CODEWITHSUNDEEP
java
user2021373
user2021373

Reputation: 27

Timer and timerTask small issue

i am a noob at java. This is my first time use timer and timerTask class in java.

Purpose of my app:

It is multi client app that implemented with MySQL. My app is to read my database data repeatly. If database updated, then i want every client's panel updated as well. so I assume i need a timer class that can automatically perform repeating query that read my database and then make some change on the component of the client side.

Problem:

I look thought some tutorial and i found this way to do it. Since this.updateTableStatus() method is in my Table class, how can i use that method in my MyTimer(timerTask) class.

public class Table extends javax.swing.JFrame {

    public Table() {
        initComponents();
        MyTimer myTime = new MyTimer();

    }
    public void updateTableStatus(){
        // this is where I refresh my table status which is reading database data and make some change.
    }

    class MyTimer extends TimerTask{
        public MyTimer() {
            Timer timer = new Timer();
            timer.scheduleAtFixedRate(this, new java.util.Date(), 1000);
        }
        public void run(){

            this.updateTableStatus();   // this is not working!!!, because they r not in the same class.  I need help to solve this problem.
        }
    }
}

Help me out guys. thank you so much.

Upvotes: 0

Views: 108

Answers (2)

gkalpak
gkalpak

Reputation: 48212

this.updateTableStatus(); tries to reference MyTimer's updateTableStatus() method (but there is no such method). To reference Table's updateTableStatus() method, you can change it to 

Table.this.updateTableStatus();

NOTE:
Seriously, I believe that checking the DB every second from each client to see if anything has changed is a horribly bad app design. I suggest you post a new question, explaining your current architecture and requirements, and asking advice about how to watch for DB changes efficiently.

Upvotes: 0

camickr
camickr

Reputation: 324108

It is probably better to use a Swing Worker and then publish the results when the data changes. This way you don't block the EDT while doing your database query.

If you are going to use a TimerTask, then you need to wrap any updates to the TableModel in a SwingUtilities.invokeLater().

Upvotes: 1

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