multiple threads
hi,
i've got a problem with multiple threads.
i have written a small "traffic simulation" with the following code:
publicvoid start()
{
animator =new Thread(this);// create new thread
light =new Thread("light");
animator.start();// start thread
light.start();
}
/**
* This method is called by the thread that was created in
* the start method. It does the main animation.
*/
publicvoid run()
{
// Remember the starting time
long tm = System.currentTimeMillis();// get time (ms) and store it in tm
while (Thread.currentThread() == animator)
{
// Display the next frame of animation.
if (frame==(200*roadArrangement.size()+50))// if object reaches "end" reset
{
frame =-50;// "reset" frame
}
repaint();// repaint object
//validate();
// Delay depending on how far we are behind.
try
{
tm += delay;// delay
Thread.sleep(Math.max(0, tm - System.currentTimeMillis()));
}
catch (InterruptedException e)// catch exception for thread
{
System.out.println("error in thread interrupt!");
break;
}
frame++;// Advance the frame
setPos();
}
publicvoid paint(Graphics g)
{
Image jct_img = java.awt.Toolkit.getDefaultToolkit().getImage("junction.jpg");
Image rd_img = java.awt.Toolkit.getDefaultToolkit().getImage("street.jpg");
for(int i = 0; i < roadArrangement.size(); i++)
{
int red = 0;
String tempType = roadArrangement.elementAt(i).toString();
char roadType = tempType.charAt(0);
g.setColor(Color.darkGray);
if(roadType =='r')
{
//g.drawImage(rd_img,10+(i*200),100,null);
g.setColor(Color.darkGray);
g.fill3DRect(10+(i*210),100,210,60,true);
}
elseif(roadType =='j')
{
//g.drawImage(jct_img,10+(i*200),30,null);
g.setColor(Color.darkGray);
g.fill3DRect(10+(i*210),100,210,60,true);
g.fill3DRect(85+(i*210),160,60,70,true);
g.fill3DRect(85+(i*210),30,60,70,true);
[b]g.setColor(Color.red);// colour of traffic light[/b]
[b] g.fillOval(10+(i*210)+50,30+100,10,10);// traffic light[/b]
Color clr = g.getColor();
red = clr.getRed();
}
if((frame == (10+(i*210)+50))&&(red==255))
{
System.out.println("STOP");
}
}
}// end of paint instance method
What I would like to do is, that my traffic lights change their colours randomly to red and then after a few second (e.g. 2sec) back to green.
How can I program that, shall I use a second thread?
Thanks in advance.
