In my code I have simple Feign client:
@FeignClient(name = "client", url = "${spring.microservice.tenant-auth.host}")
public interface PerTenantTokenClient {
@PostMapping(consumes = MediaType.APPLICATION_FORM_URLENCODED_VALUE)
ResponseEntity<AuthenticationResponse> getAuthToken(AuthFormData formData);
}
aimed to execute the following request:
POST https://myhost.net/oauth/token
Content-Type: application/x-www-form-urlencoded
grant_type = client_credentials &
client_id = id &
client_secret = secret
getAuthToken()
method accepts a payload DTO described as:
@RequiredArgsConstructor
public class AuthFormData {
private final String grant_type;
private final String client_id;
private final String client_secret;
}
When I run this code snippet:
AuthFormData authFormData = new AuthFormData("client_credentials", "id", "secret");
var authTokenResponse = client.getAuthToken(authFormData);
it unexpectedly fails with 400:
[400 Bad Request] during [POST] to [https://myhost.net/oauth/token] [PerTenantTokenClient#getAuthToken(AuthFormData)]: [{
"error" : "invalid_request",
"error_description" : "Missing parameter: grant_type"
}]
However, if I remove final
from AuthFormData
fields' declaration the same code succeeds.
I've tried to declare AuthFormData
as Java record and it fails either (apparently due to implicit final
on record members).
So my question is whether I'm facing a bug in feign client or something is wrong with my code? I use io.github.openfeign:feign-core:13.1
and Java 21
This is a bug, see the following links: