A thread is a thread of execution in a program. The Java
Virtual Machine allows an application to have multiple threads of
execution running concurrently.
Every thread has a priority. Threads with higher priority are
executed in preference to threads with lower priority.
There are two ways to create a new thread of execution. One is to
declare a class to be a subclass of Thread . This
subclass should override the run method of class
Thread . An instance of the subclass can then be
allocated and started. For example, a thread that computes primes
larger than a stated value could be written as follows:
class PrimeThread extends Thread {
long minPrime;
PrimeThread(long minPrime) {
this.minPrime = minPrime;
}
public void run() {
// compute primes larger than minPrime
. . .
}
}
The following code would then create a thread and start it running:
PrimeThread p = new PrimeThread(143);
p.start();
The other way to create a thread is to declare a class that
implements the Runnable interface. That class then
implements the run method. An instance of the class can
then be allocated, passed as an argument when creating
Thread , and started. The same example in this other
style looks like the following:
class PrimeRun implements Runnable {
long minPrime;
PrimeRun(long minPrime) {
this.minPrime = minPrime;
}
public void run() {
// compute primes larger than minPrime
. . .
}
}
The following code would then create a thread and start it running:
PrimeRun p = new PrimeRun(143);
new Thread(p).start();
version: 12/17/01 (CLDC 1.1) See Also: java.lang.Runnable See Also: java.lang.Runtime.exit(int) See Also: java.lang.Thread.run since: JDK1.0, CLDC 1.0 |