Break java loop

Question

My project in Java is a lighthouse control with Arduino. Up to there everything right. However I made a function in which the leds is automatic in a loop after a RadionButton be selected. My problem is that when I select the RadionButton mine JFrame freeze and don’t let me take out the selection of RadionButton.

In other words, selecting the button causes an active loop. The idea would be to uncheck the button, stop the loop.

Follows my code.

Here is where the button will be selected and send the command to the function:

        if ( teste.isSelected() ) {
        try {
            utiArduino.enviarDados( "automatico" );
        } catch (InterruptedException | IOException ex) {
            Logger.getLogger(Jframe_farol.class.getName()).log(Level.SEVERE, null, ex);
        }
    } else {
        try {
            utiArduino.enviarDados( "DesligaAuto" );
        } catch (InterruptedException | IOException ex) {
            Logger.getLogger(Jframe_farol.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

Here is the function of the loop:

  public void enviarDados(String status) throws InterruptedException, IOException{
   int i = 8;

    if ( "automatico".equals(status) ) { // caso do automatico   
        while ( true ) {
            output.write(i);
            Thread.sleep(1000);
            i++;
            if ( i > 10 ){
                i = 8;
            }
        }
    }
} 

Answer 1

AWT and Swing have a thread that manages their operation, it is called Event Dispatch Thread - EDT. As she is a unique thread, if you make her fall into a while (true) and/or in a Thread.sleep(1000), the graphical interface will be frozen.

So the solution is to move these things to a distinct thread. Try doing so in your class utiArduino:

private volatile String ultimoStatus;
private volatile Thread threadArduino;

public void enviarDados(String status) {
   ultimoStatus = status;
   if (threadArduino == null) {
       threadArduino = new Thread(this::iniciarEnvioArduino);
       threadArduino.start();
   }
}

private void envioArduino() {
    int i = 8;
    try {
        while (Thread.currentThread() == threadArduino) {
            if ("automatico".equals(ultimoStatus)) { // caso do automatico   
                output.write(i);
                Thread.sleep(1000);
                i++;
                if (i > 10) i = 8;
            }
        }
    } catch (IOException e) {
        e.printStackTrace();
    } catch (InterruptedException e) {
        // Não faz nada e deixa a thread morrer.
    }
}

public void parar() {
    if (threadArduino != null) {
        Thread t = threadArduino;
        threadArduino = null;
        t.interrupt();
    }
}

Your button selection looks like this:

utiArduino.enviarDados(teste.isSelected() ? "automatico" : "DesligaAuto");

In his subclass of JFrame (who assumes to be the one with the reference utiArduino), put this too:

@Override
public void dispose() {
    super.dispose();
    utiArduino.parar();
}

For more information on EDT, read in that my other answer also.