Demo of a JavaFX application which is updated by data streaming in. Created as a solution to https://community.oracle.com/message/12694944#12694944. There are two components: the main application, which consists of a server waiting for messages of the form "speed=<value>", an FXML file, FXML controller, and a main class that creates the server, …

streamingdatafx.DataStreamParser.java

package streamingdatafx;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.logging.Level;
import java.util.logging.Logger;

import javafx.beans.property.DoubleProperty;
import javafx.beans.property.SimpleDoubleProperty;

public class DataStreamParser {

    public static final int DEFAULT_PORT = 1028;

    private final int port;

    private final ExecutorService exec;
    private final Logger logger ;

    private final DoubleProperty speed = new SimpleDoubleProperty(this,
            "speed", 0);

    public final DoubleProperty speedProperty() {
        return this.speed;
    }

    public final double getSpeed() {
        return this.speedProperty().get();
    }

    public final void setSpeed(final double speed) {
        this.speedProperty().set(speed);
    }

    public DataStreamParser(int port) throws IOException {
        this.port = port;

        this.exec = Executors.newCachedThreadPool(runnable -> {
            // run thread as daemon:
            Thread thread = new Thread(runnable);
            thread.setDaemon(true);
            return thread;
        });
        
        this.logger = Logger.getLogger("DataStreamParser");

        try {
            startListening();
        } catch (IOException exc) {
            exc.printStackTrace();
            throw exc;
        }
    }

    public DataStreamParser() throws IOException {
        this(DEFAULT_PORT);
    }

    public void startListening() throws IOException {
        Callable<Void> connectionListener = () -> {
            try (ServerSocket serverSocket = new ServerSocket(port)) {
                logger.info(
                        "Server listening on " + serverSocket.getInetAddress()
                                + ":" + serverSocket.getLocalPort());
                while (true) {
                    logger.info( "Waiting for connection:");
                    Socket socket = serverSocket.accept();
                    logger.info( "Connection accepted from " + socket.getInetAddress());
                    handleConnection(socket);
                }
            } catch (Exception exc) {
                logger.log(Level.SEVERE, "Exception in connection handler", exc);
            }
            return null;
        };
        exec.submit(connectionListener);
    }

    public void shutdown() {
        exec.shutdownNow();
    }

    private void handleConnection(Socket socket) {
        Callable<Void> connectionHandler = () -> {
            try (BufferedReader in = new BufferedReader(new InputStreamReader(
                    socket.getInputStream()))) {
                String line;
                while ((line = in.readLine()) != null) {
                    logger.info("Received: " + line);
                    processLine(line);
                }
                System.out.println("Connection closed from "+socket.getInetAddress());
            }
            return null;
        };
        exec.submit(connectionHandler);
    }

    private void processLine(String line) {
        String[] tokens = line.split("=");
        if ("speed".equals(tokens[0]) && tokens.length == 2) {
            try {
                speed.set(Double.parseDouble(tokens[1]));
            } catch (NumberFormatException exc) {
                logger.log(Level.WARNING, "Non-numeric speed supplied", exc);
            }
        }
    }

}

streamingdatafx.Display.fxml

<?xml version="1.0" encoding="UTF-8"?>
	
<?import javafx.scene.layout.HBox?>
<?import javafx.scene.control.Label?>
<?import javafx.geometry.Insets?>
	
<HBox xmlns:fx="http://javafx.com/fxml/1" spacing="5" 
	alignment="CENTER" fx:controller="streamingdatafx.DisplayController">
	
	<padding>
		<Insets top="10" left="10" right="10" bottom="10"/>
	</padding>
	
	<Label text="Speed:"/>
	<Label fx:id="speedLabel"/>
</HBox>

streamingdatafx.DisplayController.java

package streamingdatafx;

import javafx.fxml.FXML;
import javafx.scene.control.Label;

public class DisplayController {
    @FXML
    private Label speedLabel ;
    
    public void setSpeed(double speed) {
        speedLabel.setText(String.format("%.1f", speed));
    }
}

streamingdatafx.Main.java

package streamingdatafx;
	
import javafx.application.Application;
import javafx.application.Platform;
import javafx.stage.Stage;
import javafx.scene.Scene;
import javafx.scene.layout.HBox;
import javafx.fxml.FXMLLoader;


public class Main extends Application {
    
    private DataStreamParser dataStream ;
    
	@Override
	public void start(Stage primaryStage) {
		try {
		    FXMLLoader loader = new FXMLLoader(getClass().getResource("Display.fxml"));
			HBox root = loader.load();
			DisplayController controller = loader.getController();
			
			dataStream = new DataStreamParser();
			dataStream.speedProperty().addListener((obs, oldSpeed, newSpeed) -> {
			    // update controller on FX Application Thread:
			    Platform.runLater(() -> controller.setSpeed(newSpeed.doubleValue()));
			});
			
			Scene scene = new Scene(root,400,400);
			primaryStage.setScene(scene);
			primaryStage.show();
		} catch(Exception e) {
			e.printStackTrace();
		}
	}
	
	@Override
	public void stop() {
	    if (dataStream != null) {
	        dataStream.shutdown();
	    }
	}
	
	public static void main(String[] args) {
		launch(args);
	}
}

test.Test.fxml

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.scene.layout.HBox?>
<?import javafx.scene.control.TextField?>
<?import javafx.scene.control.Button?>

<HBox xmlns:fx="http://javafx.com/fxml/1" alignment="CENTER" fx:controller="test.TestController">
	<TextField editable="false" fx:id="speedTextField" />
	<Button text="^" onAction="#increaseSpeed"/>
	<Button text="v" onAction="#decreaseSpeed" fx:id="decreaseSpeedButton"/>
</HBox>

test.Test.java

package test;

import java.net.InetAddress;

import streamingdatafx.DataStreamParser;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;

public class Test extends Application {

	@Override
	public void start(Stage primaryStage) throws Exception {
		FXMLLoader loader = new FXMLLoader(getClass().getResource("Test.fxml"));
		Parent root = loader.load();
		TestController controller = loader.getController();
		InetAddress localhost = InetAddress.getLocalHost();
		int port = DataStreamParser.DEFAULT_PORT;
		System.out.println("Connecting to: "+localhost+":"+port);
		controller.connect(localhost, port);
		Scene scene = new Scene(root, 350, 75);
		primaryStage.setScene(scene);
		primaryStage.show();
	}

	public static void main(String[] args) {
		launch(args);
	}
}

test.TestController.java

package test;

import java.io.IOException;
import java.io.PrintWriter;
import java.net.InetAddress;
import java.net.Socket;

import javafx.beans.property.IntegerProperty;
import javafx.beans.property.SimpleIntegerProperty;
import javafx.fxml.FXML;
import javafx.scene.control.Button;
import javafx.scene.control.TextField;

public class TestController {
    @FXML
    private Button decreaseSpeedButton ;
    
    @FXML
    private TextField speedTextField ;
    
    private Socket socket ;
    private PrintWriter out ;
    
    private IntegerProperty speed = new SimpleIntegerProperty(55);
    
    
    public void initialize() {
        speedTextField.textProperty().bind(speed.asString());
        
        speed.addListener((obs, oldSpeed, newSpeed) -> {
            String message = "speed="+speed.get()+"\n";
            if (out != null) {
                System.out.println(message);
                out.println(message);
                out.flush();
            }
        });
    }
    
    @FXML
    private void increaseSpeed() {
        speed.set(speed.get()+1);
    }
    
    @FXML
    private void decreaseSpeed() {
        speed.set(Math.max(0, speed.get()-1));
    }
    
    public void connect(InetAddress address, int port) throws IOException {
        socket = new Socket(address, port);
        out = new PrintWriter(socket.getOutputStream());
        System.out.println("Connected");
    }
    
    public void shutdown() throws IOException {
        if (out != null) {
            out.close();
        }
        if (socket != null && socket.isConnected()) {
            socket.close();
        }
    }
}