Motivation:

• When a client sends a request with a JSON body but does not configure the content-type in header, Central Dogma returns the response: {"exception":"java.lang.IllegalArgumentException","message":"No suitable request converter found for a @RequestObject 'CommitMessageDto'"}. This response is quite ambiguous, making it difficult for the client to understand the problem.

Modifications:

• Add @ConsumesJson to each method that uses ChangesRequestConverter.class.

FYI

1. If @RequestConverter is declared on method signatures, Armeria will add an object Resolver. (link)
2. Then, when Armeria receives a request from client, Armeria will try to resolve the request. (link)
3. ChangesRequestConverter tries to parse body from request. Actually, ChangeRequestConverter delegates to JacksonRequestConvertFunction.
4. JacksonRequestConverter validates contents type. (here)
5. If there is no content-type or content-type is not application/json, JacksonRequestConverter will call RequestConverterFunction.fallthrough().

With this flow, client will receive response : {"exception":"java.lang.IllegalArgumentException","message":"No suitable request converter found for a @RequestObject 'CommitMessageDto'"}.

If @ConsumsJson is delcared to each method having ChangesRequestConverter.class on their method signature, Armeria will not try to resolve request without header Content-Type: application/json.

Result:

• Client will receive 415 response.

$ curl -X POST localhost:8080/my-post \
-d '{"name": "John Doe", "email": "[email protected]"}'
>>
Status: 415
Description: Unsupported Media Type

• Closes Add @Consume(content-type) to all REST services class or methods  #987.