.org/jira/browse/WW-5692).
## Tests
Two added to `DefaultDispatcherErrorHandlerTest`, using a
`FreemarkerManager` subclass that records whether `getConfiguration` was called
(no mocking framework needed — it delegates to `super`, so the template really
renders):
- `testInitDoesNotLoadErrorTemplate` — asserts `init()` leaves FreeMarker
untouched. **Verified failing before the change**, on the assertion, which is
what makes it a real regression guard.
- `testErrorTemplateLoadedOnFirstDevModeError` — asserts the deferred load
actually happens, so the report can't silently stop rendering.
The four existing tests are unchanged and still pass. Full `core` suite:
3197 tests, 0 failures, 0 errors.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Issue Time Tracking
-------------------
Worklog Id: (was: 1037401)
Remaining Estimate: 0h
Time Spent: 10m
> Remove core's FreeMarker dependency from DefaultDispatcherErrorHandler
> ----------------------------------------------------------------------
>
> Key: WW-5690
> URL: https://issues.apache.org/jira/browse/WW-5690
> Project: Struts 2
> Issue Type: Task
> Components: Core
> Reporter: Lukasz Lenart
> Assignee: Lukasz Lenart
> Priority: Major
> Fix For: 7.4.0
>
> Time Spent: 10m
> Remaining Estimate: 0h
>
> Part of the WW-5689 lean-core work, but self-contained and shippable in 7.x.
> *Scope note.* This is about _core's own_ dependency on FreeMarker.
> Applications using the Struts tag library still require FreeMarker
> regardless: {{struts.ui.templateSuffix}} defaults to {{ftl}} and all 129
> bundled theme templates are {{.ftl}}. What these tickets buy is that a
> REST/JSON-only application — one that never renders a tag — stops paying for
> FreeMarker.
> h2. Current behaviour
> {{DefaultDispatcherErrorHandler}} renders the dev-mode error report through
> FreeMarker:
> * it holds an injected {{FreemarkerManager}}
> * {{init(ServletContext)}} calls {{freemarkerManager.getConfiguration(ctx)}}
> and loads {{/org/apache/struts2/dispatcher/error.ftl}}
> * only {{handleErrorInDevMode(...)}} ever uses the resulting template
> {{init()}} is *unconditional*. It runs at dispatcher startup and initialises
> the whole FreeMarker configuration even in production mode, where the
> template is never rendered — {{handleError(...)}} goes to
> {{sendErrorResponse(...)}} and delegates to the container's error page.
> h2. Proposal
> Render the dev-mode error report without FreeMarker — a plain Java renderer
> is sufficient for what {{error.ftl}} produces.
> Failing that, the minimum acceptable change is to make the template load lazy
> and gate it on devMode, so a production deployment never touches FreeMarker
> through this path.
> {{DispatcherErrorHandler}} is already a pluggable bean, so a FreeMarker-based
> handler can remain available for anyone who has customised {{error.ftl}}.
> h2. Compatibility
> {{error.ftl}} is an internal template, not a documented extension point. If
> the plain renderer lands, note the change in the migration guide for anyone
> who has overridden it.
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