Multithreading and Multiplexing - An Introduction to Network Programming with Java - page 52

In the above program, each of the two threads was carrying out exactly the same
task, which meant that each of them could be created from the same Thread class
and make use of exactly the same run method. In practice, of course, different
threads will normally carry out different tasks. If we want the threads to carry out
actions different from each other's, then we must create a separate class for each
thread (each with its own run method), as shown in the next example.
Example
In this example, we shall again create two threads, but we shall have one thread display
the message 'Hello' fi ve times and the other thread output integers 1-5. For the fi rst
thread, we shall create a class called HelloThread ; for the second, we shall create class
CountThread . Note that it is not the main application class ( ThreadHelloCount , here)
that extends class Thread this time, but each of the two subordinate classes, HelloThread
and CountThread . Each has its own version of the run method.
public class ThreadHelloCount
{
public static void main(String[] args)
{
HelloThread hello = new HelloThread();
CountThread count = new CountThread();
hello.start();
count.start();
}
}
class HelloThread extends Thread
{
public void run()
{
int pause;
for (int i=0; i<5; i++)
{
try
{
System.out.println("Hello!");
//Again, introduce an element
//of randomness…
pause = (int)(Math.random()*3000);
sleep(pause);
}
catch (InterruptedException interruptEx)
{
System.out.println(interruptEx);
}
}