APPLET PROGRAMMING

APPLET PROGRAMMING:-

Applet:-

 Ø Applet is the program that comes from the server, downloaded on the client computer and executed on the client computer.

 Ø Applet is a web based program.

 Ø Applet does not have main method.

 Ø In Applet we have to write applet tag as shown below

 Ø Here code, width and height are known as attributes.

 Ø Here the attribute will give some extra to the tag.

 Ø To execute Applet there are two ways. 

          They are:

1.     In Command prompt using appletviewer command

2.     Using web browser

 Ø In java.applet package there is only class known as Applet.

 Ø In java.awt package there are some set of classes to create GUI components.

Life Cycle of Applet:-

 Ø Life cycle consists of different stages like:

1.     init

2.     start

3.     stop

4.     destroy

NOTE:-

 Ø Before destroy () method, stop () method is executed.

PROGRAM:-

import java.applet.*;

import java.awt.*;

public class Appletdemo extends Applet

{

  public void paint(Graphics g)

  {

     g.drawString("Applet Programming",100,150);

  }

}

/*

*/

File Name: -    Appletdemo.java    

Commands:-

                       javac    Appletdemo.java

  appletviewer Appletdemo.java    

OUTPUT:-    

Applet is displayed with Applet Programming output.

NOTE:-

 Ø To see the output for the applet in the browser we have to write applet tag in separate file without comments and save that file with .html extension.

PROGRAM:-

File Name: -    Appletdemo.html    

OUTPUT:-    

Double click the html thenApplet is displayed with Applet Programming output.

PROGRAM:- To display some message in status bar

import java.applet.*;

import java.awt.*;

public class Appletdemo1 extends Applet

{

  public void paint(Graphics g)

  {

     showStatus("Information in status bar");

  }

}

/*

*/

File Name: -    Appletdemo1.java    

Commands:-

                       javac    Appletdemo1.java

  appletviewer Appletdemo1.java    

OUTPUT:-    

Applet is displayed with Information in status bar output in status bar

Passing Parameters to Applet:-

 Ø To pass parameters to applet we have to use param tag as shown below

PROGRAM:- To pass parameters to applet.

import java.applet.*;

import java.awt.*;

public class Appletdemo2 extends Applet

{

   public void paint(Graphics g)

   {

     String str=getParameter("STR");

     int x=Integer.parseInt(getParameter("X"));

     int y=Integer.parseInt(getParameter("Y"));

     g.drawString(str,x,y);

   }

}

/*

*/

File Name: -    Appletdemo2.java    

Commands:-

                       javac    Appletdemo2.java

  appletviewer Appletdemo2.java    

OUTPUT:-    

                      Applet is displayed with hello applets output

PROGRAM:- To show the life cycle of applet

import java.applet.*;

public class Appletdemo3 extends Applet

{

   public void init()

   {

     System.out.println("In init method");

   }

   public void start()

   {

      System.out.println("In start method");

   }

   public void stop()

   {

      System.out.println("In stop method");

   }

   public void destroy()

  {

     System.out.println("In destroy method");

  }

}

/*

*/

File Name: -    Appletdemo3.java    

Commands:-

                        javac    Appletdemo3.java

   appletviewer Appletdemo3.java    

OUTPUT:-    

                       In init method

                       In start method

                       In stop method

                       In destroy method

RESULT:-

                     The output is displayed in command prompt.