Grails 7: Controller hotswap change doesn't take effect.

[arjangch]

Expected Behavior

In grails 5, I can hot change actions in controllers. It will show the result of my changes after auto re-compile.

Actual Behaviour

Grails 7 auto re-compiles but still runs old code.
There won't be any changes until I stop Grails 7 and start it again.

Steps To Reproduce

1. Go to https://start.grails.org/ and download Grails 7 M1 project
2. cd inside directory
3. ./gradlew bootRun
4. Stop the app
5. ./grailsw create-domain-class com.example.Student
6. ./grailsw generate-all com.example.Student
7. ./gradlew bootRun
8. Stop the app again
9. Edit grails-app/controllers/com/example/StudentController.groovy
10. add this line to index action println '======grails 7====print 1========'
11. in browser go to http://localhost:8080/student/index and click on com.example.StudentController
12. You will see this in console ======grails 7====print 1========
13. Do not stop the app. Edit grails-app/controllers/com/example/StudentController.groovy and change print to println '======grails 7====print 2========'`
14. After auto recompile, go to http://localhost:8080/student/index and click on com.example.StudentController
15. You will see ex in console ======grails 7====print 1========

Expected

Expected to see ======grails 7====print 2========

Actual

But actually is printed is ======grails 7====print 1========

Environment Information

• Mac OS
• java=22.0.2-zulu
  gradle=8.10
  groovy=4.0.22

Example Application

No response

Version

grails=7.0.0-SNAPSHOT

[jdaugherty]

https://github.com/grails/grails-gradle-plugin/blob/6.2.x/src/main/groovy/org/grails/gradle/plugin/watch/GrailsWatchPlugin.groovy was removed in Grails 7.x. I believe the intent is to switch to a reloading agent in Grails 7.x instead of just restarting the context.

Reloading has been shown to work (proof of concept is here https://youtu.be/Fz_sKuZ-ytg). We intend to make this less painful to setup before the official release of Grails 7.

[Taack]

This issue seems to also apply to Grails 6.2.3 (and may be to 6.2.2). I cannot start my app using interactive Grails command as stated in Using Interactive Mode. I do use ./gradlew bootRun -Dgrails.run.active=true command to launch the app, and prior Grails versions (6.2.1) hot restart takes effect in case of controller / service change.

The file layout of our app is particular, we use buildSrc approach to build the app, and the app is splitted into Grails plugin. See Modular Directory Layout.

If you think my issue is unrelated, I can open another bug report.

Thanks for your support.

It is working, I do have to remove the Confgirugation closure from previous version ..

configurations {
    developmentOnly
    runtimeClasspath {
        extendsFrom developmentOnly
    }
}

[arjangch]

I changed steps above and tested it again in Grails 5 and Grails 7 with different results.
After editing controller and changing println in Controller

Expected Grails5

Print in console ======grails 5====print 2========

Actual Grails5

Print in console ======grails 5====print 2========

Expected Grails7

Print in console ======grails 5====print 2========

Actual Grails7

Print in console ======grails 5====print 1========

Conclusion

Grails7 compiles controller but it does not take effect.

P.S. I do not change any config file or properties.

[davydotcom]

your missing some steps. you gotta use a specific jdk and configure the hotplug jar

[davydotcom]

we will provide a guide on it

[jeffscottbrown]

you gotta use a specific jdk

Which JDK will work?

[davydotcom]

Instructions for using hotswap agent are mostly here: https://hotswapagent.org/

you also need a groovy jar for this to run (which we are working on packaging up ).

The JetBrains JDK seems to be the best choice and works with the instructions on that website

[jamesfredley]

The most recent working examples with hotswap agent: https://github.com/grails/grails-forge/issues/445

[jamesfredley]

We may need to revisit apache/grails-gradle-plugin@755b810 or other similar changes since the hotswap agent is no longer working as it did on https://www.youtube.com/watch?v=Fz_sKuZ-ytg using https://github.com/codeconsole/website/tree/7.0.0-SNAPSHOT

Same for examples using the latest Grails 7 snapshot:

https://github.com/jamesfredley/hotswap-demo
https://github.com/jamesfredley/hotswap-demo/tree/latest-hotswap-agent - branch using locally built, latest hotswap-agent.jar, since snapshots are not published

Also @arjangch I think the original issue you submitted is solved by selecting the SpringBoot Developer Tools feature on start.grails.org. That was a default feature in Grails 5. But this ticket is now focused on hotswap agent.