FluentAsyncCompletableFuture.java

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 * 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.
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 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
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package org.apache.hc.client5.http.examples.fluent;

import java.util.Arrays;
import java.util.List;
import java.util.concurrent.CompletableFuture;

import org.apache.hc.client5.http.fluent.Async;
import org.apache.hc.client5.http.fluent.Request;

/**
 * This example demonstrates how the HttpClient fluent API can be used to execute multiple
 * requests asynchronously using CompletableFuture.
 */
public class FluentAsyncCompletableFuture {

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

        final List<Request> requests = Arrays.asList(
                Request.get("http://www.google.com/"),
                Request.get("http://www.yahoo.com/"),
                Request.get("http://www.apache.org/"),
                Request.get("http://www.apple.com/")
        );

        final Async async = Async.newInstance().useDefaultExecutor(8, 500);
        try {

            final CompletableFuture<?>[] futures = requests.stream()
                    .map(r -> async.executeAsync(r)
                            .thenAccept(content -> System.out.println("Request completed: " + r))
                            .exceptionally(ex -> {
                                System.out.println(ex.getMessage() + ": " + r);
                                return null;
                            }))
                    .toArray(CompletableFuture[]::new);

            CompletableFuture.allOf(futures).join();
        } finally {
            async.shutdown();
        }

        System.out.println("Done");
    }

}