Question

我正在寻找可以连接到基于HTTP / 2的服务器的java客户端..服务器已经支持HTTP / 2 API。我还没有看到仍然支持HTTP / 2的最流行的Apache Http客户端https://hc.apache.org/。

Apache是否已经为支持Http / 2的Java客户端实现了一些实现？

如果没有，是否有一些Java客户端支持连接到HTTP / 2，最好是在Java 7上？

Answer 1

Jetty提供了两个HTTP / 2 Java客户端API。两者都需要Java 8和强制使用ALPN，如here所述。

低级API

这些API基于HTTP2Client，它基于会话和流的HTTP / 2概念，并使用侦听器进行通知从服务器到达的HTTP / 2 帧。

if ($().selectpicker) 
{
  $('.selectpicker').selectpicker();
}

高级API

Jetty的// 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(); } });提供了一种使用different transports的方法，其中一个是HTTP/2 transport。应用程序将使用更高级别的HTTP API，但Jetty下面将使用HTTP / 2来传输HTTP语义。

通过这种方式，应用程序可以透明地使用HttpClient提供的高级API，并分析在配置或启动代码中使用的传输。

HttpClient

Answer 2

有OkHttp: An HTTP & HTTP/2 client for Android and Java applications。

Answer 3

从版本9.3开始，Jetty支持HTTP2。这包括服务器和the client。

Answer 4

Apache httpclient-5 beta支持jdk9或更高版本的http / 2

示例：

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);
}

引用：https://hc.apache.org/httpcomponents-client-5.0.x/examples-async.html

Apache或其他一些CLIENT JAVA实现是否支持HTTP / 2？

4 个答案:

低级API

高级API