com.amitinside.java8.concurrency.CompletableFutureInAction.java Source code

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Here is the source code for com.amitinside.java8.concurrency.CompletableFutureInAction.java

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/*******************************************************************************
 * Copyright 2016 Amit Kumar Mondal
 *
 * Licensed 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.
 *******************************************************************************/
package com.amitinside.java8.concurrency;

import java.io.IOException;
import java.net.URL;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

import org.apache.commons.io.IOUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.w3c.dom.Document;

import com.google.common.base.Throwables;
import com.google.common.collect.Lists;

public final class CompletableFutureInAction {

    private static final ExecutorService executor = Executors.newFixedThreadPool(4);

    private static final Logger logger = LoggerFactory.getLogger(CompletableFutureInAction.class);

    private static CompletableFuture<Double> calculateRelevance(final Document doc) {
        return null;
    }

    private static String downloadSite(final String site) {
        try {
            logger.debug("Downloading {}", site);
            final String res = IOUtils.toString(new URL("http://" + site).openStream(), "UTF-8");
            logger.debug("Done {}", site);
            return res;
        } catch (final IOException e) {
            throw Throwables.propagate(e);
        }
    }

    public static void main(final String[] args) {
        Lists.newArrayList("www.google.com", "www.youtube.com", "www.yahoo.com", "www.msn.com");

        // final List<CompletableFuture<Double>> relevanceFutures =
        // topSites.stream()
        // .map(site -> CompletableFuture.supplyAsync(() -> downloadSite(site),
        // executor))
        // .map(contentFuture -> contentFuture.thenApply(this::parse))
        // .map(docFuture -> docFuture.thenCompose(this::calculateRelevance))
        // .collect(Collectors.<CompletableFuture<Double>> toList());
    }

    private static Document parse(final String xml) {
        return null;
    }

}