This document discusses the life cycle of an applet, which includes born, running, idle, and dead states. In the born state, the init() method is called to initialize the applet. In the running state, the start() method runs the applet and paint() displays it. The applet becomes idle when leaving the page. The stop() method terminates any running threads and destroy() cleans up resources in the dead state. Applets are useful for dynamic web page elements, interactive presentations, and remotely storing applets for others to use.

1. A Presentation On Object Oriented Programming
Topic : LIFE CYCLE OF
APPLET
Presented By:
Richa Dasila.
160030101045
AMRAPALI INSTITUE OF TECHNOLOGY AND SCIENCES

2. CONTENTS:
Introduction.
Life Cycle.
Application.

3. Introduction:
 Java programs used in internet computing to respond the user.
 Applet=Java Byte Code + HTML page.
 They can be transported over the internet and can run using
AppletViewer / Web browser supporting java.
 Embedding Applets into web pages can be done via Local Applets or
Remote Applets .

4.  The Applet class is itself a subclass , the inheritance
may be better represented as:
java.lang.Object java.awt.Component java.awt.Container
java.awt.Paneljava.applet.Applet

5.  The Applet class uses the services of two classes namely, Applet and Graphics .
 Applet package provides life and behaviour to the applet through methods such
as init(), start() etc.
 Unlike other applications which call the main() method to execute the code .
When an applet is loaded java automatically calls a series of Applet class
method for starting,running and stopping thereby following a lifecycle.

6. Life Cycle:
Running
State
Idle
State
Dead
State.
Born
State
END.

7. BORN
STATE
init() :
This method is
used for
initialization
 Following Things can be done:
i. Objects can be created using Applet.
ii. Initial Values can be set.
iii. Colors can be set.
iv. Load fonts .
 This can be done only once in an applet’s life cycle.
BORN STATE.

8.  To provide any behaviour we must override the init() function.
 Syntax:
public void init()
{
………………..
…………..(Action)
…………………
}

9. RUNNING
STATE
start()
THE RUNING
STATE
 Applet enter this stage when :
 System calls the start() method of Applet class , this method is automatically called after
the init () .
 Applet is resumed from the idle stage after some activity by the user in different page.
• This method unlike init() can be called more than once , we may override the start()
method to create a thread to control applet.

10.  The syntax:
public void start()
{…………
……….(Action)
…………
}

11.  Applet moves to paint method to perform output operations on screen .
 This happens immediately after entering the running stage.
 The display stage is not considered as a part of applet’s life cycle .
 The default version of the display state does absolutely nothing.
 Syntax:
public void paint(Graphics g)
{……………
………(Action)
}
DISPLAY
STAGE
paint()
THE DISPLAY STAGE

12. IDLE
STATE stop()
THE IDLE STAGE:
 An Applet becomes idle when we leave the page containing the currently running
applet.
 If we use a thread to run the applet , we must use stop() method to terminate the
thread.
 We must override the stop() method.
 Syntax:
public void stop()
{………..
…..(Action)
……..
}

13. DEAD
STATE
destroy()
THE DEAD
STAGE
 Dead State = Removed from memory.
 This occurs automatically when we exit the browser
state.
 Invoking the destroy() method cleans up the
resources created by the applet.
 It can be overridden only once like the init() stage.

14.  Syntax:
public void destroy()
{
……………..
……(Action)
………….
}

15. APPLICATION:
 When we need something dynamic in the webpage :
Smart Presentation of statistical data.
 When we require flash outputs : Creative
presentation.
 Creating Remote Applets and storing them in the
internet for others to download and use.