"Try it out" does not work in springdoc-openapi-ui? - springdoc-openapi-ui

Question

I use springdoc-openapi-ui:1.6.9 to generate documentation, and I have this controller：
#Operation(summary = "Get a file meta by its ID")
#ApiResponses({
#ApiResponse(responseCode = "200", content = {
#Content(mediaType = MediaType.APPLICATION_JSON_VALUE,
schema = #Schema(implementation = FileMetaResponse.class))
}),
#ApiResponse(responseCode = "404", description = "Not found", content = {
#Content(mediaType = MediaType.TEXT_PLAIN_VALUE,
schema = #Schema(implementation = String.class))
})
})
#RequestMapping(value = "/files/meta", method = RequestMethod.GET)
public ResponseEntity<Object> getFileMate(#RequestParam final #NotEmpty String id) {
OssFile ossFIle = fileService.findFileById(UUID.fromString(id));
if (ossFIle == null) {
return new ResponseEntity<>("File not found", HttpStatus.NOT_FOUND);
}
FileMetaResponse body = new FileMetaResponse();
BeanUtils.copyProperties(ossFIle, body);
return new ResponseEntity<>(body, HttpStatus.OK);
}
But, I always got code 200 and no response body When I execute a request to this API with any id. By debugging code, I found that this request didn't arrive to backend. ui shows：
enter image description here
However, it works normally when I delete response mediatype definition, as follows:
/**
* Get a file meta by given a file ID.
*
* #param id file uuid
* #return a found OssFile meta if successful
*/
#Operation(summary = "Get a file meta by its ID")
#ApiResponses({
#ApiResponse(responseCode = "200", content = {
#Content(
schema = #Schema(implementation = FileMetaResponse.class))
}),
#ApiResponse(responseCode = "404", description = "Not found", content = {
#Content(
schema = #Schema(implementation = String.class))
})
})
#RequestMapping(value = "/files/meta", method = RequestMethod.GET)
public ResponseEntity<Object> getFileMate(#RequestParam final #NotEmpty String id) {
OssFile ossFIle = fileService.findFileById(UUID.fromString(id));
if (ossFIle == null) {
return new ResponseEntity<>("File not found", HttpStatus.NOT_FOUND);
}
FileMetaResponse body = new FileMetaResponse();
BeanUtils.copyProperties(ossFIle, body);
return new ResponseEntity<>(body, HttpStatus.OK);
}
By comparing the two requests, the Accept field of request header is different: the accept is application/json when media type is defined, otherwise the accept is */*.
If I want to define response media type and execute request on swagger-ui web, How should I do?