1

A PROJECT REPORT

ON

UNIVERSAL BROWSER

Project work submitted in partial fulfillment of the requirement forthe award of degree of

BACHELOR OF TECHNOLOGYIN

COMPUTER SCIENCE & ENGINEERING

BY S.RAVI KIRAN M.RAKESH G.RAVI PRAKASH REDDY G.PRITHVI RAJ

CH.PRAVEEN KUMAR

UNDER THE ESTEEMED GUIDANCE OF

Mr.K.C.KRISHNAIAH Associate Professor

Dept. of Computer Science & Engineering

Department of computer Science & Engineering

NARAYANA ENGINEERING COLLEGE (Affiliated to J.N.T.U., Hyderabad)

NELLORE 2004

DEPARTMENT OF COMPUTER SCIENCE & ENGINEERING

NARAYANA ENGINEERING COLLEGE

(AFFILIATED TO JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY,HYDERABAD)NELLORE

CERTIFICATE

This is to certify that Project Report entitled “UNIVERSAL BROWSER”

is the bonafide work done by S.RAVI KIRAN, CH.PRAVEEN KUMAR,

G.PRITHVI RAJ , G.RAVI PRAKASG REDDY, M.RAKESH in the partial

fulfillment of requirements for the Award of the Degree of BACHELOR OF

TECHNOLOGY IN COMPUTER SCIENCE & ENGINEERING.

(Mr.K.C.KRISHNAIAH) Mr.K.C KRISHNAIAH) PROJECT GUIDE HEAD OF THE DEPARTMENTDEPT.OF COMPUTER SCIENCE & DEPT.OF COMPUTER SCIENCE &

ENGINEERING ENGINEERING

EXTERNAL EXAMINERS:

ACKNOWLEDGEMENT

The satisfaction and excitement that Accompanies the successful

completion of any task would be incomplete without mentioning the people who

made it possible, because success is the essence of hard work, perseverance,

undeterred missionary Zeal, persistent determination and most all

“ENCOURANGING GUIDANCE”.

We express our gratitude to our institution chairman Dr.P.Narayana

garu, “NARAYANA ENGINEERING COLLEGE” Nellore. We are deeply

indebted to Dr.P.Gopal Reddy garu, Principal for his benevolent good

suggestion that motivated us to do our project and also for his continuous

support in accomplishing the requirement that fulfill the completion of project.

We are extremely grateful to our beloved Head of the Department,

Computer science & Engineering Mr. K.C.Krishnaiah garu for providing us

means of attaining our most cherished goals.

Our heartfelt thanks and gratitude to our guide Asst.professor

Mr.K.C.Krishnaiah garu for providing us an opportunity to carry out this project,

along with the purposeful guidance and moral support extended to us throughout

the duration of the project work.

Eventually we are grateful to our lab technicians and number of

individuals whose professional guidance, assistance and encouragement have

made it a pleasant endeavor to undertake this project.

ABSTRACT

The Browser we normally use such as “internet Explorer” and “Netscape” is generally limited by the capability with the number of servers it can communicate. It cannot be possible to communicate with FTP server using “Internet Explorer” and “Netscape”. Also it also lacks the ability to store “Text Files” in server address space. To overcome the above difficulties we are intended to develop a project which can efficiently handled the above requirements, using JAVA technology. Our project basically consists of 3 modules.

1) E-cabinet Module: This module provides the facility to store text files in the server

address space in the intended user’s login. This module is implemented using

JAVA

“Socket “ and “Server Socket” classes.

2) HTTP Module:

This module provides the basic navigator function to navigate over

the “web pages”. Also it consists of several sub-modules, which provides all the

basic functionalities that we normally encountered in “Internet Explorer”.

3) FTP Module: This Module makes it possible to communicate with the FTP server. Once we connect to the FTP server we can perform the basic “UpLoading” and “DownLoading” operations with FTP server.

1.INTRODUCTION

1.1 HISTORY OF THE PROJECT:

In the present world, communication has become more of a

necessity for the people all over the world. The evolution of the Internet made it

possible for people all over the world communicate with one another irrespective

of their location. The revolution of World Wide Web made it possible for people

all over to access to the information available on World Wide Web with just a

mouse click. There are several browsers that make the user access to web

pages present in several web servers across the Internet. There are some

browsers that are able to communicate with ftp servers and allow 2-way file

transfer. The thought of combining the functionalities of both these browsers into

a single browser lead us to create this universal browser.

1.2 EXISTING SYSTEM:

The Browser we normally use such as “internet explorer “ or

“Netscape” is generally limited by the capability with the number of servers in it

can communicate to. For example it could be not able to communicate with FTP

server when considering Internet Explorer or Netscape. Also when considering

these clients with FTP scheme they normally lack the ability to support for

uploading files to the server. Another most important feature is to store and

retrieve information in the most efficient, easy, and timesaving manner. There are

many software which have been developed across cyberspace and networks in

order to store data in files as well as retrieve these files as and when needed or

desired. There are situations where a person may be connected to the Internet or

the World Wide Web through his personal computer. It is not unreasonable to

expect such a person to also travel a lot, in which case, he does not enjoy the

luxury of having ready gigabytes at his disposal. Of course, the onset of laptops

and palmtops surely do provide this facility but not all people can afford them.

Hence, our discussion converges to this point also: “that people

need a hard disc or at least a miniature hard disc in cyberspace where they can

store their important text files and can access these files from any place in the

world”, provided they are connected to the Internet.

1.3 OUR PROJECT:

This project is an effort to update the existing system by

developing a browser that communicates with all WEB SERVERS on the

WORLD WIDE WEB (to process HTTP requests) and can also communicate

with FTP SERVER for mutual file transfer. Along with these an additional

functionality called E-CABINET is incorporated so that users can store and

retrieve their personal files under their login by registering some server

space on a network. To achieve the above-mentioned requirements we

need a platform independent client and hence we extensively used JAVA, a

platform independent language for the project. Our aim is to develop a

multipurpose platform independent client with the ability to support HTTP,

FTP servers and has the additional feature of E-CABINET.

2. SUBJECT REVIEW

2.1 About JAVA Swing:

Generally a Graphical User Interface presents a pictorial interface to

a program. A GUI gives a program a distinctive look and feel by providing different

applications with a consistent set of intuitive user interface components. GUIs allow

the user to spend less time trying to remember which keystroke sequences do what

and spend more time using the program in a productive manner. GUIs are built from

GUI components. A GUI component is an object with which the user interacts via the

mouse or the keyboard .The classes that are used to create the GUI components are

part of the SWING GUI components from package javax.swing.

The original GUI components from the Abstract Windowing Toolkit

package java.awt are tied directly to the local platform’s graphical user interface

capabilities. So a JAVA program executing a different JAVA platform has a different

appearance and sometimes even different user interactions on each platform. These

are the newest GUI components of the JAVA 2 platform. Swing components are

written, manipulated and displayed completely in JAVA and are so-called pure java

components. Swing components are often referred to as “light-weight components”.

They are written completely in JAVA so they are not “weighed down” by the complex

GUI capabilities of the platform on which they are used. AWT components that are

tied to the local platform’s windowing system to determine their functionality and their

look and feel .The GUI we designed to implement our Browser using the swing

components is as shown

MENU Bar Buttons Tool Bar

Layout Managers:

Layout managers are provided to arrange GUI components on a

container for presentation purpose. The layout managers provide basic layout

Editor Pane

capabilities that are easier to use than determining the exact position and size of every

GUI component. This enables the programmer to concentrate on the basic “look and

feel” and lets the layout managers process most of the layout details.

Flow Layout:

Flow Layout is the most basic layout manager. GUI components are

placed on a container from left to right in the order in which they are added to the

container. When the edge of the container is reached, components are continued on

the next line. Class Flow Layout allows GUI components to be left aligned, centered

and right aligned

Border Layout:

The BorderLayout layout manager arranges the components into five

regions: north, south, center, east, west. A max of 5 components can be added

directly to the BorderLayout – one for each region. The components placed in the

North and South regions extend horizontally to the sides of the container and are as

tall as the components placed in those regions. The East and West regions expand

vertically between the North and South regions and are as wide as the components

placed in those regions. The component placed in the Center region expands to take

all remaining space in the layout.

GridLayout

The GridLayout layout manager divides the container into a grid so that

components can be placed in rows and columns. Class GridLayout inherits directly

from OBJECT and implements interface LayoutManager. Every Component in a

GridLayout has the same width and height. Components are added to a GridLayout

starting at the top-left cell of the grid and proceeding left-to-right until the row is full.

Then the process continues left-to-right on the next row of the grid.

Panels:

Complex GUI requires that each component be placed in an exact

location. They often consist of multiple panels with each panel’s components arranged

in a specific layout. Panels are created with class Jpanel. Jpanel’s may have

components including other panels added to them.

Using Menus with Frames :

Menus are an integral part of GUIs. Menus allow the user to perform

actions without unnecessarily “cluttering” a graphical user interface with extra GUI

components. In swing GUIs menus can only be attached to objects of the classes that

provide method setJMenuBar. Two such classes are JFrame and JApplet. The

classes used to define menus are JMenuBar, JMenuItem, and JMenu.

“Class JMenuBar contains the methods necessary to manage a

menubar. A menubar, which is a container for menus”.

“Class JMenuItem contains the methods necessary to manage menu

items. A menu item is a GUI component inside a menu that when selected causes an

action to be performed. A menu item can be used to initiate an action or it can be a

submenu that provides more menu items from which the user can select.”

“Class JMenu contains the methods necessary to manage menus.

Menus contain menu items and are added to menu bars or to other menus as

submenus. When a menu is clicked, the menu expands to show its list of menu items.

Clicking a menu item generates an action event”.

Menu Item Menu

.

Using JPopupMenus:

Many of today’s computer applications provide so-called context-sensitive

popup menus. In Swing, such menus are created with class JpopupMenu.These

menus provide options that are specific to the component for which the popup trigger

event was generated. The popup trigger event occurs when the user presses and

releases the right mouse button.

Popup Menu

Using JDesktopPane and JInternalFrame:

For any application the only way a user can view the visibility of the application through its GraphicalUserInterface.Many applications use a multiple document interface containing other windows to manage several open documents that are being processed in parallel. For example the mail option in Internet Explorer can be viewed as a multiple document interface. JAVA Swing technology provides this MDI format through its two most important classes.

JDesktopPane JInternalFrameThese two classes provide the support for creating multiple document interfaces.

Constructor for creating the desktop object is as follows Final JDesktopPane JD = new JDesktopPane ()This desktop object will act as a Parent Window. Any child windows that are created will be added to this desktop object. For any application there can be any number of child windows but there must be exactly one parent window.

Child windows can be created using the class “JInternalFrame”.The constructor for creating Internal frames is JInternalFrame frame = new JInternalFrame (“Child Frame”, true, true, true, true)

The constructor consists of five arguments. First argument in the constructor indicates the name of this internal frame.

Second argument is a Boolean indicating if the internal frame should be resizable by the user.

Third argument is a Boolean indicating if the internal frame should be closable by the user.

Fourth is also a Boolean indicating if the internal frame should be maximizable by the user.

Fifth is last Boolean argument indicating if the internal frame should be minimizable by the user.

A JInternalFrame has a content pane to which components can be attached. The method used for obtaining the content pane is

“getContentPane ()”.

USING BOX Layout:

The BoxLayout layout manager arranges the GUI components horizontally along the X-axis or vertically along the Y-axis of a container.

Box bxAddrBar = new Box (BoxLayout.X_AXIS); Box bxNorth = new Box (BoxLayout.Y_AXIS); Box bxCenter = new Box (BoxLayout.X_AXIS); Box bxSouth = new Box (BoxLayout.X_AXIS);

Here “bxAddrBar”,”bxNorth “, “bxCenter”,”bxSouth” are the “BOX” containers that uses BoxLayout as its default layout manager.

The first container uses “BoxLayout.X_AXIS” as its layout manager. This means that the components are arranged in horizontal fashion from left to right

Similarly the second container uses “BoxLayout.Y_AXIS” as its layout manager. This means that the components are arranged from top to bottom in vertical fashion.

Similarly the third and fourth containers uses “Horizontal” layout’s as its layout managers Basically this Container splits the InternalFrame into Boxes. Each Box can have it’s own layout manager. Each component will be added in sequential fashion either in horizontally or vertically.These BOX containers are used for arranging the components in regular fashion. Once the components are added to these containers this containers can be added to Internal Frames. USING JTree:

With the JTree class, you can display hierarchical data. A JTree

object doesn't actually contain your data; it simply provides a view of the data.

Like any non-trivial Swing component, the tree gets data by querying its data

model. Here's a picture of a tree:

As the preceding figure shows, JTree displays its data vertically.

Each row displayed by the tree contains exactly one item of data, which is called

a node. Every tree has a root node from which all nodes descend. By default, the

tree displays the root node, but you can decree otherwise. A node can either

have children or not. We refer to nodes that can have children — whether or not

they currently have children — as branch nodes. Nodes that can't have children

are leaf nodes.

Branch nodes can have any number of children. Typically, the

user can expand and collapse branch nodes — making their children visible or

invisible — by clicking them. By default, all branch nodes except the root node

start out collapsed.

This JTree has been used in our project to display the list

of URL’s that have visited in the form of an Hierarchical way.

2.2 About JAVA NET Package:

SOCKET OVERVIEW :

A network socket is a lot like an electrical socket. Various plugs around

the network have a standard way of delivering their payload. Anything that

understands the standard protocol can “plug in “ to the socket and communicate. A

server is anything that has some resource that can be shared.

A client is simply any other entity that wants to gain access to a particular server. The

server is a permanently available resource where as a client is free to “unplug “ after it

has been served. A port is a numbered socket on a particular machine. A server

process is said to “LISTEN” to a port until a client connects to it. For FTP default port

number is 21 where as for HTTP it is 80.The-networking classes mainly used in this

software design are InetAddress, URL, Socket, ServerSocket, SocketImpl.

InetAddress:

The InetAddress class is used to encapsulate both the numerical IP

address and the domain name for that address. We interact with this class by using

the name of IP host, which is better than the numerical address. This class hides the

number inside.

URL:

The URL provides a reasonably intelligible form to uniquely identify or

address information on the Internet. The URL specification is based on four

components. First one is protocol to use, second one is host name or IP address, third

one is port number, which is optional, and last one is actual file path. This class has

several constructors and each can throw a MalformedURLException.

Those are

URL (String urlspecifier)

URL (String protocol Name, String hostname, int port, String path)

URL (String protocol Name, String hostname, String path)

SERVER SOCKET:

This class is used to create servers that listen for either local or remote

client programs to connect to them on published ports. This section develops the

operational web server. When we create a server socket it will register itself with the

system having an interest in client connections. The constructors for this class reflect

the port number that we wish to accept connections on and, optionally, how long we

want the queue for said port to be.

The constructors are

ServerSocket (int port) creates server socket on the specified port with a

queue length of 50.

ServerSocket (int port, int marquee) creates a server socket on the specified

port with a maximum queue length of 50.

ServerSocket (int port, int maxqueue, InetAddress local address) same as

above and on a multithreaded host local address specifies the IP address to

which this socket binds.

2.3 About IO Package:

CHARACTER STREAMS:

The byte stream classes provides functionality to handle any type of

I/O operation, they cannot work directly with Unicode characters. So it was

necessary to include direct I/O support for characters. The main classes used

here are Reader, Writer, File Reader, and File Writer.

READER:

Reader is an abstract class that defines java’s model of streaming

character input. All the methods in this class will throw an IOException on error

conditions. Read (char buffer [ ]) method is used in the reader class. This

method attempts to read up to buffer. Length characters into buffer and returns

the actual number of characters that were successfully read. -1 is returned when

end of file is encountered.

WRITER:

Writer is an abstract class that defines streaming character

output. All the methods in this class return a void value and throw an IOException

in case of errors. The methods used that belongs to this class are write (char

ch), write (char buffer [ ]). The first method writes a single character to the

invoking output stream. Second one writes a complete array of characters to the

invoking output stream.

FILE READER:

The FileReader class creates a Reader that we can use to read the

contents of a file.

The constructors are

FileReader (String filepath)

FileReader (File fileobj)

Either can throw a FileNotFoundException. Here file path is a full path

name of a file and fileobj is a File object that describes the file.

FILEWRITER:

FileWriter creates a Writer that we can use to write to a file.

The constructors are shown here.

FileWriter(String filepath)

FileWriter(String filepath,Boolean append)

FileWriter(File fileobj)

They can throw IOException. Here filepath is the full path name of a file.

Fileobj is a File object that describes the file. If append is true then output is

appended to the end of file.FileWriter will create the file before opening it for

output when you create the object. In case where you attempt to open a redonly

file an IOException will occur.

File:

The file class does not operate on streams it deals directly with

files and filesystem. It does not specify how it is retrieved from or store in files, it

describe the properties of the file itself. A file object is used to manipulate or

obtain int associated with a disk file and to navigate subdirectory hierarchies.

Files are a primary source id destination for data. There are central resources for

storing persistent and shared int.

The Constructors are shown here:

File (string directorypath)

File (string directorypath,string Filename)

File (dir obj, string Filename)

Methods in a file

Getname( ) returns the name of the file

GetParent( ) returns name of parent directory

Exists( ) returns true if file exists

File includes two verbal utility methods

Boolean RenameTo(file newname)

Here the filename specified by “newname” becomes the name

of the involving file object .it will be return true upon success.

Boolean delete( )

Which deletes the disk file. File is represented by the path of

the involving FILE object. It is also used to delete a directory when it is

empty.

2.4 ABOUT UITL PACKAGE :

1.VECTOR:

It implements a dynamic array. It is similar to array list but with two differences. The vector is synchronized, and it consists many legacy methods. Those are not part of the collection framework. In java2 vector was reengineered to extend abstract list and implement the list interface. Now it is computable with collections.

All vectors start with an initial capacity. After this initial

capacity is reached, the next time that you attempt to store an object in the

vector, the vector automatically allocates space for that object plus extra room

for add1 object. By allocation more than required no of vectors the no of

allocations made to be reduced. Vector defines these protected data members.

Int capabilityIncrement; stores the increment value.

Int element counts; counts no of elements.

Object elementdata [ ]; stores the array that holds the vector.

After you initiate a vector, you can add element to it by

calling addelement ( ).

To obtain the element at a specific location call elementAt ( ).

To obtain the first element in the vector call firstelement ( ).

To ret rive the last element call lastelement ( ).

You can obtain the index of an element by using indexof ( ) and

lastindexof ().

To remove an element, call removeelement ( ) or removeelementat ( ).

2.STRING TOKENIZER:

It provides the 1st step in the parsing process. Often called

lexical analysis or scanner. This class implements the enumeration interface.

Therefore, given a string, you can enumerate the individual tokens contained in it

using string tokenizer.

To use this we have to specify the input string that contains delimiters. Delimiters are characters that separate tokens. For example ( ; : ).sets delimiters to comma, semicolon, colon. The default set of delimiters consists of the white space characters space, tab, new line and carriage return.

In this the next token () method is used to extract

consecutive tokens.

Hasmoretokens ( ) method returns true while there are more tokens to be

extracted. It implements the next element and has more elements () method also.

It is used to show the tokens one by one.

Methods are

Stringtokenizer (string str)

Stringtokenizer (string str, string delimiter)

Stringtokenizer (string str, string delimiter, boolean delimiterstoken)

3. ANALYSIS

3.1 Problem specification

Vision: The problem is “to design a browser that has the functionalities of i) Communicating with web servers on the world wide webii) Communicating with ftp servers over the web for mutual file transferiii) Providing a virtual address space on the server for registered users”

3.2 Systems Specification

The hardware and software requirements for our software

are listed below:

Hardware specification

Processor Specification: Pentium III

RAM: 128 MB (min 64 MB)

Hard Disk: 40 GB (min 2 GB)

Monitor: 14 inches

Key Board: ZENITH

Mouse: ZENITH

Software specification :

Operating system: Windows 2000

Front end : JAVA

3.3 Feasibility Study

Feasibility study is necessary to determine whether the proposed

system is feasible considering technical, operational and economical factors. It is

both necessary and prudent to evaluate the feasibility of a project at the earliest

possible time. This study decides whether to continue with the project at the

initial stage.

OPERATIONAL FEASIBILITY:

The proposed system entails a minimum basic knowledge of the computer system on part of the user. The user friendly, easy to use interfaces encourages user to adapt to the system. The maintenance of the system requires minimum of efforts.

The present system is not an exe file supported by windows. The software works only in the presence of JDK1.3 STANDARD EDITION, which supports SWING, UTIL, IO, NET packages.

In view of the above, the software is operationally feasible.

TECHNICAL FEASIBILITY :

In the present system, the GUI is user friendly and does not

require must expertise and training. It just needs a mouse click to perform any

function.

The system is implemented using java 1.3 on

windows 2000 operating system. This project mostly uses swing components to

design the Graphical User Interface which is provided by Java Foundation classes. A

client to server connection is to be established. The required site is to be accessed

based on the URL address of the site. Java.Net package is mostly used.

ECONOMICAL FEASIBILITY:

The development of the system needs minimum amount of

cost on part of the developer .The project is developed entirely using JAVA

hence there is no constraints of mixing various languages. Also there is no need

of a backend for our project, which makes it economically viable. The

maintenance cost is also less. The proposed system doesn’t need additional

procurement of software or hardware for its development, as they are readily

available. Hence the project is economically feasible.

3.4 System Analysis

3.3.1 E-cabinet Module

Introduction :

This project is a software designed to run on a LAN

network, which can be extended to the Internet, using which a small amount of disc

space on the server machine is allocated to each client who signs up for the service.

To achieve this, the software has been coded in Java so that a wide range of software

tools is available for implementation. As the basic concept is that clients store their

data on disc space of the server, a basic networking model has to be followed. For this

purpose the Java packages java.net has been used.

The Socket class and the Server Socket class

provide the necessary framework to base this software. In addition, in order to give the

user maximum ease to operate the software, a graphical user interface has been

provided. For this reason, extensive use has been made of the packages Java.awt,

Java. net, Java.io, Javax.swing. In order to attain compatibility with the mouse, as

users tend to be biased towards the mouse, the package Java.awt.event has been

used to trap and respond to mouse events. The package Javax.swing is a feature of

the extended version in Java 2.0.

The package Java.io is used for file management

in the software. The package Java.util has been used extensively. The software

consists of two programs namely the Server and the Client. The Server is a java

application program while the Client is a java applet. Thus, the Client program uses

the java.Net package for its running.

As the software is meant to serve many clients

at the same time, and the service be provided by only a single server, the essential

criterion is that multithreading be used. Thus for each client request the server spawns

a thread to take care of the execution of that client. Multithreading is achieved using

the versatile Thread class in conjugation with the Runnable interface.

The software uses the Vector data structure to

have an exchange of information over the network between the Server and each

instance or thread of a client. In essence, the Java Virtual Machine uses the TCP/IP

protocol when it uses the Socket and the Server Socket class, so the software

implicitly uses the TCP/IP protocol for its implementation.

Overview Of The Software:

The software is implemented by dedicating a computer as

well as its hard disk to the server. The server program runs continuously and

waits for a connection to be established by a client with it. This means that the

server listens for incoming connections at a particular port. In the program, the

server listens for the connections at the port 1055. When a client is run using the

appletviewer of the Java Development Kit an applet is run at the client terminal.

The client first informs the server of its connection. In response the server

spawns a thread for all execution related to the client. If many clients establish

connections and thereafter execute concurrently, many threads are spawned in

parallel. These threads run independent of one another and so the concept of

multithreading is central to the software.

Once the client starts, it offers the user the choice to

sign up if he has not previously created a login. Once the user logs in, the

password is matched at the server side and if it matches the two buttons to Read

and Save files get activated. Now one can save one’s files by merely clicking on

Save and then choose one’s file through the file dialog box. If one wants to read

the files one has stored in her login, she needs to click on the Read button

whereupon the server sends the list of files currently in her login. In addition,

buttons are provided to either open, rename or delete the file as per the user’s

requirement.

When the window of the applet is closed, the applet gets

destroyed. But before getting destroyed, the program closes all the open sockets

of the thread which produced the applet. When the server frame is closed, the

server socket gets closed and hence no more listens for incoming connections.

At this stage if there is a request from a client the message is displayed that

there is no Network Connection.

3.3.2 FTP Module:

INTRODUCTION:

The ability to transfer files from one machine to another is

often accomplished using an FTP client. In order to achieve the desired

functionality we have extensively used the predefined classes provided by JAVA

- programming language. JAVA provided soo many builtin functions that provided

the basic functionalities of the FTP client

FTP stands for File Transfer Protocol. It is a universal protocol (set of rules and

commands) that is used between two computers to transfer files. Since the

Protocol is universal the file transfer can be done between PC, Mac, Unix or any

other prehistoric machine.

The objectives of FTP are

1. to promote sharing of files (computer programs and/or data)

2. to encourage indirect or implicit (via programs) use of remote computers

3. to shield a user from variations in file storage systems among hosts

4. to transfer data reliably and efficiently.

FTP, though usable directly by a user at a terminal, is

designed mainly for use by programs. The communication path between the

USER-PI and SERVER-PI is used for the exchange of commands and replies. A

full duplex connection over which data is transferred, in a specified mode and type.

The data transferred may be a part of a file, an entire file or a number of files. The

path may be between a server-DTP and a user-DTP, or between two server-

DTPs. The passive data transfer process "listens" on the data port for a connection

from the active transfer process in order to open the data connection.

ANALYSIS

FTP is a protocol that manages files on a remote machine.

It has commands for copying files to and from remote machine and for renaming

and deleting files. You have to first make a connection to the remote server.

Then you will be able to download or upload files. You will feel as if you are

directly working on the other machines. There is no need to worry about the

security. Don’t think FTP will also allow others to connect to the same remote

system and download your files. It protects access by user name and password

combinations as is done on most of today’s systems. But it also has a form called

“ANONYMOUS FTP”. Here username “ANONYMOUS” is recognized as valid

without any password.

Assume that you have some technical stuff in your system

and you wish to provide that to others. Then in normal FTP you should have

given username and password to all those who wish to take your services. It is

also boring for both of you if others are going to take the information only once.

Others should ask you for a login id and password and you have to assign them.

They will throw away their id after use but your server still maintains them in the

user list.

In such occasions you will find “ANONYMOUS FTP”

useful. They will just login as ANONYMOUS and the system will not ask for any

password they can take the free stuff from your server. Here the users will have

only limited access.

The secured exchange of files in FTP consists of the

following steps.

1. Opening a connection to the remote computer and identification of the user.

2. File exchange (Get or Put file).

3. Closing the connection.

FTP allows exchange of all types of files with 2 settings.

ASCII for simple text files and Binary for files like Word Processor documents,

Graphics, Video, Audio or executable files that contain special character codes.

FTP has a list of commands similar to DOS like dir, cd etc…

The data transfer process establishes and manages the

data connection. The DTP can be passive or active. Access controls define

users' access privileges to the use of a system, and to the files in that system.

Access controls are necessary to prevent unauthorized or accidental use of files.

It is the prerogative of a server-FTP process to invoke access controls.

Pathname is defined to be the character string, which must be input to a file

system by a user in order to identify a file. Pathname normally contains device

and/or directory names, and file name specification. FTP does not yet specify a

standard pathname convention.

Each user must follow the file naming conventions of the

file systems involved in the transfer. The data transfer process, in its normal

"active" state, establishes the data connection with the "listening" data port.It sets

up parameters for transfer and storage, and transfers data on command from its

PI. The DTP can be placed in a "passive" state to listen for, rather than initiate a

connection on the data port.

server-FTP process

A process or set of processes which perform the function

of file transfer in cooperation with a user-FTP process and, possibly, another

server. The functions consist of a protocol interpreter (PI) and a data transfer

process (DTP).

server-PI

The server protocol interpreter "listens" on Port L for a

connection from a user-PI and establishes a control communication connection.

It receives standard FTP commands from the user-PI, sends replies, and

governs the server-DTP.

type

The data representation type used for data transfer and

storage. Type implies certain transformations between the time of data storage

and data transfer. The representation types defined in FTP are described in the

Section on Establishing Data Connections.

DATA TRANSFER FUNCTIONS

Files are transferred only via the data connection. The

control connection is used for the transfer of commands, which describe the

functions to be performed, and the replies to these commands (see the Section

on FTP Replies). Several commands are concerned with the transfer of data

between hosts. These data transfer commands include the MODE command

which specify how the bits of the data are to be transmitted, and the STRUcture

and TYPE commands, which are used to define the way in which the data are to

be represented. The transmission and representation are basically independent

but the "Stream" transmission mode is dependent on the file structure attribute

and if "Compressed" transmission mode is used, the nature of the filler byte

depends on the representation type.

When the data reaches the receiving host, it will be

transformed in a manner dependent on the logical byte size and the particular

host. This transformation must be invertible (i.e., an identical file can be

retrieved if the same parameters are used) and should be well publicized by

the FTP implementors.

For example, a user sending 36-bit floating-point numbers

to a host with a 32-bit word could send that data as Local byte with a logical

byte size of 36. The receiving host would then be expected to store the logical

bytes so that they could be easily manipulated; in this example putting the 36-

bit logical bytes into 64-bit double words should suffice.

In another example, a pair of hosts with a 36-bit word size

may send data to one another in words by using TYPE L 36. The data would be

sent in the 8-bit transmission bytes packed so that 9 transmission bytes carried

two host words.

FORMAT CONTROL

The types ASCII and EBCDIC also take a second

(optional) parameter; this is to indicate what kind of vertical format control, if any,

is associated with a file. The following data representation types are defined in

FTP:

A character file may be transferred to a host for one of

three purposes: for printing, for storage and later retrieval, or for processing. If a

file is sent for printing, the receiving host must know how the vertical format

control is represented. In the second case, it must be possible to store a file at a

host and then retrieve it later in exactly the same form. Finally, it should be

possible to move a file from one host to another and process the file at the

second host without undue trouble. A single ASCII or EBCDIC format does not

satisfy all these ditions. Therefore, these types have a second parameter

specifying one of the following three formats:

ESTABLISHING DATA CONNECTIONS

The mechanics of transferring data consists of setting up

the data connection to the appropriate ports and choosing the parameters for

transfer. Both the user and the server-DTPs have a default data port. The user-

process default data port is the same as the control connection port (i.e., U).

The server-process default data port is the port adjacent to the control

connection port (i.e., L-1).

The transfer byte size is 8-bit bytes. This byte size is

relevant only for the actual transfer of the data; it has no bearing on

representation of the data within a host's file system.

The passive data transfer process (this may be a user-

DTP or a second server-DTP) shall "listen" on the data port prior to sending a

transfer request command. The FTP request command determines the direction

of the data transfer. The server, upon receiving the transfer request, will initiate

the data connection to the port. When the connection is established, the data

transfer begins between DTP's, and the server-PI sends a confirming reply to

the user-PI.

Every FTP implementation must support the use of the

default data ports, and only the USER-PI can initiate a change to non-default

ports.

It is possible for the user to specify an alternate data

port by use of the PORT command. The user may want a file dumped on a TAC

line printer or retrieved from a third party host. In the latter case, the user-PI sets

up control connections with both server-PI's. One server is then told (by an FTP

command) to “listen" for a connection which the other will initiate. The user-PI

sends one server-PI a PORT command indicating the data port of the other.

Finally, both are sent the appropriate transfer commands. The exact sequence

of commands and replies sent between the user-controller and the servers is

defined in the Section on FTP Replies.

In general, it is the server's responsibility to maintain the

data connection--to initiate it and to close it. The exception to this is when the

user-DTP is sending the data in a transfer mode that requires the connection to

be closed to indicate EOF. The server MUST close the data connection under

the following conditions:

1. The server has completed sending data in a transfer mode that

requires a close to indicate EOF.

2. The server receives an ABORT command from the user .

3. The port specification is changed by a command from the user.

4. The control connection is closed legally or otherwise.

5. An irrecoverable error condition occurs.

Otherwise the close is a server option, the exercise of

which the server must indicate to the user-process by either a 250 or 226 reply

only.

DEFAULT DATA CONNECTION PORTS :

All FTP implementations must support use of the default

data connection ports, and only the User-PI may initiate the use of non-default

ports.

Negotiating Non-Default Data Ports:The User-PI may

specify a non-default user side data port with the PORT command. The User-PI

may request the server side to identify a non-default server side data port with

the PASV command. Since a connection is defined by the pair of addresses,

either of these actions is enough to get a different data connection, still it is

permitted to do both commands to use new ports on both ends of the data

connection.

Reuse of the Data Connection: When using the stream

mode of data transfer the end of the file must be indicated by closing the

connection. This causes a problem if multiple files are to be transfered in the

session, due to need for TCP to hold the connection record for a time out period

to guarantee the reliable communication. Thus the connection can not be

reopened at once.

There are two solutions to this problem. The first is to

negotiate a non-default port. The second is to use another transfer mode.

FILE TRANSFER FUNCTIONS

The communication channel from the user-PI to the

server-PI is established as a TCP connection from the user to the standard

server port. The user protocol interpreter is responsible for sending FTP

commands and interpreting the replies received; the server-PI interprets

commands, sends replies and directs its DTP to set up the data connection and

transfer the data. If the second party to the data transfer (the passive transfer

process) is the user-DTP, then it is governed through the internal protocol of the

user-FTP host; if it is a second server-DTP, then it is governed by its PI on

command from the user-PI. The FTP replies are discussed in the next section.

In the description of a few of the commands in this section, it is helpful to be

explicit about the possible replies.

FTP COMMANDS:

ACCESS CONTROL COMMANDS

USER NAME

The argument field is a string identifying the user. The

user identification is that which is required by the server for access to its file

system. This command will normally be the first command transmitted by the

user after the control connections are made (some servers may require this).

Additional identification information in the form of a password and/or an account

command may also be required by some servers. Servers may allow a new

USER command to be entered at any point in order to change the access

control and/or accounting information. This has the effect of flushing any user,

password, and account information already supplied and beginning the login

sequence again. All transfer parameters are unchanged and any file transfer

in progress is completed under the old access control parameters.

PASSWORD

The argument field is a Telnet string specifying the user's

password. This command must be immediately preceded by the user name

command, and, for some sites, completes the user's identification for access

control. Since password information is quite sensitive, it is desirable in

general to "mask" it or suppress typeout. It appears that the server has no

foolproof way to achieve this. It is therefore the responsibility of the user-FTP

process to hide the sensitive password information.

CHANGE WORKING DIRECTORY

This command allows the user to work with a different

directory or dataset for file storage or retrieval without altering his login or

accounting information. Transfer parameters are similarly unchanged. The

argument is a pathname specifying a directory or other system dependent file

group designator.

TRANSFER PARAMETER COMMANDS

All data transfer parameters have default values, and the

commands specifying data transfer parameters are required only if the default

parameter values are to be changed. The default value is the last specified

value, or if no value has been specified, the standard default value is as stated

here. This implies that the server must "remember" the applicable default

values. The commands may be in any order except that they must precede the

FTP service request. The following commands specify data transfer

parameters:

DATA PORT

The argument is a HOST-PORT specification for the data

port to be used in data connection. There are defaults for both the user and

server data ports, and under normal circumstances this command and its reply

are not needed. If this command is used, the argument is the concatenation of a

32-bit internet host address and a 16-bit TCP port address. This address

information is broken into 8-bit fields and the value of each field is transmitted as

a decimal number (in character string representation). The fields are separated

by commas.

DELETE

This command causes the file specified in the pathname to

be deleted at the server site. If an extra level of protection is desired (such as

the query, "Do you really wish to delete?"), it should be provided by the user-

FTP process.

REMOVE DIRECTORY

This command causes the directory specified in the

pathname to be removed as a directory (if the pathname is absolute) or as a

subdirectory of the current working directory (if the pathname is relative

MAKE DIRECTORY

This command causes the directory specified in the

pathname to be created as a directory (if the pathname is absolute) or as a

subdirectory of the current working directory (if the pathname is relative). See

Appendix II.

PRINT WORKING DIRECTORY

This command causes the name of the current working

directory to be returned in the reply.

LIST

This command causes a list to be sent from the server to

the passive DTP. If the pathname specifies a directory or other group of files,

the server should transfer a list of files in the specified directory. If the pathname

specifies a file then the server should send current information on the file. A null

argument implies the user's current working or default directory. The data

transfer is over the data connection in type ASCII or type EBCDIC. (The

user must ensure that the TYPE is appropriately ASCII or EBCDIC). Since the

information on a file may vary widely from system to system, this information

may be hard to use automatically in a program, but may be quite useful to a

human user.

3.3.3 HTTP Module:

INTRODUCTION :

The Hypertext Transfer Protocol (HTTP) is an

application-level protocol for distributed, collaborative, hypermedia information

systems. HTTP has been in use by the World-Wide Web global information

initiative since 1990. The first version of HTTP, referred to as HTTP/0.9, was a

simple protocol for raw data transfer across the Internet. HTTP/1.0, as defined by

RFC 1945 , improved the protocol by allowing messages to be in the format of

MIME-like messages, containing meta information about the data transferred and

modifiers on the request/response semantics. However, HTTP/1.0 does not

sufficiently take into consideration the effects of hierarchical proxies, caching, the

need for persistent connections, or virtual hosts. In addition, the proliferation of

incompletely implemented applications calling themselves "HTTP/1.0" has

necessitated a protocol version change in order for two communicating

applications to determine each other's true capabilities.

This specification defines the protocol referred to as

"HTTP/1.1". This protocol includes more stringent requirements than HTTP/1.0 in

order to ensure reliable implementation of its features.

Messages are passed in a format similar to that used by

Internet mail as defined by the Multipurpose Internet Mail Extensions (MIME) .

HTTP is also used as a generic protocol for communication between user agents

and proxies/gateways to other Internet systems, including those supported by the

SMTP , NNTP , FTP , Gopher , and WAIS protocols.

ANALYSIS

This specification uses a number of terms to refer to the roles played by

participants in, and objects of, the HTTP communication.

connection

A transport layer virtual circuit established between two programs for the purpose

of communication.

message

The basic unit of HTTP communication, consisting of a structured sequence of

octets and transmitted via the connection.

request

An HTTP request message.

response

An HTTP response message.

resource

A network data object or service that can be identified by a URI. Resources may

be available in multiple representations (e.g. multiple languages, data formats,

size, and resolutions) or vary in other ways.

entity

The information transferred as the payload of a request or

response. An entity consists of metainformation in the form of entity-

header fields and content in the form of an entity-body.

representation

An entity included with a response that is subject to content negotiation.

content negotiation

The mechanism for selecting the appropriate representation when servicing a

request. The representation of entities in any response can be negotiated

(including error responses).

variant

A resource may have one, or more than one, representation(s) associated with it

at any given instant. Each of these representations is termed a `varriant'. Use of

the term `variant' does not necessarily imply that the resource is subject to

content negotiation.

client

A program that establishes connections for the purpose of sending requests.

user agent

The client which initiates a request. These are often browsers, editors, spiders

(web-traversing robots), or other end user tools.

server

An application program that accepts connections in order to service requests by

sending back responses.

origin server

The server on which a given resource resides or is to be created

.

proxy

An intermediary program which acts as both a server and a client for the purpose

of making requests on behalf of other clients. Requests are serviced internally or

by passing them on, with possible translation, to other servers .

gateway

A server which acts as an intermediary for some other server. Unlike a proxy, a

gateway receives requests as if it were the origin server for the requested

resource; the requesting client may not be aware that it is communicating with a

gateway.

first-hand

A response is first-hand if it comes directly and without unnecessary delay from

the origin server, perhaps via one or more proxies. A response is also first-hand

if its validity has just been checked directly with the origin server.

explicit expiration time

The time at which the origin server intends that an entity should no longer be

returned by a cache without further validation.

upstream/downstream

Upstream and downstream describe the flow of a message: all messages flow

from upstream to downstream.

Inbound/outbound

Inbound and outbound refer to the request and response paths for messages:

"inbound" means "traveling toward the origin server", and "outbound" means

"traveling toward the user agent"

Overall operation:

The HTTP protocol is a request/response protocol. A client

sends request to the server in the form of a request method, URI, and protocol

version, followed by a MIME-like message containing request modifiers, client

information, and possible body content over a connection with a server. The

server responds with a status line, including the message's protocol version and

a success or error code, followed by a MIME-like message containing server

information, entity metainformation, and possible entity-body content.

Most HTTP communication is initiated by a user agent and

consists of a request to be applied to a resource on some origin server. In the

simplest case, this may be accomplished via a single connection (v) between the

user agent (UA) and the origin server (O).

A more complicated situation occurs when one or more

intermediaries are present in the request/response chain. There are three

common forms of intermediary: proxy, gateway, and tunnel. A proxy is a

forwarding agent, receiving requests for a URI in its absolute form, rewriting all or

part of the message, and forwarding the reformatted request toward the server

identified by the URI. A gateway is a receiving agent, acting as a layer above

some other server(s) and, if necessary, translating the requests to the underlying

server's protocol. A tunnel acts as a relay point between two connections without

changing the messages; tunnels are used when the communication needs to

pass through an intermediary (such as a firewall) even when the intermediary

cannot understand the contents of the messages.

Three intermediaries (A, B, and C) between the user

agent and origin server. A request or response message that travels the whole

Requet chain

UA

O

Response chain

chain will pass through four separate connections. This distinction is important

because some HTTP communication options may apply only to the connection

with the nearest, non-tunnel neighbor, only to the end-points of the chain, or to all

connections along the chain. Although the diagram is linear, each participant may

be engaged in multiple, simultaneous communications. For example, B may be

receiving requests from many clients other than A, and/or forwarding requests to

servers other than C, at the same time that it is handling A's request.

Protocol Parameters:

i) Http URL

URL is an acronym for Uniform Resource Locator and is a reference (an

address) to a resource on the Internet.

The following is an example of a URL which addresses the Java Web site

hosted by Sun Microsystems:

As in the previous diagram, a URL has two main components:

Protocol identifier

Resource name

Note that the protocol identifier and the resource name are

separated by a colon and two forward slashes. The protocol identifier indicates

the name of the protocol to be used to fetch the resource. The example uses the

Hypertext Transfer Protocol (HTTP), which is typically used to serve up hypertext

documents. HTTP is just one of many different protocols used to access different

types of resources on the net. Other protocols include File Transfer Protocol

(FTP), Gopher, File, and News.

The resource name is the complete

address to the resource. The format of the resource name depends

entirely on the protocol used, but for many protocols, including HTTP,

the resource name contains one or more of the components listed in the

following table:

Host Name The name of the machine on which the resource lives.

Filename The pathname to the file on the machine.

Port

Number The port number to which to connect (typically optional).

Reference A reference to a named anchor within a resource that usually

identifies a specific location within a file (typically optional).

The "http" scheme is used to locate network resources

via the HTTP protocol. This section defines the scheme-specific syntax and

semantics for http URLs.

http_URL = "http:" "//" host [ ":" port ] [ abs_path [ "?" query ]]

If the port is empty or not given, port 80 is assumed.

The semantics are that the identified resource is located at the server listening

for TCP connections on that port of that host, and the Request-URI for the

resource is abs_path . The use of IP addresses in URLs SHOULD be avoided

whenever possible . If the abs_path is not present in the URL, it MUST be given

as "/" when used as a Request-URI for a resource . If a proxy receives a host

name which is not a fully qualified domain name, it MAY add its domain to the

host name it received. If a proxy receives a fully qualified domain name, the

proxy MUST NOT change the host name.

4.SYSTEM DESIGN

Software design is the technical heart of the software engineering process. Here whatever the software requirements specified in the analysis phases are to be translated into a representation of software.

4.1 DESIGN METHODOLOGY

Software design is a process through which requirements are

translated into representation of software. Initially the representation depicts a

holistic view of software. Subsequent refinement leads to a design representation

that is very close to source code.

From a project management point of view, software design is

conducted in two steps.

These two steps are:

Preliminary Design

Detailed Design

The preliminary design is concerned with the transformation of requirements into data and software architecture. Detailed design focuses on architectural representation for software. The Object-Oriented design is applied for the system.

4.2 DESIGN OBJECTIVE

The System is designed with the following properties.

a) Verifiability:

The design is concerned with how easily the correctness of the design can be argued.

b) Tracability:

This property can aid design verification. It requires all design

elements to be traceable to the requirements.

c) Completeness:

All the different components of the design i.e. relevant data

structures, modules, external interfaces and module interconnections are

specified

d) Efficiency:

It is concerned with the proper use of scarce resources by the

system.

e) Simplicity and Understand ability:

A simple design is likely to have a high degree of independence

between modules. During maintenance, the maintainer has a thorough

understanding of the different modules of the system, how the modules are

interconnected, how modifying one will affect the other, should the modification

be undertaken.

4.3 OBJECT ORIENTED DESIGN

Design is concerned with the mapping of objects in

the problem space into objects in the solution space and creating an overall

structure and computational models of the system. The object oriented design

approach may involve the following steps.

Review of the Objects Created in the Analysis Phase:

The main objective of this review exercise is to refine the objects

in terms of the attributes and operations and to identify other objects that are

solution specific.

Specification of Class dependencies:

Analysis of the relationships between the classes is central to

the structure of a system. The major relationships that are important in the

context of design are:

Inheritance relationships

User relationships

The class dependencies in this project have a relationship of

multilevel inheritance.

Organization of Class Hierarchies:

Organization of class hierarchies involves identification of

common attributes and functions among a group of related classes and then

combining them to form new class.

Design of Classes:

This step involves looking at the complete details that each

class represents. The important issue is to decide what functions are to be

provided.

Design of Member Functions:

The member functions define the operations that are performed

on the object’s data.

4.4 Modular Design

The design of a project can be effectively done by using the Modular Design

approach. In this approach we follow the method of dividing the project into

several modules recursively until each module can be handled individually

effectively, after designing such modules they are combined accordingly to get

the final output. This approach makes the designer to have good control over his

project and he can easily debug the project to find out the errors during the

course of the design of his project. He can modify the project easily so that the

project can be updated to any new requirement in the future. This lead us to use

this approach to design our project effectively. Our project is basically divided

into 3 modules.

1. HTTP Module

2. FTP Module

3. E-cabinet Module

HTTP ModuleThis module provides the basic navigator function to navigate over

the “web pages”. Also it consists of several sub-modules, which provides all the basic functionalities that we normally encountered in “Internet Explorer”. Accordingly this module consists of several sub-modules, which are

History ModuleFavorite ModuleView Source ModuleMailHandler ModulePrint Module

FTP ModuleThis Module makes it possible to communicate with the FTP server.

Once we connect to the FTP server we can perform the basic “Uploading” and “Downloading” operations with FTP server.

E-Cabinet ModuleThis module provides the facility to store text files in the server

address space in the intended user’s login. This module is implemented

using JAVA

“Socket “ and “Server Socket” classes.

4.5 Data Flow Diagrams

4.5.1DFD’s FOR HTTP Module

Context Level DFD of HTTP Handler

URL AddressHTTPHandler

Requested Page will be displayed

URL Address

HTTPHandler History

Previous Page

Next Page

View Source

Favorites

Requested page Will be Displayed

HTML Document will be opened

Level- I DFD of HTTP Handler

Level –ii DFD of HTTP Previous Page

URL AddressPreviousHTTP

Handler

Previous Page will be displayed

URL Address HTTPHandler

NEXT

Next page will be displayed

Request for Previous page

Request for next page

Retrieve Previous page from History

Retrieve Next page from History

Add to Favorites

Level –ii DFD of HTTP Next Page

URL Address HTTPHandler

Favorites

Add to Favorites

Best Links

Favorites

Add to Favorites

Best Links

The Current Page will be added to Favorites

Selected Best link Page will be displayed

List Of Best Links

Level – ii DFD of HTTP Favorites

URL AddressHTTP Handler History

List of Pages that U had visited will be displayed

OPEN

DELETE

History OPEN

The selected Page will be Displayed

DELETE

The Page will be Deleted from List

Level-ii DFD for History Module

Level –ii DFD of HTTP View Source module

URL AddressHTTP Handler

View Source

Open an URL Connection with the Requested URL

Retrieve the HTML file using Input Stream Object

URL Address

HTTPHandler

View Source

Source code of the URL will be displayed

Level –iii DFD of HTTP View Source module

4.5.2 DFD’s for FTP Module

Context-Level DFD of FTP Handler

The Source code of the requested page will be displayed

Server InformationConnection Establishment with server

Processing the user request

Connection with server FTP Handler

UP Load

DOWN Load

MAKE Directory

DELETE Directory

DELETE File

Processing the user request

LEVEL –I DFD of FTP Handler

Level –ii DFD of FTP Upload function

Level – ii DFD of FTP Download Function

FTP Handler

Upload File

Select the File U want to upload

Selected File will be uploaded

FTP Handler Download

File

Select the file U want to download

Selected File will be downloaded

User Request

User Request

Level –ii DFD For “MAKING Directory” Function

FTP Handler

MAKE Directory

Server Side

Client or Local Side

Directory will be created

Directory will be Created

FTP Handler

DELETE Directory

Server Side

Directory will be deleted

User Request

User Request

myFtp.mkdir (dirName)

dir.mkdir()

myFtp.rmdir(dirname)

Level - ii DFD for FTP DELETE Directory Function

Level – ii DFD for FTP RENAME Function

Client or Local Side

Directory will be deleted

FTP Handler

Rename

Server Side

Client Side

Selected directory will be renamed

Selected directory will be renamed

User Request

dir.delete()

OldFileName.renameTo (new Filename)

myFtp.mv(oldname,newName)

4.6 FLOW Charts

4.6.1 HTTP Module

START

HTTP Handler

Requested page will be displayed

Valid URL ?

YESWarning message will be displayed

NO

PREVIOUSPAGE

NEXT PAGE ADD to Favorites

VIEW Source

URL Address Return

MAIL Handler

PREVIOUS PAGE

USER request

HTTP Handler

Retrieve Previous page from History

Previous page exists ?

Display the Page

Display the Current Page

YES

NO

PREV

NEXT ADF VIEWS

MAH

PREV

NEXT PAGE

USER request

HTTP Handler

Retrieve Next page from History

Next page exists?

Display the Page

Display the Current Page

YES

NO

NEXT

Return

Return

ADF

Current URL address

IF it is not already added ?

NO

YES

The URL address will not be added

The URL address will be added

Return

VIEWS

URL address

If the URL is valid ?

YES

NO

Warning message will be displayed

HTML document of the URL will be displayed

Return

4.6.2 FTP Module

MAH

Source address,Destination address,Message

User input

MAIL Handler

Connection with SMTP mail server

Connection Established?

YES

NOMessage may not be send

Message will be sent Return

START

Information for Connection

Connection with Requested Server

Connection Established?

NONot valid Information

YES

USER request

UP LOAD the File

DOWN Load the File

MAKE Directory

DELETE Directory

MAKE Directory

UP

DWN MKD DELRNM

MKD

DELETE File

RENAME File

DEF

Return

Select the side where u want to make Directory

Client Side? Enter the Directory Name

Directory will be created

If the Directory already exists?

Directory will not be created

YES

NO

YES

Error Messg will be displayed

Enter the Directory Name

Directory will be created

Directory will not be created

NO

YES

Error Messg will be displayed

If the Directory already exists?

NO

Return