Question

I have a question relating to the timer function. I have managed to find the cause of my problem, but I’m not sure on how to address it. I will give you an overview of my function. It will first execute the cost() function, with a background thread working. However, what I realize was that my cost() function failed to load right at the beginning. Secondly, it’s program to run every 60 secs which it failed as well. I check my code for my cost() function and it works fine if I call it down without the timer function. Could it be my Opencsv() function? The question is it due to constraint of the timer function or is there ways to address this issue?

public static void main(String[] args)  {
  launch(EVschedulerApp.class, args);

  Timer timer = new Timer();
  // timer.scheduleAtFixedRate(new Cost(), 10*1000, 10*1000);

  timer.scheduleAtFixedRate(new Cost() {

      @Override
        public void run() {
        new Thread(new Runnable() {
            public void run() {
              File file = new File("D:/test.csv");
              if(file != null){
                try {
                  Opencsv csv = new Opencsv();

                  csv.Csvreader();
                } catch (IOException ex) {
                  Logger.getLogger(EVschedulerApp.class.getName()).log(Level.SEVERE, null, ex);
                }

              }
              else {

                try {
                  Thread.sleep(1000);
                } catch (InterruptedException e) {}
              }
            }
          }).start();
      }

Opencsv class file:

public class Opencsv {

  public void Csvreader() throws IOException {
    try {
      // TODO code application logic here

      CSVReader reader = new CSVReader(new FileReader("D:/Test.csv"));

      String [] nextLine;
      while ((nextLine = reader.readNext()) != null) {
        // nextLine[] is an array of values from the line
        System.out.println(nextLine[0] + " " + nextLine[1]+ " " + nextLine[2]+ " " + nextLine[3]);
      }
    } catch (FileNotFoundException ex) {
      Logger.getLogger(Opencsv.class.getName()).log(Level.SEVERE, null, ex);
    }

  }
}

Cost Class:

public class Cost extends TimerTask{

public void run() {
Calendar rightNow = Calendar.getInstance();
Integer hour = rightNow.get(Calendar.HOUR_OF_DAY);
if (hour==23 ) {
try {
  URL tariff = new URL("http://www.******.downloadRealtime=true");
            ReadableByteChannel tar = Channels.newChannel(Test.openStream());
            FileOutputStream fos = new FileOutputStream("Test.csv");
            fos.getChannel().transferFrom(tar, 0, 1<<24);

 } catch (IOException ex) {
            Logger.getLogger(Cost.class.getName()).log(Level.SEVERE, null, ex);
 } 
  }




  else {

  }
  }

Answer 1

I think your bug is that you never call Cost‘s run() method, you are not just overriding it, you are hiding it. Try something like this:

timer.scheduleAtFixedRate(new Cost() {
  @Override
    public void run() {

    super.run();  //Added this call to Cost's original method.

    new Thread(new Runnable() {
        public void run() {
          //your code still here
        }
      }).start();
  }

Although, as others point out, you should look into the Executor Service.