Creating and running threads
In java, a thread is represented by an object belonging
to the class java.lang.thread(or to a subclass of this class). The pupose of a
thread object is to execute a single method and to execute it just once. This
metod represents the task to be carried out by the thread.
There are two ways to program a thread.
One is to create a subclass of thread and to define the
method public void run() in the subclass. This run() method defines the task that
will be performed by the thread. For example, here is a simple, class that
defines a thread that does nothing but print a message on standard output:
To use Named Thread, you must of course create an object
belonging to this class. For example,
Named Thread greetings = new Named Thread (“Fred”);
However creating the object does not automatically start
the thread running or cause its run() method to be executed. To do that, you
must call the start() method in the thread object. For example, would be done
with the statement
greetings.start();
The second is to define a class that implements the
interface java.lang.Runnable. The runnable interface defines a single method,
public void run(). Given a runnnable, it is possible to create a thread whose
task is to execute the Runnable’s run() method.
The thread class has a constructor that takes a Runnable
as its parameter when an object that implements the Runnable interface is
passed to that constructor, the run() method of the thread will simply call the
run() method from the Runnable, and calling the thread’s start() method will
create a new thread of control in which Runnable’s run() method is executed.
For example:-
to use this version of class, we would create a
NamedRunnable object and use that object to create an object of type thread:
NamedRunnable greetings = new NamedRunnable(“Fred”);
Thread greetings Thread = new Thread (greetings);
greetingsThread.start();
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