Special Effects and Game Development
in Java(TM) - The run() method
by Anibal Wainstein
3.0.2 The run() method
In contrast to the start() and stop() methods, the run()
method will always be different from applet to applet. This
methods is always called by your self-created thread.
This means that you have a thread that works with the applets
other methods (the main thread) and a thread that works with
the run() method (your own thread that you initialize in the
start() method). By "holding" the thread in the
run() method with a loop, you can exploit it to do work that
will not hang the JVM:
public void run()
{
while (true)
{
}
}
In the example above we are holding the thread within the loop
forever (or until the applet's stop() method is called). The
problem with the applet that we made in chapter 2.0.4,
was that it was overwritten by other status messages from the
web browser. Threads can help us here, because they constantly
manage to update a message on the status window, and by doing
so, overwriting other web browser messages. Let us rewrite the
applet: import java.applet.*;
import java.awt.*;
public class threadtest extends Applet implements Runnable {
public Thread animationthread = null;
public void start()
{
if (animationthread == null)
{
animationthread = new Thread(this,"animationthread");
animationthread.start();
}
}
public void stop()
{
if ((animationthread != null) && animationthread.isAlive())
animationthread.stop();
animationthread = null;
}
public void run()
{
while (true)
{
showStatus("Hello Sweden!");
}
}
}
Compile the applet and run it. You can also click
here to see it. You will notice that the message "Hello
Sweden!" is being displayed in the status window of your
browser.
Next Page >>
|
 | |
|
