I'm looking for java client that can connect to a HTTP/2 based server.. The server is already supporting HTTP/2 API. I don't see the most popular Apache Http client https://hc.apache.org/ still supporting HTTP/2.
Does Apache have some implementation for Java client already that supports Http/2?
If not, Is there some java client that supports connecting to HTTP/2 preferably on Java 7?
Jetty's provides two HTTP/2 Java client APIs. Both require Java 8 (or better) and the mandatory use of the ALPN, as explained here.
These APIs are based on HTTP2Client, it's based on the HTTP/2 concepts of session and streams and uses listeners to be notified of the HTTP/2 frames that arrive from the server.
// Setup and start the HTTP2Client.
HTTP2Client client = new HTTP2Client();
SslContextFactory sslContextFactory = new SslContextFactory();
client.addBean(sslContextFactory);
client.start();
// Connect to the remote host to obtains a Session.
FuturePromise<Session> sessionPromise = new FuturePromise<>();
client.connect(sslContextFactory, new InetSocketAddress(host, port), new ServerSessionListener.Adapter(), sessionPromise);
Session session = sessionPromise.get(5, TimeUnit.SECONDS);
// Use the session to make requests.
HttpFields requestFields = new HttpFields();
requestFields.put("User-Agent", client.getClass().getName() + "/" + Jetty.VERSION);
MetaData.Request metaData = new MetaData.Request("GET", new HttpURI("https://webtide.com/"), HttpVersion.HTTP_2, requestFields);
HeadersFrame headersFrame = new HeadersFrame(metaData, null, true);
session.newStream(headersFrame, new Promise.Adapter<>(), new Stream.Listener.Adapter()
{
@Override
public void onHeaders(Stream stream, HeadersFrame frame)
{
// Response headers.
System.err.println(frame);
}
@Override
public void onData(Stream stream, DataFrame frame, Callback callback)
{
// Response content.
System.err.println(frame);
callback.succeeded();
}
});
Jetty's HttpClient provides a way to use different transports, one of which is the HTTP/2 transport. Applications will use the higher level HTTP APIs, but underneath Jetty will use HTTP/2 to transport the HTTP semantic.
In this way, applications can use the high level APIs provided by HttpClient transparently, and factor out what transport to use in configuration or startup code.
// Setup and start HttpClient with HTTP/2 transport.
HTTP2Client http2Client = new HTTP2Client();
SslContextFactory sslContextFactory = new SslContextFactory();
HttpClient httpClient = new HttpClient(new HttpClientTransportOverHTTP2(http2Client), sslContextFactory);
httpClient.start();
// Make a request.
ContentResponse response = httpClient.GET("https://webtide.com/");
Jetty has support for HTTP2 starting from version 9.3. This includes the server and the client.
Apache httpclient-5 beta supports http/2 from jdk9 or above
example :
public static void main(final String[] args) throws Exception {
final SSLContext sslContext = SSLContexts.custom().loadTrustMaterial(new TrustAllStrategy()).build();
final PoolingAsyncClientConnectionManager connectionManager = PoolingAsyncClientConnectionManagerBuilder.create().setTlsStrategy(new H2TlsStrategy(sslContext, NoopHostnameVerifier.INSTANCE)).build();
final IOReactorConfig ioReactorConfig = IOReactorConfig.custom().setSoTimeout(Timeout.ofSeconds(5)).build();
final MinimalHttpAsyncClient client = HttpAsyncClients.createMinimal(HttpVersionPolicy.FORCE_HTTP_2, H2Config.DEFAULT, null, ioReactorConfig, connectionManager);
client.start();
final HttpHost target = new HttpHost("localhost", 8082, "https");
final Future<AsyncClientEndpoint> leaseFuture = client.lease(target, null);
final AsyncClientEndpoint endpoint = leaseFuture.get(10, TimeUnit.SECONDS);
try {
String[] requestUris = new String[] {"/"};
CountDownLatch latch = new CountDownLatch(requestUris.length);
for (final String requestUri: requestUris) {
SimpleHttpRequest request = SimpleHttpRequest.get(target, requestUri);
endpoint.execute(SimpleRequestProducer.create(request), SimpleResponseConsumer.create(), new FutureCallback<SimpleHttpResponse>() {
@Override
public void completed(final SimpleHttpResponse response) {
latch.countDown();
System.out.println(requestUri + "->" + response.getCode());
System.out.println(response.getBody());
}
@Override
public void failed(final Exception ex) {
latch.countDown();
System.out.println(requestUri + "->" + ex);
ex.printStackTrace();
}
@Override
public void cancelled() {
latch.countDown();
System.out.println(requestUri + " cancelled");
}
});
}
latch.await();
} catch (Exception e) {
e.printStackTrace();
}finally {
endpoint.releaseAndReuse();
}
client.shutdown(ShutdownType.GRACEFUL);
}
refer : https://hc.apache.org/httpcomponents-client-5.0.x/examples-async.html
