org.springframework.integration.samples.helloworld.HelloService.java Source code

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Here is the source code for org.springframework.integration.samples.helloworld.HelloService.java

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/*
 * Copyright 2002-2012 the original author or authors.
 *
 * 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 org.springframework.integration.samples.helloworld;

import com.google.common.util.concurrent.*;
import org.apache.commons.io.IOUtils;
import org.springframework.scheduling.annotation.Async;
import org.springframework.scheduling.annotation.AsyncResult;
import org.springframework.scheduling.annotation.EnableAsync;

import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;

/**
 * Simple POJO to be referenced from a Service Activator.
 *
 * @author Mark Fisher
 */
@EnableAsync
public class HelloService {

    public String sayHello(String name) {
        return "Hello " + name;
    }

    public String downloadContents(URL url) throws IOException {
        try (InputStream input = url.openStream()) {
            return IOUtils.toString(input, StandardCharsets.UTF_8);
        }
    }

    private final ExecutorService poop = Executors.newFixedThreadPool(10);

    public Future<String> downloadContentsWithFuture(final URL url) throws IOException {

        return poop.submit(new Callable<String>() {
            @Override
            public String call() throws Exception {
                try (InputStream input = url.openStream()) {
                    return IOUtils.toString(input, StandardCharsets.UTF_8);
                }
            }
        });

    }

    @Async
    public Future<String> downloadContentsWithFutureAsync(final URL url) throws IOException {

        try (InputStream input = url.openStream()) {
            return new AsyncResult<>(IOUtils.toString(input, StandardCharsets.UTF_8));
        }

    }

    public void doGuavaDownloadWithChainedThreads(final URL url) throws IOException {
        ListeningExecutorService service = MoreExecutors.listeningDecorator(Executors.newFixedThreadPool(10));
        List<ListenableFuture<String>> calls = new ArrayList<ListenableFuture<String>>();
        while (calls.size() < 5) {
            com.google.common.util.concurrent.ListenableFuture<String> call = service
                    .submit(new Callable<String>() {
                        @Override
                        public String call() throws Exception {
                            try (InputStream input = url.openStream()) {
                                return IOUtils.toString(input, StandardCharsets.UTF_8);
                            }
                        }
                    });
            calls.add(call);
        }

        ListenableFuture<List<String>> goodCalls = Futures.successfulAsList(calls);
        Futures.addCallback(goodCalls, new FutureCallback<List<String>>() {
            @Override
            public void onSuccess(List<String> strings) {
                System.out.print("Successful call");
            }

            @Override
            public void onFailure(Throwable throwable) {
                System.err.println("Problems");
            }
        });

    }

}