Grizzly 2.4.4/4.0.0 missing Content-Type in response

[rabbit20210221]

Response from Grizzly http server does not contain Content-Type header when client includes HTTP 2 upgrade headers.

I am not interested in HTTP 2 support, but expect Grizzly to give HTTP 1.1 response with Content-Type header.

Test program:

public static void main(String[] args) throws IOException, InterruptedException {
        HttpServer server = HttpServer.createSimpleServer();
        server.getServerConfiguration().addHttpHandler(new HttpHandler() {
            public void service(Request request, Response response)
                    throws Exception {
                for (String header: request.getHeaderNames()) {
                    String value = String.join("," , request.getHeaders(header));
                    System.out.println("<< " + header + "=" + value);
                }
                final String date = "{ "
                        + "\"name\": \"" + server.getServerConfiguration().getHttpServerName() + ","
                        + "\"version\": \"" + server.getServerConfiguration().getHttpServerVersion() + ","
                        + "\"time\": \"" + Instant.now().toString() 
                    + "\" }";
                response.setContentType("application/json");
                response.setContentLength(date.length());
                response.setCharacterEncoding("UTF-8");
                response.getWriter().write(date);
            }
        }, "/time");
        server.start();
        NetworkListener listener = server.getListener("grizzly");

        HttpRequest request = HttpRequest.newBuilder()
                .GET()
                .uri(URI.create("http://127.0.0.1:" + listener.getPort() + "/time"))
                .setHeader("Accept", "application/json")
                .build();

        System.out.println("\n\nDefault HttpClient with Upgrade h2c");
        HttpClient httpClient1 = HttpClient.newBuilder()
                .connectTimeout(Duration.ofSeconds(30))
                .build();
        HttpResponse<String> response1 = httpClient1.send(request, HttpResponse.BodyHandlers.ofString());
        HttpHeaders headers1 = response1.headers();
        headers1.map().forEach((k, v) -> System.out.println(">> " + k + ":" + v));
        System.out.println(response1.statusCode());
        System.out.println(response1.body());

        System.out.println("\n\nHttpClient 1.1");
        HttpClient httpClient2 = HttpClient.newBuilder()
                .version(HttpClient.Version.HTTP_1_1)
                .connectTimeout(Duration.ofSeconds(30))
                .build();
        HttpResponse<String> response2 = httpClient2.send(request, HttpResponse.BodyHandlers.ofString());
        HttpHeaders headers2 = response2.headers();
        headers2.map().forEach((k, v) -> System.out.println(">>" + k + ":" + v));
        System.out.println(response2.statusCode());
        System.out.println(response2.body());
    }

Output:

Default HttpClient with Upgrade h2c
<< connection=Upgrade, HTTP2-Settings
<< content-length=0
<< host=127.0.0.1:8080
<< http2-settings=AAEAAEAAAAIAAAABAAMAAABkAAQBAAAAAAUAAEAA
<< upgrade=h2c
<< user-agent=Java-http-client/11.0.20
<< accept=application/json
>> content-length:[44]
200
{ "name": "Grizzly,"version": "4.0.0,"time": "2023-10-07T00:37:10.670102600Z" }

HttpClient 1.1
<< content-length=0
<< host=127.0.0.1:8080
<< user-agent=Java-http-client/11.0.20
<< accept=application/json
>>content-length:[41]
>>content-type:[application/json;charset=UTF-8]
200
{ "name": "Grizzly,"version": "4.0.0,"time": "2023-10-07T00:40:06.860429100Z" }

Note missing "content-type" in the first response.

[mnriem]

1. Can you reproduce this on the latest Grizzly version?
2. Can you reproduce this with another HttpClient library?

[rabbit20210221]

1. Grizzly 2.4.4 is already the latest of the 2.x.x series. I cannot upgrade to Grizzly 4.x.x as my code base is not migrated to Jakarta EE yet.
2. This is reproducible with any HTTP client library -- even with "curl" command line. All you need to trigger the bug is the presence of "Upgrade: h2c" in client request.

[mnriem]

1. Can you try it with the latest Grizzly 4 and your test program?
2. Can you share the curl command line?

[rabbit20210221]

Thanks for your response. I ran the test with Grizzly 4.0.0 and found the same issue with curl. I modifed my original test program to include Grizzly version in response.

Test 1: curl GET -- no issues

$ curl -vv -H 'Accept: application/json' http://localhost:8080/time
*   Trying 127.0.0.1:8080...
* Connected to localhost (127.0.0.1) port 8080 (#0)
> GET /time HTTP/1.1
> Host: localhost:8080
> User-Agent: curl/8.0.1
> Accept: application/json
>
< HTTP/1.1 200 OK
< Content-Type: application/json;charset=UTF-8
< Content-Length: 79
<
{ "name": "Grizzly,"version": "4.0.0,"time": "2023-10-07T00:37:10.670102600Z" }

Test 2: curl GET with "Upgrade: h2c" -- missing Content-Type header in Grizzly response

$ curl -vv -H 'Accept: application/json' -H 'Upgrade: h2c' http://localhost:8080/time
*   Trying 127.0.0.1:8080...
* Connected to localhost (127.0.0.1) port 8080 (#0)
> GET /time HTTP/1.1
> Host: localhost:8080
> User-Agent: curl/8.0.1
> Accept: application/json
> Upgrade: h2c
>
< HTTP/1.1 200 OK
< Content-Length: 76
<
{ "name": "Grizzly,"version": "4.0.0,"time": "2023-10-07T00:38:20.201669Z" }

[mnriem]

@rabbit20210221 I have confirmed the issue and looking into a fix

[rabbit20210221]

@mnriem Thanks for your quick reply.

[mnriem]

@rabbit20210221 Can you try out the PR?