Java Reference
In-Depth Information
Because garbage collection runs sporadically in the background, it is not trivial to demon-
strate it. However, one way it can be done is through the use of the
finalize( )
method.
Recall that
finalize( )
is called when an object is about to be recycled. As explained, objects
are not necessarily recycled as soon as they are no longer needed. Instead, the garbage col-
lector waits until it can perform its collection efficiently, usually when there are many un-
used objects. Thus, to demonstrate garbage collection via the
finalize( )
method, you often
need to create and destroy a large number of objects—and this is precisely what you will
do in this project.
1.
Create a new file called
Finalize.java.
2.
Create the
FDemo
class shown here:
The constructor sets the instance variable
x
to a known value. In this example,
x
is
used as an object ID. The
finalize( )
method displays the value of
x
when an object is
recycled. Of special interest is
generator( )
. This method creates and then promptly
discards an
FDemo
object. You will see how this is used in the next step.
3.
Create the
Finalize
class, shown here: