Boot Dashboard build cannot locate files

[navy1978]

Hi,
We encountered a perplexing issue while utilizing STS 4.21.0.
Although the system generally (99% of the time) functions smoothly, we intermittently encounter an error when attempting to start a microservice from the Boot Dashboard. The error message is as follows:

Field mapper in xxx.yy.MyService required a bean of type 'xxx.yy.MyMapper' that could not be found.

Our project employs mapstruct, and the necessary Mapper is generated and located within the directory:
target/generated-sources/annotations.

Interestingly, manually editing the file that cannot be found within STS resolves the issue temporarily, but the application subsequently fails to locate another required file.

Our suspicion is that the build process triggered when starting the microservice from the Dashboard becomes corrupted, resulting in an inability to locate these files.

Once this error occurs it doesn't go away (recompiling refreshing , maven update, restart of STS, whatever doesnt work), but strangely, executing the following command via the command line:

mvn spring-boot:run

Allows the microservice to start successfully. Upon stopping the service and returning to STS, starting the microservice from the Dashboard works flawlessly. It appears that executing the command via the command line initiates a process that somehow rectifies the issue.

It's worth noting that occasionally, instead of the previously mentioned error, we encounter the following:

Caused by: java.lang.IllegalArgumentException: Could not resolve placeholder 'my.uri' in value "${my.uri}"
	at org.springframework.util.PropertyPlaceholderHelper.parseStringValue(PropertyPlaceholderHelper.java:180) ~[spring-core-6.0.15.jar:6.0.15]
	at org.springframework.util.PropertyPlaceholderHelper.replacePlaceholders(PropertyPlaceholderHelper.java:126) ~[spring-core-6.0.15.jar:6.0.15]

This error suggests an inability to locate the application.properties file. Again it looks like the build cannot locate some files

Please be aware that this issue began occurring with the 4.21.0 version of STS, as we had no such problems with version 4.15.0.

Unfortunately I cannot provide the steps to reproduce this.
I hope what I described makes sense to you.

Thank you so much for your work!

[BoykoAlex]

It smells a lot like then m2e issue consequences in Eclipse: #929.
Do you mind giving m2e latest snapshot a try? (M2E snapshot update site: https://download.eclipse.org/technology/m2e/snapshots/latest/) Might solve your issue.
Also Cleaning the project and building from scratch ideally should help as well.

[navy1978]

Thanks! Just installed I will keep you updated.

(FYI : till now Cleaning the project and building from scratch didn't help)

[martinlippert]

Thanks! Just installed I will keep you updated.

That is awesome, thanks for giving this a try. Would be extremely interesting to know whether this new m2e snapshot version solves this issue for you. Please keep us updated on that.

[navy1978]

Unfortunatlty it didn't work.

FYI:

1. lanching the app from the Boot Dashborad produces again this error:
   _***************************
   APPLICATION FAILED TO START

---

Description:
Field mapper in xxxx.yyy.MyService required a bean of type 'xxxx.yyy.MyMapper' that could not be found.
Action:
Consider defining a bean of type 'xxxx.yyy.MyMapper' in your configuration._

2. if I create a "maven build" in Eclipse/STS and I put:
   goals: spring-boot:run

this works fine, and it was working well even before having updated m2e to the latest snapshot.

This issue is a little bit frustrating because it doesnt occur all the time and it's complicated to provide the steps to reproduce it.
Do you have other suggestions?

[martinlippert]

Hmmm... 🤔 If you startup the application via the dashboard and the error message appears, could you take a look at the target output folder and its content to see if there is anything missing from it? Maybe some files missing in that folder that you would expect to be there? (like application.prpoerties, .class files for the mapstruct generated sources, etc.) That might point us in some direction.

[navy1978]

The files are all there, but somehow STS/Eclipse cannot find them.
FYI: once I got this error I have modified the created, modified and accessed date of all files in the target folder with a little software, this somehow made STS/Eclipse locate the files again and the app started form Boot Dashboard with no issue. I cannot guarantee this was not a coincidence . I will keep you updated.

[navy1978]

Just a little update on this, I can confirm that using this little app: https://www.petges.lu/download/
and changing the created, modified and accessed date of all files in the target folder seems a workaround for this issue.
At least it solved it 3 times in a row.

Anyway whould be nice to understand the cause ...

[martinlippert]

Just a little update on this, I can confirm that using this little app: https://www.petges.lu/download/ and changing the created, modified and accessed date of all files in the target folder seems a workaround for this issue. At least it solved it 3 times in a row.

This is quite puzzling. If I understand you correctly, you are changing the modification timestamp of the files with the tool you mentioned and then it works?

Another test here could be to run the application from the command line instead of the boot dashboard to see if just running java with the classpath and main class specified works fine or not (without modifying those file attributes upfront).