Add tests for json-customize example

[fp024]

Summary

Adds JUnit tests for the json-customize example.

Motivation

This PR adds a reproducible JUnit test case to the struts-examples repository to make it easier to verify the behavior of the custom JSON writer configuration.

With Struts 7.1.1, the custom JSON writer configured by the json-customize example is used as expected. However, after changing only the Struts version to 7.2.1, the configured custom JSON writer no longer appears to be selected, and org.apache.struts2.json.StrutsJSONWriter is used instead.

The behavior can be reproduced or verified by changing only the Struts version to 7.2.1 and running the added tests.

Since the Struts main repository does not have the Issues tab enabled, I am submitting this to struts-examples as a reproducible test case.

Notes

The tests use "json-unit-assertj" to validate the serialized JSON output. The lastLogin field is validated by date format instead of comparing against a fixed value.

Thanks 👍

[lukaszlenart]

@fp024 you must rebase onto main branch

[fp024]

@lukaszlenart
Rebased onto the latest main branch. Thank you.

[fp024]

When flexjson excludes fields with null values, it leaves trailing keys behind, which results in an invalid JSON string. I have pushed an additional commit to resolve this issue.

[lukaszlenart]

Test ProduceActionTest fails

[fp024]

I added and shared this test case specifically because it fails on Struts 7.2.1 while passing completely on Struts 7.1.1.

On Struts 7.2.1, the following configuration does not take effect, and the system is seemingly forced to use only the default StrutsJSONWriter instead of our custom bean:

  <bean type="org.apache.struts2.json.JSONWriter" name="flexJSONWriter" class="org.demo.FlexJSONWriter"
        scope="prototype"/>
  <constant name="struts.json.writer" value="flexJSONWriter"/>

[lukaszlenart]

Thanks for that, I will double check what's wrong

[lukaszlenart]

Nice, this is regression in Struts 7.2.1, I will prepare a fix.

[lukaszlenart]

Ticket ready, on it
https://issues.apache.org/jira/browse/WW-5641

[fp024]

Thank you very much for checking. Have a nice day! 👍

[lukaszlenart]

Thanks for this — the ProduceActionTest coverage and the ProduceAction cleanup are welcome, and this module had no tests at all before.

Heads up that #544 just landed and overlaps part of this PR, which is why it now shows conflicts. On current main, json-customize already has:

• web.xml migrated to the Jakarta EE 6.0 schema (same target as your change)
• struts.xml on https://struts.apache.org/dtds/struts-6.5.dtd
• the POM schema URL moved to https://

So when you rebase, the XML parts of this PR can simply be dropped. Two of them would otherwise move things backwards:

• your struts.xml points at http://struts.apache.org/dtds/struts-6.0.dtd, where main is now on https:// and 6.5
• your web.xml keeps id="struts_blank"/id="WebApp_ID", which the migration dropped repo-wide

The valuable parts — ProduceActionTest.java, and the changes to ProduceAction, ExcludeTransformer, and FlexJSONWriter — rebase cleanly as far as I can tell.

One thing to check while you're rebasing: struts.parameters.requireAnnotations has defaulted to true since before 7.2.1, so any action property that receives a request parameter needs @StrutsParameter (depth 0 on the setter, depth ≥ 1 on the getter). #544 fixed seven modules that were silently dropping parameters. If ProduceAction takes any request input, it likely needs the annotation too — and a test that posts a parameter and asserts it arrives would catch exactly that class of bug.

CI is also currently red here (build (21) failed, build (17) cancelled) from before the conflicts, so worth a look after the rebase.

[fp024]

@lukaszlenart

Hi, thanks for the review!

I've rebased the branch on main and dropped the redundant XML/DTD changes as suggested.
I verified locally that mvn clean test passes cleanly.

Regarding @StrutsParameter: ProduceAction only outputs internally generated data as JSON and doesn't accept any incoming request parameters, so no additional annotations were needed.

Thanks!

[fp024]

Update: Added a follow-up commit as the assertion update to json-unit-assert was missing after the rebase.

[fp024]

Hello.

The struts-6.5.dtd file has not been uploaded to https://struts.apache.org/dtds/.

• https://struts.apache.org/dtds/struts-6.5.dtd

In the case of IntelliJ, there were no issues as it automatically reads the struts-6.5.dtd embedded in struts2-core-7.3.0.jar...

However, in the VS Code + Red Hat XML Extension environment, a 404 error occurs because it attempts to download the DTD directly from the web at that address and cache it.

https://struts.apache.org/dtds/struts-6.0.dtd is currently available for download.

It seems that the struts-6.5.dtd file also needs to be uploaded.

Please check into this.

[lukaszlenart]

Good catch, I will fix that later, thanks!