Uncategories Java Applet

Java Applet

OM MAURYA SIR 05:55
OM MAURYA SIR

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.

Lifecycle of Java Applet

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

Lifecycle methods for Applet:

The java.applet.Applet class 4 life cycle methods and java.awt.Component class provides 1 life cycle methods for an applet.

java.applet.Applet class

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.
Example given below:

import java.awt.*;
import java.applet.*;
public class MyApplet extends Applet 
{
public void init()
{
System.out.println("Applet initialized");
}
public void start()
{
System.out.println("Applet execution started");
}
public void stop()
{
System.out.println("Applet execution stopped");
}
public void paint(Graphics g)
{
System.out.println("Painting...");
}
public void destroy()
{
System.out.println("Applet destroyed");
}
}

java.awt.Component class

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.

How to run an Applet?

There are two ways to run an applet
  1. By html file.
  2. By appletViewer tool (for testing purpose).

Simple example of Applet by html file:

To execute the applet by html file, create an applet and compile it. After that create an html file and place the applet code in html file. Now click the html file.
  1. //First.java  
  2. import java.applet.Applet;  
  3. import java.awt.Graphics;  
  4. public class First extends Applet{  
  5.   
  6. public void paint(Graphics g){  
  7. g.drawString("welcome",150,150);  
  8. }  
  9.   
  10. }  

Note: class must be public because its object is created by Java Plugin software that resides on the browser.

myapplet.html

  1. <html>  
  2. <body>  
  3. <applet code="First.class" width="300" height="300">  
  4. </applet>  
  5. </body>  
  6. </html>  

Simple example of Applet by appletviewer tool:

To execute the applet by appletviewer tool, create an applet that contains applet tag in comment and compile it. After that run it by: appletviewer First.java. Now Html file is not required but it is for testing purpose only.
  1. //First.java  
  2. import java.applet.Applet;  
  3. import java.awt.Graphics;  
  4. public class First extends Applet{  
  5.   
  6. public void paint(Graphics g){  
  7. g.drawString("welcome to applet",150,150);  
  8. }  
  9.   
  10. }  
  11. /* 
  12. <applet code="First.class" width="300" height="300"> 
  13. </applet> 
  14. */  
To execute the applet by appletviewer tool, write in command prompt:
c:\>javac First.java
c:\>appletviewer First.java













Read more about Applet from http://javadevelopmenttricks.blogspot.in/2018/02/displaying-graphics-in-applet.html










































Next

« Prev Post










Previous

Next Post »











































        

      









Subscribe to:
Post Comments (Atom)