Exercise 16-1. Modify FirstApplet
to take advantage of the features of the Graphics
class, so that it displays the "Hello
World" message in a more visually interesting way.
Exercise 16-2. Modify the Clock applet so that it is configurable
via applet parameters, like the Countdown applet
is. Your modified applet should read parameters that specify the
update frequency for the time display, as well as the font, color,
and format of the time display. (See
java.text.SimpleDateFormat for a way to format
dates and times according to a specified pattern.) Also, add a
getParameterInfo( ) method that describes the
applet parameters you define, and modify getAppletInfo(
) to include a message describing your contribution to the
applet.
Exercise 16-3. Modify the Countdown applet so that it responds to
mouse clicks: if the mouse is clicked over the timer, it should reset
the time to its initial value.
Exercise 16-4. One of the key features of applets is that they are treated as
untrusted code and run under a SecurityManager
that prevents them from taking malicious actions such as reading
sensitive data, deleting files, or using the client machine to send
spam out across the network. Take a look again at Example 7-3 in Chapter 7, and write an
applet version of that class that attempts to perform restricted
actions. Use a TextField or
JTextField component to display the
applet's output.
