httpclient5/src/test/java/org/apache/hc/client5/http/examples/AsyncClientMessageTrailers.java

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 * 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.client5.http.examples;

import java.io.IOException;
import java.util.concurrent.Future;

import org.apache.hc.client5.http.async.AsyncExecCallback;
import org.apache.hc.client5.http.async.AsyncExecChain;
import org.apache.hc.client5.http.async.AsyncExecChainHandler;
import org.apache.hc.client5.http.async.methods.SimpleHttpResponse;
import org.apache.hc.client5.http.async.methods.SimpleResponseConsumer;
import org.apache.hc.client5.http.impl.ChainElements;
import org.apache.hc.client5.http.impl.async.CloseableHttpAsyncClient;
import org.apache.hc.client5.http.impl.async.HttpAsyncClients;
import org.apache.hc.core5.concurrent.FutureCallback;
import org.apache.hc.core5.http.ContentType;
import org.apache.hc.core5.http.HttpException;
import org.apache.hc.core5.http.HttpRequest;
import org.apache.hc.core5.http.nio.AsyncEntityProducer;
import org.apache.hc.core5.http.nio.AsyncRequestProducer;
import org.apache.hc.core5.http.nio.entity.DigestingEntityProducer;
import org.apache.hc.core5.http.nio.entity.StringAsyncEntityProducer;
import org.apache.hc.core5.http.nio.support.AsyncRequestBuilder;
import org.apache.hc.core5.io.CloseMode;
import org.apache.hc.core5.reactor.IOReactorConfig;
import org.apache.hc.core5.util.Timeout;

/**
 * This example demonstrates how to use a custom execution interceptor
 * to add trailers to all outgoing request enclosing an entity.
 */
public class AsyncClientMessageTrailers {

    public final static void main(final String[] args) throws Exception {

        final IOReactorConfig ioReactorConfig = IOReactorConfig.custom()
                .setSoTimeout(Timeout.ofSeconds(5))
                .build();

        final CloseableHttpAsyncClient client = HttpAsyncClients.custom()
                .setIOReactorConfig(ioReactorConfig)
                .addExecInterceptorAfter(ChainElements.PROTOCOL.name(), "custom", new AsyncExecChainHandler() {

                    @Override
                    public void execute(
                            final HttpRequest request,
                            final AsyncEntityProducer entityProducer,
                            final AsyncExecChain.Scope scope,
                            final AsyncExecChain chain,
                            final AsyncExecCallback asyncExecCallback) throws HttpException, IOException {
                        // Send MD5 hash in a trailer by decorating the original entity producer
                        chain.proceed(
                                request,
                                entityProducer != null ? new DigestingEntityProducer("MD5", entityProducer) : null,
                                scope,
                                asyncExecCallback);
                    }

                })
                .build();

        client.start();

        final String requestUri = "http://httpbin.org/post";
        final AsyncRequestProducer requestProducer = AsyncRequestBuilder.post(requestUri)
                .setEntity(new StringAsyncEntityProducer("some stuff", ContentType.TEXT_PLAIN))
                .build();
        final Future<SimpleHttpResponse> future = client.execute(
                requestProducer,
                SimpleResponseConsumer.create(),
                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");
                    }

                });
        future.get();

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

}