DISTINQUISH BETWEEN THE JAVA CONTRUCTS: APPLICATION AND APPLETS. WRITE AN APPLICATON AND APPLETS PROGRAMS.

DISTINQUISH BETWEEN THE  JAVA CONTRUCTS: APPLICATION AND APPLETS. WRITE AN APPLICATON AND APPLETS PROGRAMS.

 

CHAPTER ONE

Introduction

            An applets is a program written in the java programming language that can be include in an HTML page, much in the same way an image is include in a page.

When you use a java technology- enabled browser to view a page that contains an applet, the applet’s code is transferred to your system an execute by the browser’s java virtual Machine (JVM).for information and examples on how to include an applet in an HTML page, refers to this description of  tag.

            An Application at the other hand is more generic in scope and can include a desktop such as Microsoft Word or a cloud based application such as Gmail.

Applets by in large are never mentioned unless relating to the java implementation and concept. I addition applets are no longer as popular as they once were due to other emerging web based technologies.

            Using the term Applet to refer to a small specific application that performs one specific task may be accurate according to Wikipedia but would unfortunately fail in the effective communication department.

DISTINQUISH BETWEEN THE JAVA CONTRUCTS: APPLICATION AND APPLETS. WRITE AN APPLICATON AND APPLETS PROGRAMS.

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            Applets are “small applications”. They very differ in “real applications” in the fact that they normally are embedded in a narrow environment in which and only in which they can function, implementing a very limited functionality.

The term applet is more often used for browsers, where the <applet> tag is used in HTML to call java embedded application. Bandwidth constraints forced such applications is to be rather small, while security considerations forced them to be use only software already installed on the computer, which for java is its runtime (JRE).

            However, this term is also used (or misused?) with an expanded scope, and may then pertain to JavaScript, ActiveX, Flash or even HTML chunks (using the <DIV> tag), but is not limited to these environments. It then refers to a small and severely limited application with a small display (or none at all) which requires very little local installation (none is preferred).

Exactly the same tools are used to compile applets as are used to compile applications, so the only real difference in the end is the applet’s small physical size, limited functionality and no need for local installation.

CHAPTER TWO

THE DIFFERNCE BETWEEN APPLICATON AND APPLET

            The difference between application and a java applet is how they are executed. An Application is executed by a java interpreter that loads the application’s main class file, whereas an Applet is executed through a java interpreter that works with a browser and must be included on a Web page to run. Because java applets are executed on the web user’s computer, certain restrictions limit what they can do. If these restrictions were not in place, it would be easy  to write java program capable of planting viruses or violating the security of the Web user’s computer(for example, by  looking for Intuit’s Quicken programs and then sending all of your credit card numbers to internet site.

In generally, most Web browsers place the following restrictions on applets:

They cannot read or  write files to a user’s file system

They cannot make networks connections other to the host where they originated.

They cannot start a program on the computer on which they are running.

They cannot load program or library files that are stored on the computer on which they are running.

A java application must have a main() method, which is where the application starts to execute. An applet uses other methods, such as init(), start(), stop(), and destroy(). However, it is possible to write a class that can be used as both an application and an applet, because applets ignore the main() method when they are executed.

CHAPTER THREE

AN APPLICATIONS PROGRAM

Below is an example of a very simple program

Import javax.swing.*;

Public class HelloWordSwing{

Public static void main(String[] args){

Final JLabel label = new JLabel(“HelloWordSwing”);

Frame.getContentPane().add(label);

Frame.setDefaultCloseOperation(JFrame.EXIST_ON_CLOSE);

Frame.pack();

Frame.setVisible(true);

}

}

CHAPTER FOUR

AN APPLES PROGRAM

import java.applet.*;

import java.awt.*;

public class main extends Applet{

public void paint(Graphics g){

g.drawString(“Welcome in java Applet.”40,20);

}

}

CHAPTER FIVE

CONCLUSION

            Application is a java class that has a main()method. An applet is a java class which extends java.applet.Applet. Generally, application is a standalone program, normally launched from the command line, and which has unrestricted access to the host system. An applet is a program which is run in the context of an applet viewer or web browser, and which has strictly limited access to the host system.

For instance, an applet can normally not read or write files on the host system whereas an application normally can. The actions of both applets and applications can be controlled by Security Manager Objects.

            Applets may communicate with other applets running on the same virtual machine. If the applets are of the same class, they can communicate via shared static variables. If the applets are of different classes, then each will need a reference to the same class with static variables.