openapi-generator [Java] Fix content for enum in MultiPart (#19973)

Fix content for enum in addPartToMultiPartBuilder.

Enum is going forward set to MediaType text/plain and not MediaType application/json in MultiPartBuilder and .toString() is used to get the value from the enum.

Jun 04 '25 06:06 jarryDk

please follow step 3 to update samples so that CI can verify the change

Jun 04 '25 06:06 wing328

can you please review the CI failure when you've time?

Jun 10 '25 12:06 wing328

Had a look at ./CI/circle_parallel.sh as I can see it fails on samples/client/others/java/okhttp-gson-streaming - I do not bring any changes to samples/client/others/java/okhttp-gson-streaming.

For now my PR only update java/restclient and samples/client/others/java/okhttp-gson-streaming pass on my machine both with JDK8, JDK11 and JDK17

Jun 11 '25 06:06 jarryDk

do you need help updating the samples to fix https://github.com/OpenAPITools/openapi-generator/actions/runs/15577774453/job/44161740116?pr=21373 ?

Jun 16 '25 10:06 wing328

@wing328 - It should be ok now.

I have update the samples with

 bash bin/generate-samples.sh

where i previous used

./bin/generate-samples.sh ./bin/configs/*.yaml

Jun 17 '25 05:06 jarryDk