Swagger documentation issue when using proto complied Pojo used in rest controller

[dockndev]

Use Case :
We are using gRPC in our microservices setup, where gRPC is utilized for internal communication, while REST APIs are employed for external interactions. Additionally, we are using the same POJOs generated after proto file compilation.

Controller is looking like

@Slf4j
@RestController
@RequestMapping("/test")
public class TestController {
    @Autowired
    private TestService service;

    @GetMapping(produces = MediaType.APPLICATION_JSON_VALUE, consumes = MediaType.APPLICATION_JSON_VALUE)
    public ResponseEntity<String> getTest(@RequestBody String payload) {
        try {
            GetTestRequest.Builder requestBuilder = GetTestRequest.newBuilder();
            JsonFormat.parser().ignoringUnknownFields().merge(payload, requestBuilder);
            GetTestRequest request = requestBuilder.build();
            GetTestResponse response = service.getTest(request);
            return ResponseEntity.ok(JsonFormat.printer().print(response));
        } catch (Exception e) {
            return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).build();
        }
    }
}

With this code, we are facing an issue in Swagger documentation. As the GetTestRequest is generated from the proto file and is a public static final class type, we cannot use them directly as a request body.

Thanks is advance.

[ejona86]

I don't think we'll have expertise to help you. It sounds like "yes, that doesn't work." But even if there were something to be done about it, this sounds like either a Swagger or Protobuf issue.

[ejona86]

Since you also opened an issue, let's use the issue for follow-ups. (I'm just randomly choosing between the issue and this discussion)

#11025

[panchenko]

This question is not related to gRPC.
In order to simplify the controller code org.springframework.http.converter.protobuf.ProtobufJsonFormatHttpMessageConverter should be used, with spring-boot it's enough to register it as a bean, something like

    @Bean
    ProtobufJsonFormatHttpMessageConverter protobufHttpMessageConverter() {
        return new ProtobufJsonFormatHttpMessageConverter();
    }