Apache HTTP/2 Client 5.0 POST request missing payload/content

Question

I have a small sample servlet deployed to a Tomcat that will echo back any received parameters. The Tomcat is configured to support HTTP/1.1 and HTTP/2. I can use curl to make GET requests to the servlet demonstrating it works over both HTTP/1.1 and HTTP/2.

Using the Apache HTTP 5.0 client I have a unit test to hit the servlet and POST a request with some parameters (request content) that works fine - the server receives the parameters and returns them back to the client where I can read them. In this test I call the client to use HTTP/1.1 or HTTP/2 using the CloseableHttpAsyncClient.setVersionPolicy() call. However, if I change to use HTTP/2 then the client does not send the request content to the server.

Below is the example code for a successful HTTP/1.1 call - you can see I have setVersionPolicy(HttpVersionPolicy.FORCE_HTTP_1). If I change that to FORCE_HTTP_2 then the call is made over HTTP/2.0 but the request content is not sent.

Can anyone suggest what I am doing wrong or what extra I need to do? I have not found a lot of documentation on the use of the new Apache 5.0 client libraries, and the examples do not show sending and POST content (or at least those I can find).

    public void testWithHTTP1() throws Exception {

        final String content = "Code=99&Message=Hello";
        final String contentType = "application/text";

        final CloseableHttpAsyncClient client = HttpAsyncClients.custom()
                .setVersionPolicy(HttpVersionPolicy.FORCE_HTTP_1)
                .build();

        client.start();

        final HttpHost target = new HttpHost("http","localhost",8002);
        final String requestUri = "/VSFTestMT_Test/Test/Test_EchoHttpGet";

        final HttpClientContext clientContext = HttpClientContext.create();

        final SimpleHttpRequest httppost = SimpleHttpRequests.post(target, requestUri);     
        httppost.setBody(content, ContentType.create("application.x_www_form_urlencoded"));
        
        final Future<SimpleHttpResponse> future = client.execute(
                httppost,
                clientContext,
                new FutureCallback<SimpleHttpResponse>() {

                    @Override
                    public void completed(final SimpleHttpResponse response) {
                        System.out.println(requestUri + "->" + response.getCode());
                        System.out.println(response.getBody());
                    }

                    @Override
                    public void failed(final Exception ex) {
                        System.out.println(requestUri + "->" + ex);
                    }

                    @Override
                    public void cancelled() {
                        System.out.println(requestUri + " cancelled");
                    }

                });


        System.out.println("Shutting down");
        client.close(CloseMode.GRACEFUL);
    }

Post the wire log of the session either here or to httpclient-users@hc.apache.org — ok2c, Mar 07 '21 at 15:39

score 2 · Accepted Answer · answered Mar 02 '21 at 15:03

2

HTTP/1 can be implemented via HTTP and HTTPS, but for HTTP/2 its implemented in HTTPS only.

From what I can see you are calling http url only, might be that is the reason why servlet is not able to fetch payload content

Please see this more detail

answered Mar 02 '21 at 15:03

Wang Du

101
2

Thank you, that lead me to do some more testing with CURL. I had thought my tomcat server was OK with HTTP/2 on both HTTP and HTTPS. However the use of HTTP/2 is not so clear cut. I can use CURL to do HTTP/2 POST requests on the non-SSL connections but only if there is no payload. I can also do HTTP/2 GET requests with or without URL parameters on both HTTP and HTTPS. So it seems that adding body content to a non-SSL HTTP/2 request will downgrade to HTTP/1. In my tests I can add body content to the HTTP/2 request successfully so as you point out I need to make my requests to the HTTPS server. – JohnXF Mar 02 '21 at 18:06

score 0 · Answer 2 · answered Mar 02 '21 at 13:20

It looks like they have a completly different builder for Http/2 looking at their sourcecode:

/**
 * Creates builder object for construction of custom HTTP/2
 * {@link CloseableHttpAsyncClient} instances optimized for HTTP/2 protocol
 * and message multiplexing
 */
public static H2AsyncClientBuilder customHttp2() {
    return H2AsyncClientBuilder.create();
}

/**
 * Creates HTTP/2 {@link CloseableHttpAsyncClient} instance with default configuration and
 * system properties optimized for HTTP/2 protocol and message multiplexing.
 */
public static CloseableHttpAsyncClient createHttp2System() {
    return H2AsyncClientBuilder.create().useSystemProperties().build();
}

Therefore I suggest you try the actual customHttp2(), instead of custom().

https://github.com/apache/httpcomponents-client/blob/master/httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/HttpAsyncClients.java

Thanks Susan, but no joy there. Using customHttp2() will give me a ClientBuilder from which I get another CloseableHttpAsyncClient, but proceeding as before I still then get the same result. — JohnXF, Mar 02 '21 at 14:57
@Susan Mustafa This builder is intended for those users who would like to use HTTP/2 protocol only and take full advantage of message exchange multiplexing. — ok2c, Mar 07 '21 at 16:29

Apache HTTP/2 Client 5.0 POST request missing payload/content

2 Answers2