Sharing variable between two threads.

[Joseph Cho]

I'm trying to have one thread keep track of the time while the main thread does the work.. For some reason the thread is not getting the updated variable, how do I get this to work? I tried using a static variable but it's not working..

Here is the code:

package QuestionProgram;


import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.io.File;
import java.io.FileNotFoundException;
import java.util.ArrayList;
import java.util.Scanner;

import javax.swing.JPanel;

public class QuestionPanel extends JPanel implements Runnable
{
	private TimerPanel timerPanel;
	private AnswerPanel answerPanel;
	private Thread thread;
	
	public ArrayList<Question> questions =  new ArrayList<Question>();
	int arrayIndex = 0;
	
	static boolean timeIsUp = false;
    static boolean testFinished = false;
	boolean firstTime = true;
	boolean firstTimeFill = true;
	
	public QuestionPanel() 
	{
		
		this.setBackground(Color.green);
	}
	
	public void go()
	{
		thread = new Thread(this);
		thread.start();
		
		if(firstTimeFill)
		{
		 fileToArray();
		}
		firstTime = false;
		repaint();
	}

    void setObjects(AnswerPanel answerPanel, TimerPanel timerPanel)
    {
  	  this.answerPanel = answerPanel;
  	  this.timerPanel = timerPanel;
    }
	
	public void run() 
	{
		
		System.out.println("inside run firstTimeFill= " + firstTimeFill);
		
		
		 while ((!timeIsUp) && (!testFinished))
		   {
			// timeIsUp = this.timeIsUp;
			// testFinished = this.testFinished;
			 System.out.println("enters thread, testFinsihed=" + testFinished);
			 System.out.println("enters thread, timeIsUp=" + timeIsUp);
	         try
			 {
			   // Thread.sleep(1000);
			    Thread.sleep(1000);
			 }catch(InterruptedException e)
			 { 
			    e.printStackTrace();}
			    //currentTime=System.currentTimeMillis();
		   }
		 timerPanel.stopTimer();
		System.out.println("test is over");
    }
	
	void fileToArray()
	{
		// Location of file to read
		   firstTimeFill = false;
		   File file = new File("quiz.txt");
		   String line = "test";
		   String answer = "test";
		   
		   try 
		   {
		     Scanner scanner = new Scanner(file);
		     while (scanner.hasNextLine()) 
		     {
		       line = scanner.nextLine(); //get line
		       line = line.trim();
		       String check = line.substring(line.length() - 3); //store last three characters to check for jpg
		       check = check.trim(); //trim any whitespace
		       if(scanner.hasNextLine())
		       {
		    	   answer = scanner.nextLine();

		       }
		       
		       
		       if(check.equals("jpg"))
		       {
		    	  questions.add(new ImageQuestion(line, answer, this));
		       }
		       else
		       {
		    	   questions.add(new TextQuestion(line, answer, this));
		       }
		      }//end while 
		        

		       scanner.close();
		     }//end try 
		     catch (FileNotFoundException e) 
		     {
		       e.printStackTrace();
		     }//end catch
	}
	
	public String getTotalPts()
	{
		int total = 0;
		for(int i=0; i<questions.size(); i++)
		{
			total = total + questions.get(i).score;
		}
		
		return Integer.toString(total);
	}
	
	@SuppressWarnings("deprecation")
	void reset()
	{
		arrayIndex = 0;
		answerPanel.counter=0;
		firstTime = true;
		timeIsUp = false;
		testFinished = false;
		//thread.stop();
	}
	
	
	public void paintComponent(Graphics g)
	{
		super.paintComponent(g);
		
		if(firstTime)
			return;
		

		System.out.println(arrayIndex);
		System.out.println(questions.size());
		
        if(arrayIndex < questions.size())
        {
        
		  Dimension d = new Dimension();
		  d.height = 0;
		  d.width = 0;
		  System.out.println(arrayIndex);
		  questions.get(arrayIndex).draw(g, d);
        }
        else
        {
        	testFinished = true;
        	timerPanel.stopTimer();
        	g.drawString("Test Complete!", 12, 20);
        	g.drawString("Your Results are:", 12, 40);
        	
        	g.drawString(getTotalPts(), 12, 60);
        	
        	reset();
        }
	}
	
	
}

[Rakesh K. Cherukuri]

Duplicate of http://www.coderanch.com/t/597439/threads/java/Sharing-variable-between-two-threads

The other one already has responses