App.java

package com.mars;

import akka.actor.UntypedActor;
import com.google.common.base.Stopwatch;
import com.google.common.collect.Lists;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.RandomStringUtils;

import java.util.List;
import java.util.Optional;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorCompletionService;
import java.util.concurrent.Executors;
import java.util.concurrent.atomic.AtomicReference;
import java.util.stream.Collectors;

/**
 * Hello world!
 */
@Slf4j
public class App {

    public static void main(String[] args) {
        log.info("Hello World!");
        String question = "Test123";
        List<String> engines = Lists.newArrayList();
        for (int i = 0; i < 100; i++) {
            engines.add(RandomStringUtils.randomAlphanumeric(10));
        }
        engines.add(question);
        Stopwatch stopwatch = Stopwatch.createStarted();
        String actual = getFirstResultByThread(question, engines);
        stopwatch.stop();
        log.info("actual = " + actual);

    }

    private static String getFirstResultByThread(String question, List<String> engines) {
        AtomicReference<String> result = new AtomicReference<>();
        for (String base : engines) {
            new Thread(() -> {
//                String url = base + question;
//                result.compareAndSet(null, WS.url(url).get());
                if (base.equals(question)) {
                    result.compareAndSet(question, "Hello " + question);
                }
            }).start();
        }
        while (result.get() == null) ;
        return result.get();
    }

//    private static String getFirstResultExecutors(String question, List<String> engines) {
//        ExecutorCompletionService<String> service = new ExecutorCompletionService<>(Executors.newFixedThreadPool(4));
//        for (String base : engines) {
//            String url = base + question;
//            service.submit(() -> {
////                return WS.url(url).get();
//                if (base.equals(question)) {
//                    return question;
//                }
//            });
//        }
//        try {
//            return service.take().get();
//        } catch (InterruptedException | ExecutionException e) {
//            return null;
//        }
//    }
//
//    private static String getFirstResult(String question, List<String> engines) {
//        Optional<String> result = engines.stream().parallel().map((base) -> {
//            String url = base + question;
////            return WS.url(url).get();
//        }).findAny();
//        return result.get();
//    }
//
//    private static String getFirstResultCompletableFuture(String question, List<String> engines) {
//        CompletableFuture result = CompletableFuture.anyOf(engines.stream().map((base) -> {
//                    return CompletableFuture.supplyAsync((() -> {
//                        String url = base + question;
////                        return WS.url(url).get();
//                    }));
//                }
//        ).collect(Collectors.toList()).toArray(new CompletableFuture[0]));
//
//        try {
//            return (String) result.get();
//        } catch (InterruptedException | ExecutionException e) {
//            return null;
//        }
//    }

    static class UrlFetcher extends UntypedActor {

        @Override
        public void onReceive(Object message) throws Exception {
            if (message instanceof Message) {
                Message work = (Message) message;
//                String result = WS.url(work.url).get();
                String result = "";
                getSender().tell(new Result(result), getSelf());
            } else {
                unhandled(message);
            }
        }
    }

    static class Message {
        String url;

        Message(String url) {
            this.url = url;
        }
    }

    static class Result {
        String html;

        Result(String html) {
            this.html = html;
        }
    }

}

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.mars</groupId>
    <artifactId>test-concurrency</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>test-concurrency</name>
    <url>http://maven.apache.org</url>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-classic</artifactId>
            <version>1.1.3</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.16.6</version>
        </dependency>
        <dependency>
            <groupId>com.google.guava</groupId>
            <artifactId>guava</artifactId>
            <version>18.0</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>3.8.1</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>com.typesafe.akka</groupId>
            <artifactId>akka-actor_2.10</artifactId>
            <version>2.3.14</version>
        </dependency>
        <dependency>
            <groupId>com.typesafe.play</groupId>
            <artifactId>play-ws_2.10</artifactId>
            <version>2.4.3</version>
        </dependency>
    </dependencies>

    <build>
        <finalName>${project.artifactId}</finalName>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.1</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>