Example usage for java.util.concurrent Executors newFixedThreadPool

List of usage examples for java.util.concurrent Executors newFixedThreadPool

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Introduction

In this page you can find the example usage for java.util.concurrent Executors newFixedThreadPool.

Prototype

public static ExecutorService newFixedThreadPool(int nThreads)

Source Link

Document

Creates a thread pool that reuses a fixed number of threads operating off a shared unbounded queue.

Usage

From source file:SimpExec.java

public static void main(String args[]) {
    CountDownLatch cdl = new CountDownLatch(5);
    CountDownLatch cdl2 = new CountDownLatch(5);
    CountDownLatch cdl3 = new CountDownLatch(5);
    CountDownLatch cdl4 = new CountDownLatch(5);
    ExecutorService es = Executors.newFixedThreadPool(2);

    es.execute(new MyThread(cdl, "A"));
    es.execute(new MyThread(cdl2, "B"));
    es.execute(new MyThread(cdl3, "C"));
    es.execute(new MyThread(cdl4, "D"));

    try {//from  ww  w. j  a v  a  2 s . c  om
        cdl.await();
        cdl2.await();
        cdl3.await();
        cdl4.await();
    } catch (InterruptedException exc) {
        System.out.println(exc);
    }

    es.shutdown();
}

From source file:Main.java

public static void main(final String[] args) throws Exception {
    Random RND = new Random();
    ExecutorService es = Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors());
    List<Future<String>> results = new ArrayList<>(10);
    for (int i = 0; i < 10; i++) {
        results.add(es.submit(new TimeSliceTask(RND.nextInt(10), TimeUnit.SECONDS)));
    }/*ww  w  .j  a v a2  s.c o m*/
    es.shutdown();
    while (!results.isEmpty()) {
        Iterator<Future<String>> i = results.iterator();
        while (i.hasNext()) {
            Future<String> f = i.next();
            if (f.isDone()) {
                System.out.println(f.get());
                i.remove();
            }
        }
    }
}

From source file:WordLengthCallable.java

public static void main(String[] args) throws Exception {
    int THREAD_COUNT = 4;
    ExecutorService execService = Executors.newFixedThreadPool(THREAD_COUNT);
    CompletionService<Integer> completionService = new ExecutorCompletionService<>(execService);

    for (int i = 0; i < THREAD_COUNT; i++) {
        completionService.submit(new WordLengthCallable());
    }/*from  ww  w .  j  a  va2s  .c  om*/
    execService.shutdown();
    while (!execService.isTerminated()) {
        int result = completionService.take().get().intValue();
        System.out.println("Result is: " + result);
    }
    Thread.sleep(1000);
    System.out.println("done!");
}

From source file:kymr.github.io.future.LoadTest.java

public static void main(String[] args) throws InterruptedException {
    ExecutorService es = Executors.newFixedThreadPool(100);

    RestTemplate rt = new RestTemplate();
    String url = "http://localhost:8080/dr";

    StopWatch main = new StopWatch();
    main.start();//from  w w  w  .j  av a2  s.  c o m

    for (int i = 0; i < 100; i++) {
        es.execute(() -> {
            int idx = counter.addAndGet(1);
            log.info("Thread {}", idx);

            StopWatch sw = new StopWatch();
            sw.start();

            rt.getForObject(url, String.class);

            sw.stop();
            log.info("Elapsed: {} -> {}", idx, sw.getTotalTimeSeconds());
        });
    }

    es.shutdown();
    es.awaitTermination(100, TimeUnit.SECONDS);

    main.stop();
    log.info("Total: {}", main.getTotalTimeSeconds());
}

From source file:CallableTask.java

public static void main(String[] args) throws Exception {
    // Get an executor with three threads in its thread pool
    ExecutorService exec = Executors.newFixedThreadPool(3);
    CallableTask task = new CallableTask(1);
    // Submit the callable task to executor
    Future<Integer> submittedTask = exec.submit(task);

    Integer result = submittedTask.get();
    System.out.println("Task's total  sleep time: " + result + "  seconds");
    exec.shutdown();/* ww w. jav  a  2 s  .c o m*/
}

From source file:RunnableTask.java

public static void main(String[] args) {
    final int THREAD_COUNT = 3;
    final int LOOP_COUNT = 3;
    final int TASK_COUNT = 5;

    // Get an executor with three threads in its thread pool
    ExecutorService exec = Executors.newFixedThreadPool(THREAD_COUNT);

    // Create five tasks and submit them to the executor
    for (int i = 1; i <= TASK_COUNT; i++) {
        RunnableTask task = new RunnableTask(i, LOOP_COUNT);
        exec.submit(task);//  w w  w  .j  a  va 2 s.  c o m
    }
    exec.shutdown();
}

From source file:com.apress.prospringintegration.customadapters.inbound.eventdriven.fsmon.DirectoryMonitorClient.java

public static void main(String[] args) throws Throwable {
    File[] files = { new File(new File(SystemUtils.getUserHome(), "Desktop"), "test2"),
            new File(new File(SystemUtils.getUserHome(), "Desktop"), "test1") };

    Executor ex = Executors.newFixedThreadPool(10);

    final LinuxInotifyDirectoryMonitor monitor = new LinuxInotifyDirectoryMonitor();
    monitor.setExecutor(ex);//from  ww  w.  j a v  a  2s. c o m
    monitor.afterPropertiesSet();

    final DirectoryMonitor.FileAddedListener fileAddedListener = new DirectoryMonitor.FileAddedListener() {
        @Override
        public void fileAdded(File dir, String fn) {
            System.out
                    .println("A new file in " + dir.getAbsolutePath() + " called " + fn + " has been noticed");
        }
    };

    for (File f : files) {
        monitor.monitor(f, fileAddedListener);
    }
}

From source file:example.rhino.DynamicScopesWithHandlebars.java

public static void main(String[] args) {
    Context cx = Context.enter();
    try {//from   ww  w .ja  v  a 2 s .c om
        String source = handlebars();
        Script script = cx.compileString(source, "handlebars", 1, null);

        System.out.println("Running the script in a single thread");
        runScripts(cx, script, Executors.newSingleThreadExecutor());

        int nThreads = Runtime.getRuntime().availableProcessors();
        System.out.format("Running the script in %d thread\n", nThreads);

        runScripts(cx, script, Executors.newFixedThreadPool(nThreads));

    } catch (IOException e) {
        System.err.println("No handlebars file found");
    } finally {
        Context.exit();
    }
}

From source file:MyResult.java

public static void main(String[] args) throws Exception {
    // Get an executor with three threads in its thread pool
    ExecutorService exec = Executors.newFixedThreadPool(3);

    // Completed task returns an object of the TaskResult class
    ExecutorCompletionService<MyResult> completionService = new ExecutorCompletionService<>(exec);
    for (int i = 1; i <= 5; i++) {
        SleepingTask task = new SleepingTask(i, 3);
        completionService.submit(task);//from   w  w  w.  ja v a2  s .  c o m
    }
    for (int i = 1; i <= 5; i++) {
        Future<MyResult> completedTask = completionService.take();
        MyResult result = completedTask.get();
        System.out.println("Completed a  task - " + result);
    }
    exec.shutdown();
}

From source file:locking.LockingExample.java

public static void main(String[] args) throws Exception {
    // all of the useful sample code is in ExampleClientThatLocks.java

    // FakeLimitedResource simulates some external resource that can only be access by one process at a time
    final FakeLimitedResource resource = new FakeLimitedResource();

    ExecutorService service = Executors.newFixedThreadPool(QTY);
    final TestingServer server = new TestingServer();
    try {//from   ww w .j a v a  2 s.  c  o  m
        for (int i = 0; i < QTY; ++i) {
            final int index = i;
            Callable<Void> task = new Callable<Void>() {
                @Override
                public Void call() throws Exception {
                    CuratorFramework client = CuratorFrameworkFactory.newClient(server.getConnectString(),
                            new ExponentialBackoffRetry(1000, 3));
                    try {
                        client.start();

                        ExampleClientThatLocks example = new ExampleClientThatLocks(client, PATH, resource,
                                "Client " + index);
                        for (int j = 0; j < REPETITIONS; ++j) {
                            example.doWork(10, TimeUnit.SECONDS);
                        }
                    } catch (Throwable e) {
                        e.printStackTrace();
                    } finally {
                        IOUtils.closeQuietly(client);
                    }
                    return null;
                }
            };
            service.submit(task);
        }

        service.shutdown();
        service.awaitTermination(10, TimeUnit.MINUTES);
    } finally {
        IOUtils.closeQuietly(server);
    }
}