1. Applets do not begin execution with a main() method but instead start when their class name is passed to an applet viewer or web browser. 2. There are two ways to run an applet: using an applet viewer or within a Java-compatible web browser by creating an HTML file with applet tags. 3. Using an applet viewer to run an applet is generally the fastest and easiest way to test an applet. The applet viewer executes the applet in its own window.

1. Applet Execution
1

2. Objectives
On completion of this period, you will be able to
learn
• Applet execution
2

3. Recap
In the last class ,we have studied about
• How to write a simple applet program
• We have learned the importance of each
statement in the applet program
• Let’s learn how to execute an applet
3

4. Applet Execution
• Applets do not begin execution at
• main( )
• Instead, an applet begins execution when the
name of its class is passed to an applet viewer
or to a web browser
4

5. Applet Execution contd..
• The steps in execution of an applet program
• Type and save the applet program with a text
editor
• Compile in the same way that you have been
compiling other Java programs
• However, running SimpleApplet involves a
different process
5

6. Applet Execution contd..
• Two ways to run an applet:
1. Executing the applet within a Java-
compatible web browser
2. Using appletviewer
• An applet viewer executes your applet in a
window
• This is generally the fastest and easiest way
to test your applet
6

7. Applet Execution contd..
• To execute an applet in a Web browser, you
need to write a short HTML file
• That contains the APPLET tag
• Here is the HTML file that executes
• SimpleApplet:
• <applet code="SimpleApplet" width=200
height=60>
• </applet>
7

8. Applet Execution contd..
• The width and height arguments specify the
dimensions of the display area used by the
applet
• After you create this file, you can execute your
applet through web browser
• By loading this file, in the browser the
SimpleApplet program will be to be executed
8

9. Applet Execution contd..
• To execute SimpleApplet with an applet viewer,
you may also execute the HTML file shown
earlier
• For example, if the preceding HTML file is called
RunApp.html
• Then the following command line will run
SimpleApplet
• C:>appletviewer RunApp.html
9

10. Applet Execution contd..
• There is another approach to execute applet
using appletviewer
• The steps are
• Write the applet tag in the applet program itself inside
comments
• Write and save the applet program
• Compile as usual
• Execute applet using the following command
• appletviewer SimpleApplet.java
10

11. Applet Execution contd..
SimpleApplet source file looks like this:
import java.awt.*;
import java.applet.*;
/*
<applet code="SimpleApplet" width=200 height=60>
</applet>
*/
public class SimpleApplet extends Applet {
public void paint(Graphics g) {
g.drawString("A Simple Applet", 20, 20);
}
}
11

12. Summary
In this class, you have learnt
• Applets do not need a main( ) method
• Applets must be run under an applet viewer or a
Java-compatible browser
• User I/O is not accomplished with Java’s stream
I/O classes
• Instead, applets use the interface provided by
the AWT to interact with user
12

13. Frequently Asked Questions
• Write the different steps involved in Applet
execution
13

14. Quiz
1. Appletviewer tool is provided by JDK only test
the applet during the development of applet
1. true
2. false
14

15. Quiz
2. Is executing an applet using an appletviewer
is fastest and easiest way to test your applet
– yes
– no
15