Flupke is a Java HTTP3 implementation that runs on top of Kwik.
HTTP3 is a new standard that has been developed by the Internet Engineering Task Force (IETF) and is specified by RFC 9114. HTTP3 uses QUIC as transport protocol and QPACK for header compression. Flupke builds on Kwik, a Java implementation of QUIC; header compression is supported by the QPACK library.
Initially, Flupke was only a HTTP3 Client, but since June 2021 it also provides a plugin that, when used with Kwik, acts as a (simple) HTTP3 webserver server.
Flupke is created and maintained by Peter Doornbosch. The latest greatest can always be found on BitBucket.
Latest release can be found at maven central:
<dependency>
<groupId>tech.kwik</groupId>
<artifactId>flupke</artifactId>
<version>0.5.3</version>
</dependency>
Flupke uses the HTTP Client API introduced with Java 11, e.g.
HttpClient.Builder clientBuilder = new Http3ClientBuilder();
HttpClient client = clientBuilder.build();
HttpResponse<String> httpResponse = client.send(request, HttpResponse.BodyHandlers.ofString());
See the Sample class for a working example.
Flupke also supports POST requests, or more generally, HTTP methods that require or use a request body. See the PostExample for details.
This project (as well as the projects it builds on) is work in progress.
Features:
- HTTP3 request & response with all methods (GET, PUT, POST etc)
- Multiplexing of HTTP3 requests over one underlying QUIC connection
- Support for asynchronous handling with
HttpClient.sendAsync()
Limitations in the current version:
- QPack dynamic table is not supported, neither does the QPack encoder use Huffman encoding. Note that even with these limitations, Flupke can talk to any HTTP/3 compliant server.
- No support for server push.
- No support for CONNECT method.
- No support for GOAWAY.
Also note that Http3Client.version() returns null instead of a proper Version object;
this is unavoidable as the Java HTTPClient.Version
enum does not provide a value for HTTP3. See JDK-8229533.
Building is done by gradle; the gradle wrapper is included in the sources, so after checking out the source, just run
./gradlew build
which will run the unit tests and create the flupke.jar file in build/libs.
This flupke.jar contains the Flupke library (including QPack classes).
When using in your own project, you will also need the Kwik dependency, which you can fetch from Maven Central.
Alternatively, you can build the uberjar, which contains all dependencies and provides a runnable sample client. To build the uberjar, run
./gradlew uberjar
To run the sample client, use the provided flupke.sh shell script and pass the targer URL as a parameter.
You can also run the java command directly:
java -cp build/libs/flupke-uber.jar net.luminis.http3.sample.Sample <URL>
Whether the URL is specified with HTTP or HTTPS protocol doesn't matter, Flupke will always (and only) try to set up a QUIC connection. The port specified in the URL must be the UDP port on which the HTTP3/QUIC server listens.
Gradle can also generate IntelliJ Idea project files for you:
gradle idea
By default, Flupke will use QUIC version 1 (the official RFC version). To let Flupke use a different QUIC version (e.g. QUIC version 2, RFC 9369), put the version in an environment variable called "QUIC_VERSION" (for QUIC version 2, use the value "2" (without the quotes)).
The project requires Java 11.
If you have questions about this project, please mail the author (peter dot doornbosch) at luminis dot eu.
Thanks to Piet van Dongen for creating the marvellous logo!
This program is open source and licensed under LGPL (see the LICENSE.txt and LICENSE-LESSER.txt files in the distribution). This means that you can use this program for anything you like, and that you can embed it as a library in other applications, even commercial ones. If you do so, the author would appreciate if you include a reference to the original.
As of the LGPL license, all modifications and additions to the source code must be published as (L)GPL as well.