ok2c commented on a change in pull request #128: Added Greeting Example URL: https://github.com/apache/httpcomponents-core/pull/128#discussion_r289606287
########## File path: httpcore5-h2/src/test/java/org/apache/hc/core5/http2/examples/Http2GreetingServer.java ########## @@ -0,0 +1,199 @@ +/* + * ==================================================================== + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + * ==================================================================== + * + * This software consists of voluntary contributions made by many + * individuals on behalf of the Apache Software Foundation. For more + * information on the Apache Software Foundation, please see + * <http://www.apache.org/>. + * + */ +package org.apache.hc.core5.http2.examples; + +import org.apache.hc.core5.function.Supplier; +import org.apache.hc.core5.http.ContentType; +import org.apache.hc.core5.http.EndpointDetails; +import org.apache.hc.core5.http.EntityDetails; +import org.apache.hc.core5.http.HttpException; +import org.apache.hc.core5.http.HttpHeaders; +import org.apache.hc.core5.http.HttpRequest; +import org.apache.hc.core5.http.HttpResponse; +import org.apache.hc.core5.http.Message; +import org.apache.hc.core5.http.NameValuePair; +import org.apache.hc.core5.http.impl.bootstrap.HttpAsyncServer; +import org.apache.hc.core5.http.message.BasicHttpResponse; +import org.apache.hc.core5.http.nio.AsyncEntityConsumer; +import org.apache.hc.core5.http.nio.AsyncRequestConsumer; +import org.apache.hc.core5.http.nio.AsyncServerExchangeHandler; +import org.apache.hc.core5.http.nio.AsyncServerRequestHandler; +import org.apache.hc.core5.http.nio.BasicRequestConsumer; +import org.apache.hc.core5.http.nio.BasicResponseProducer; +import org.apache.hc.core5.http.nio.entity.NoopEntityConsumer; +import org.apache.hc.core5.http.nio.entity.StringAsyncEntityConsumer; +import org.apache.hc.core5.http.nio.entity.StringAsyncEntityProducer; +import org.apache.hc.core5.http.nio.support.AbstractServerExchangeHandler; +import org.apache.hc.core5.http.protocol.HttpContext; +import org.apache.hc.core5.http.protocol.HttpCoreContext; +import org.apache.hc.core5.http2.HttpVersionPolicy; +import org.apache.hc.core5.http2.config.H2Config; +import org.apache.hc.core5.http2.impl.nio.bootstrap.H2ServerBootstrap; +import org.apache.hc.core5.io.CloseMode; +import org.apache.hc.core5.net.URLEncodedUtils; +import org.apache.hc.core5.reactor.IOReactorConfig; +import org.apache.hc.core5.reactor.ListenerEndpoint; +import org.apache.hc.core5.util.TimeValue; + +import java.io.IOException; +import java.net.InetSocketAddress; +import java.nio.charset.UnsupportedCharsetException; +import java.util.Date; +import java.util.List; +import java.util.concurrent.ExecutionException; +import java.util.concurrent.Future; + +/** + * Example HTTP2 server that reads an entity body and responds back with a greeting. + * + * <pre> + * {@code + * $ curl -id name=bob localhost:8080 + * HTTP/1.1 200 OK + * Date: Sat, 25 May 2019 03:44:49 GMT + * Server: Apache-HttpCore/5.0-beta8-SNAPSHOT (Java/1.8.0_202) + * Transfer-Encoding: chunked + * Content-Type: text/plain; charset=ISO-8859-1 + * + * Hello bob + * }</pre> + * <p> + * This examples uses a {@link AbstractServerExchangeHandler} for the basic Request/Response cycle (consuming requests + * and producing responses) and either a {@link NoopEntityConsumer} or {@link InputStreamEntity} depending if the + * request has a body/content or not. + * </p> + * Further improvements left as an exercise for the reader: + * <ul> + * <li>TLS</li> + * <li>Handle of multipart requests</li> + * </ul> + */ +public class Http2GreetingServer { + public static void main(final String[] args) throws ExecutionException, InterruptedException { + int port = 8080; + if (args.length >= 1) { + port = Integer.parseInt(args[0]); + } + + final HttpAsyncServer server = H2ServerBootstrap.bootstrap() + .setH2Config(H2Config.DEFAULT) + .setIOReactorConfig(IOReactorConfig.DEFAULT) + .setVersionPolicy(HttpVersionPolicy.NEGOTIATE) // fallback to HTTP/1 as needed + + // wildcard path matcher: + .register("*", new Supplier<AsyncServerExchangeHandler>() { + @Override + public AsyncServerExchangeHandler get() { + return new CustomServerExchangeHandler(); + } + }) + .create(); + + + Runtime.getRuntime().addShutdownHook(new Thread(new Runnable() { + @Override + public void run() { + System.out.println("HTTP server shutting down"); + server.close(CloseMode.GRACEFUL); + } + })); + + server.start(); + final Future<ListenerEndpoint> future = server.listen(new InetSocketAddress(port)); + final ListenerEndpoint listenerEndpoint = future.get(); + System.out.println("Listening on " + listenerEndpoint.getAddress()); + server.awaitShutdown(TimeValue.ofDays(Long.MAX_VALUE)); + } + + static class CustomServerExchangeHandler extends AbstractServerExchangeHandler<Message<HttpRequest, String>> { + + + @Override + protected AsyncRequestConsumer<Message<HttpRequest, String>> supplyConsumer(final HttpRequest request, + final EntityDetails + entityDetails, + final HttpContext context) { + // if there's no body don't try to parse entity: + AsyncEntityConsumer entityConsumer = new NoopEntityConsumer(); + + if (entityDetails != null) { + entityConsumer = new StringAsyncEntityConsumer(); + } + return new BasicRequestConsumer<String>(entityConsumer); + + } + + @Override + protected void handle(final Message<HttpRequest, String> requestMessage, + final AsyncServerRequestHandler.ResponseTrigger responseTrigger, + final HttpContext context) throws HttpException, IOException { + + try { + final HttpCoreContext coreContext = HttpCoreContext.adapt(context); + final EndpointDetails endpoint = coreContext.getEndpointDetails(); + final HttpRequest req = requestMessage.getHead(); + final String httpEntity = requestMessage.getBody(); + + // generic success response: + final HttpResponse resp = new BasicHttpResponse(200); + + // recording the request + System.out.println(String.format("[%s] %s %s %s", new Date(), + endpoint.getRemoteAddress().toString(), + req.getMethod(), + req.getPath())); + + // Request without an entity - GET/HEAD/DELETE + if (httpEntity == null) { + responseTrigger.submitResponse(new BasicResponseProducer(resp), context); + return; + } + + // Request with an entity - POST/PUT + final ContentType entityContentType = ContentType.parse(req.getHeader(HttpHeaders.CONTENT_TYPE).getValue()); + String greeting = "Hello stranger\n"; + + if (entityContentType.getMimeType().equals(ContentType.APPLICATION_FORM_URLENCODED.getMimeType())) { + + // decoding the form entity into key/value pairs: + final List<NameValuePair> args = URLEncodedUtils.parse(httpEntity, + ContentType.APPLICATION_FORM_URLENCODED.getCharset()); + + // composing greeting: + greeting = String.format("Hello %s\n", args.get(0).getValue()); + } + + responseTrigger.submitResponse(new BasicResponseProducer(resp, + new StringAsyncEntityProducer(greeting, ContentType.TEXT_PLAIN)), context); + } catch (final HttpException | UnsupportedCharsetException | IOException e) { + throw new IllegalStateException(e); Review comment: @rferreira Much better, but I still dislike exception handling code. There is no need to re-throw `HttpException` and `IOException` as `IllegalStateException`. Those exceptions do not represent illegal service state. They are perfectly legal. Either handle them in your handler and return a valid HTTP message back to the caller, or let the framework do it for you. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
