稍后运行不适用JavaFX

Question

我在做一个Platform.Runlater来更新一个TextField。在这里您可以看到代码：

public class FXMLDocumentController implements Initializable {

    @FXML
    private TextField carlos;
    RXTX main = new RXTX();

    public void Test(){
    Platform.runLater(new Runnable() {
                    @Override public void run() {
                        carlos.setText("Test");    
                  }
                });

    }



    @Override
    public void initialize(URL url, ResourceBundle rb) {
        main.initialize();
        Thread t=new Thread() {
            public void run() {
                //the following line will keep this app alive for 1000 seconds,
                //waiting for events to occur and responding to them (printing incoming messages to console).
                try {Thread.sleep(1000000);} catch (InterruptedException ie) {}
            }
        };
        t.start();
        System.out.println("Started");
    }    

}

public class RXTX implements SerialPortEventListener{


    private String Temperature;

        SerialPort serialPort;
        /** The port we're normally going to use. */
    private static final String PORT_NAMES[] = { 
            "COM4" // Windows
    };
    /**
    * A BufferedReader which will be fed by a InputStreamReader 
    * converting the bytes into characters 
    * making the displayed results codepage independent
    */
    private BufferedReader input;
    /** The output stream to the port */
    private OutputStream output;
    /** Milliseconds to block while waiting for port open */
    private static final int TIME_OUT = 2000;
    /** Default bits per second for COM port. */
    private static final int DATA_RATE = 9600;

    public void initialize() {
        CommPortIdentifier portId = null;
        Enumeration portEnum = CommPortIdentifier.getPortIdentifiers();

        //First, Find an instance of serial port as set in PORT_NAMES.
        while (portEnum.hasMoreElements()) {
            CommPortIdentifier currPortId = (CommPortIdentifier) portEnum.nextElement();
            for (String portName : PORT_NAMES) {
                if (currPortId.getName().equals(portName)) {
                    portId = currPortId;
                    break;
                }
            }
        }
        if (portId == null) {
            System.out.println("Could not find COM port.");
            return;
        }

        try {
            // open serial port, and use class name for the appName.
            serialPort = (SerialPort) portId.open(this.getClass().getName(),
                    TIME_OUT);

            // set port parameters
            serialPort.setSerialPortParams(DATA_RATE,
                    SerialPort.DATABITS_8,
                    SerialPort.STOPBITS_1,
                    SerialPort.PARITY_NONE);

            // open the streams
            input = new BufferedReader(new InputStreamReader(serialPort.getInputStream()));
            output = serialPort.getOutputStream();

            // add event listeners
            serialPort.addEventListener(this);
            serialPort.notifyOnDataAvailable(true);
        } catch (Exception e) {
            System.err.println(e.toString());
        }
    }

    /**
     * This should be called when you stop using the port.
     * This will prevent port locking on platforms like Linux.
     */
    public synchronized void close() {
        if (serialPort != null) {
            serialPort.removeEventListener();
            serialPort.close();
        }
    }

    /**
     * Handle an event on the serial port. Read the data and print it.
     */
    public synchronized void serialEvent(SerialPortEvent oEvent) {
        if (oEvent.getEventType() == SerialPortEvent.DATA_AVAILABLE) {
            try {
                String inputLine=input.readLine();
                System.out.println(inputLine);
                                GetData(inputLine);
            } catch (Exception e) {
                System.err.println(e.toString());
            }
        }
        // Ignore all the other eventTypes, but you should consider the other ones.
    }

        @FXML
    private void GetData(String Data) {

            if(Data.contains("Temperature")){
                FXMLDocumentController main = new FXMLDocumentController();
                main.Test();
            }

        }
}

在OpenPilot.fxmlDocumentController$1.run(fxmlDocumentController.java:35)在com.sun.javafx.application.platformImpl$4$1.run(platformImpl.java:182)在com.sun.javafx.application.platformImpl$4$1.run(platformImpl.java:179)在java.security.accessController.doprivileged（本机方法）在在com.sun.glass.ui.win.winapplication._runloop（本机方法）在com.sun.glass.ui.win.winapplication.access$100(winapplication.java:17)在com.sun.glass.ui.win.winapplication.3$1.run(winapplication.java:67)在java.lang.thread.run(thread.java:744)

Answer 1

不要使用new创建FXML控制器，而是使用fxmlloader.load（）。

在您的特殊情况下，最好使用platform.runlater（）调用JavaFX应用程序线程上的load（）。

FXMLLoader创建@fxml注释节点的实例。因此，除非使用加载器，否则将永远不会创建@fxml节点。因此，在本例中，您的“Carlos”TextField是null，因为没有任何东西创建这样的TextField，导致您的NullPointerException。

您的代码中可能还有很多其他错误。

我建议在处理与串行端口通信的多线程应用程序之前，先花更多的时间编写基本的单线程JavaFX应用程序。