APPLET LIFE CYCLE

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Java Applet

Applet is a special type of program that is embedded in the webpage to generate the dynamic content. It runs inside the browser and works at client side.

Advantage of Applet

There are many advantages of applet. They are as follows:
  • It works at client side so less response time.
  • Secured
  • It can be executed by browsers running under many plateforms, including Linux, Windows, Mac Os etc.

Drawback of Applet

  • Plugin is required at client browser to execute applet.

Lifecycle of Java Applet

  1. Applet is initialized.
  2. Applet is started.
  3. Applet is painted.
  4. Applet is stopped.
  5. Applet is destroyed.




Applet Lifecycle


Life Cycle of an Applet

Four methods in the Applet class gives you the framework on which you build any serious applet −
  • init − This method is intended for whatever initialization is needed for your applet. It is called after the param tags inside the applet tag have been processed.
  • start − This method is automatically called after the browser calls the init method. It is also called whenever the user returns to the page containing the applet after having gone off to other pages.
  • stop − This method is automatically called when the user moves off the page on which the applet sits. It can, therefore, be called repeatedly in the same applet.
  • destroy − This method is only called when the browser shuts down normally. Because applets are meant to live on an HTML page, you should not normally leave resources behind after a user leaves the page that contains the applet.
  • paint − Invoked immediately after the start() method, and also any time the applet needs to repaint itself in the browser. The paint() method is actually inherited from the java.awt.

For creating any applet java.applet.Applet class must be inherited. It provides 4 life cycle methods of applet.
  1. public void init(): is used to initialized the Applet. It is invoked only once.
  2. public void start(): is invoked after the init() method or browser is maximized. It is used to start the Applet.
  3. public void stop(): is used to stop the Applet. It is invoked when Applet is stop or browser is minimized.
  4. public void destroy(): is used to destroy the Applet. It is invoked only once.
The Component class provides 1 life cycle method of applet.
  1. public void paint(Graphics g): is used to paint the Applet. It provides Graphics class object that can be used for drawing oval, rectangle, arc etc.







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