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jumar/FirstLineSequentialVsParallelService.java

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Last active August 29, 2015 14:08
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  1. @jewelsea jewelsea created this gist Feb 13, 2013.
    166 changes: 166 additions & 0 deletions FirstLineSequentialVsParallelService.java
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,166 @@
    import java.io.*;
    import java.net.URL;
    import java.util.concurrent.*;
    import java.util.concurrent.atomic.AtomicInteger;
    import javafx.application.Application;
    import javafx.beans.property.*;
    import javafx.concurrent.*;
    import javafx.event.EventHandler;
    import javafx.scene.*;
    import javafx.scene.control.*;
    import javafx.scene.layout.*;
    import javafx.stage.Stage;

    public class FirstLineSequentialVsParallelService extends Application {
    private static final String[] URLs = {
    "http://www.google.com",
    "http://www.yahoo.com",
    "http://www.microsoft.com",
    "http://www.oracle.com"
    };

    private ExecutorService sequentialFirstLineExecutor;
    private ExecutorService parallelFirstLineExecutor;

    @Override public void init() throws Exception {
    sequentialFirstLineExecutor = Executors.newFixedThreadPool(
    1,
    new FirstLineThreadFactory("sequential")
    );

    parallelFirstLineExecutor = Executors.newFixedThreadPool(
    URLs.length,
    new FirstLineThreadFactory("parallel")
    );
    }

    @Override
    public void stop() throws Exception {
    parallelFirstLineExecutor.shutdown();
    parallelFirstLineExecutor.awaitTermination(3, TimeUnit.SECONDS);

    sequentialFirstLineExecutor.shutdown();
    sequentialFirstLineExecutor.awaitTermination(3, TimeUnit.SECONDS);
    }

    public static void main(String[] args) { launch(args); }
    @Override public void start(Stage stage) throws Exception {
    final VBox messages = new VBox();
    messages.setStyle("-fx-background-color: cornsilk; -fx-padding: 10;");

    messages.getChildren().addAll(
    new Label("Parallel Execution"),
    new Label("------------------"),
    new Label()
    );
    fetchFirstLines(messages, parallelFirstLineExecutor);

    messages.getChildren().addAll(
    new Label("Sequential Execution"),
    new Label("--------------------"),
    new Label()
    );
    fetchFirstLines(messages, sequentialFirstLineExecutor);

    messages.setStyle("-fx-font-family: monospace");

    stage.setScene(new Scene(messages, 600, 800));
    stage.show();
    }

    private void fetchFirstLines(final VBox monitoredLabels, ExecutorService executorService) {
    for (final String url: URLs) {
    final FirstLineService service = new FirstLineService();
    service.setExecutor(executorService);
    service.setUrl(url);

    final ProgressMonitoredLabel monitoredLabel = new ProgressMonitoredLabel(url);
    monitoredLabels.getChildren().add(monitoredLabel);
    monitoredLabel.progress.progressProperty().bind(service.progressProperty());

    service.setOnSucceeded(new EventHandler<WorkerStateEvent>() {
    @Override public void handle(WorkerStateEvent t) {
    monitoredLabel.addStrings(
    service.getMessage(),
    service.getValue()
    );
    }
    });
    service.start();
    }
    }

    public class ProgressMonitoredLabel extends HBox {
    final ProgressBar progress;
    final VBox labels;

    public ProgressMonitoredLabel(String initialString) {
    super(20);

    progress = new ProgressBar();
    labels = new VBox();
    labels.getChildren().addAll(new Label(initialString), new Label());

    progress.setPrefWidth(100);
    progress.setMinWidth(ProgressBar.USE_PREF_SIZE);
    HBox.setHgrow(labels, Priority.ALWAYS);
    setMinHeight(80);

    getChildren().addAll(progress, labels);
    }

    public void addStrings(String... strings) {
    for (String string: strings) {
    labels.getChildren().add(
    labels.getChildren().size() - 1,
    new Label(string)
    );
    }
    }
    }

    public static class FirstLineService extends Service<String> {
    private StringProperty url = new SimpleStringProperty(this, "url");
    public final void setUrl(String value) { url.set(value); }
    public final String getUrl() { return url.get(); }
    public final StringProperty urlProperty() { return url; }
    protected Task createTask() {
    final String _url = getUrl();
    return new Task<String>() {
    protected String call() throws Exception {
    updateMessage("Called on thread: " + Thread.currentThread().getName());
    URL u = new URL(_url);
    BufferedReader in = new BufferedReader(
    new InputStreamReader(u.openStream()));
    String result = in.readLine();
    in.close();

    // pause just so that it really takes some time to run the task
    // so that parallel execution behaviour can be observed.
    for (int i = 0; i < 100; i++) {
    updateProgress(i, 100);
    Thread.sleep(50);
    }

    return result;
    }
    };
    }
    }

    static class FirstLineThreadFactory implements ThreadFactory {
    static final AtomicInteger poolNumber = new AtomicInteger(1);
    private final String type;

    public FirstLineThreadFactory(String type) {
    this.type = type;
    }

    @Override public Thread newThread(Runnable runnable) {
    Thread thread = new Thread(runnable, "LineService-" + poolNumber.getAndIncrement() + "-thread-" + type);
    thread.setDaemon(true);

    return thread;
    }
    }
    }