1. 1 Applets are small applications that are accessed on an Internet server, transported over the internet, automatically installed and run as a part of web document. Applets interact with the user through the AWT, not through the console based I/O classes. Applets

2. 2 Every applet that you create must be a subclass of Applet, in the java.applet package. Applets don’t have a main(). An applet begins execution when the name of its class is passed to an applet viewer or the web browser. Applets

3. 3 To execute an Applet Edit Java source file. Compile your program. Make an HTML file that contains the tag that loads the applet. Execute the applet viewer, specifying the name of your applet’s source file.

4. 4 Applet Architecture All applets are subclasses of Applet. An applet is a window-based program. Applets are event driven. The user initiates interaction with the applet.

5. 5 Applet class Applets override a set of methods that provide the basic mechanism by which the browser interfaces to the applet and controls its execution. init(), start(), stop() and destroy() – apply to applets and are defined by Applet. Applets override the paint() of the AWT Component class. This is called when the applet’s output is redisplayed.

6. 6 Life Cycle of an Applet When an applet begins:- – init() – first method – initializes variables – called only once. – start() – called after init()- used to restart an applet – called when an applet’s HTML document is displayed onscreen. – paint() – called when applet’s output must be redrawn. paint() has one parameter of type Graphics – this will contain the graphics context, which describes the graphics envt in which the applet is executing.

7. 7 Life Cycle of an Applet When an applet terminates:- – stop() – called when a web browser leaves the HTML document containing the applet – when it goes to another page. – destroy() – called when the envt determines that your applet needs to be removed completely from the memory.

8. 8 Life Cycle of an Applet

9. 9 Applet tag Applet tag is used to start an applet from an HTML document and from an applet viewer. Code – gives the name of the file containing applet’s compiled.class file. Width & Height size of the applet in pixels.