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The
Applet class provides a framework for applet execution,
defining methods that the system calls when milestones occur.
Milestones are major events in an applet's life cycle.
Most applets override some or all of these methods to respond
appropriately to milestones.
init Method
The init method is useful for one-time initialization
that doesn't take very long. The init method typically
contains the code that you would normally put into a constructor.
The reason applets don't usually have constructors is that they aren't
guaranteed to have a full environment until their init method is called.
Keep the init method short so that your applet can load quickly.
start Method
Every applet that performs tasks after initialization
(except in direct response to user actions)
must override the start method.
The start method starts the execution of the applet.
It is good practice to return quickly from the start method.
If you need to perform computationally intensive operations it might be
better to start a new thread
for this purpose.
stop Method
Most applets that override the start should also override the
stop method. The stop method should suspend the
applet's execution, so that it doesn't take up system resources
when the user isn't viewing the applet's page. For example, an applet that
displays an animation should stop trying to draw the animation
when the user isn't viewing it.
destroy Method
Many applets don't need to override the destroy method because
their stop method (which is called before destroy)
will perform all tasks necessary to shut down the applet's execution.
However, the destroy method is available
for applets that need to release additional resources.
destroy method as short as possible,
because there is no guarantee that this method will be completely executed.
The Java Virtual Machine might exit before a long destroy
method has completed.
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