Java Reference
In-Depth Information
threadingscenarios.Also,youmighthavetoanalyzesomeoneelse'ssourcecodethat
depends on Threading.
Runnable and Thread
Java provides the
Runnable
interface to identify those objects that supply code for
threadstoexecuteviathisinterface'ssolitary
void run()
method—athreadreceives
noargumentsandreturnsnovalue.Classesimplement
Runnable
tosupplythiscode,
and one of these classes is
Thread
.
Thread
providesaconsistentinterfacetotheunderlyingoperatingsystem'sthread-
ing architecture. (The operating system is typically responsible for creating and man-
agingthreads.)
Thread
makesitpossibletoassociatecodewiththreads,aswellasstart
and manage those threads. Each
Thread
instance associates with a single thread.
Thread
declaresseveralconstructorsforinitializing
Thread
objects.Someofthese
constructorstake
Runnable
arguments:youcansupplycodetorunwithouthavingto
extend
Thread
. Other constructors do not take
Runnable
arguments: you must ex-
tend
Thread
and override its
run()
method to supply the code to run.
Forexample,
Thread(Runnable runnable)
initializesanew
Thread
object
to the specified
runnable
whose code is to be executed. In contrast,
Thread()
doesnotinitialize
Thread
toa
Runnable
argument.Instead,your
Thread
subclass
providesaconstructorthatcalls
Thread()
,andthesubclassalsooverrides
Thread
's
run()
method.
Intheabsenceofanexplicitnameargument,eachconstructorassignsauniquedefault
name (starting with
Thread-
)to the
Thread
object. Names make it possible to dif-
ferentiate threads. In contrast to the previous two constructors, which choose default
names,
Thread(String threadName)
lets you specify your own thread name.
Thread
also declares methods for starting and managing threads.
Table 4-7
de-
scribes many of the more useful methods.
