How can I update the JProgressBar.setValue(int) from another thread? My secondary goal is do it in the least amount of classes possible.

Here is the code I have right now:

**Part of the main class....**
pp.addActionListener(
                new ActionListener(){
                    public void actionPerformed(ActionEvent event)
                    {
                            new Thread(new Task(sd.getValue())).start(); 
                    }
                });

public class Task implements Runnable{
int val;
public Task(int value){
    this.val = value;
}
@Override
public void run() {
    for (int i=0; i<=value; i++){ //Progressively increment variable i 
        pbar.setValue(i); //Set value 
        pbar.repaint(); //Refresh graphics 
        try{Thread.sleep(50);} //Sleep 50 milliseconds 
        catch (InterruptedException err){} 
    } 
    }
}

pp is a JButton and starts the new thread when the JButton is clicked.

pbar is the JProgressBar object from the Main class.

How can I update its value?(progress)

The code above in run() cannot see the pbar.