Applet execution

This ppt describes how the applet executes:-

1. 1
Applet Execution

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

3. 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

4. 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

5. 5
Applet Execution
•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
contd..

6. 6
Applet Execution
•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
contd..

7. 7
Applet Execution
•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>
contd..

8. 8
Applet Execution
•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
contd..

9. 9
Applet Execution
•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
contd..

10. 10
Applet Execution
•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
contd..

11. 11
Applet Execution
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);
}
}
contd..

12. 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

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

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

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