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Abhay Kant JhaEmail
akjha14@rediffmail.com
| Profile: I am an Engineering graduate from Bangalore university, India.
I have worked in Structural design firm for 5 years.
I know JAVA Technologies, ORACLE, COBOL in Computers.
I am doing MBA from Tarleton State University.
I want to specialise in Finance.Prof. Ashay Dharwadker's Courses (1): | Course | Semester | Grade | | | Computer Networks | Spring 2004 | View | |
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Seminar ID: 51
Course: Computer Networks
Topic: Client - Server Application
| Description: I demonstrated a Client - Server chat application that I designed using Java. The Client and the Server are both run from the command prompt. During the seminar the application was run on the local host IP ADDRESS 127.0.0.1. However, the application can be run simultaneously on many hosts over a LAN.
The Java code is given below in my research note.
|
Research Note ID: 53
Course: Computer Networks
Topic: Java Code for the Client Server Application
| Description:
// Server Application
===========
import java.net.*;
import java.io.*;
public class EchoServer
{
public static void main(String[] args) throws IOException
{
ServerSocket serverSocket = null;
try{
serverSocket = new ServerSocket(95);
}
catch (IOException e)
{
System.err.println("Couldn't listen to port:80.");
System.exit(1);
}
Socket clientSocket = null;
try{
clientSocket = serverSocket.accept();
System.out.println("Connected to " + clientSocket);
}
catch (IOException e)
{System.err.println("Accept failed");
System.exit(1);
}
PrintWriter out = new PrintWriter(clientSocket.getOutputStream(), true);
BufferedReader in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
String inputLine;
BufferedReader stdin = new BufferedReader(new InputStreamReader(System.in));
System.out.println("Enter data in server");
while((inputLine = stdin.readLine()) != null)
{
out.println(inputLine);
}
out.close();
in.close();
stdin.close();
clientSocket.close();
serverSocket.close();
}
}
==//Client Application=================
import java.net.*;
import java.io.*;
public class EchoClient
{
public static void main(String[] args) throws IOException
{
Socket echoSocket = null;
BufferedReader in = null;
try{
echoSocket = new Socket(InetAddress.getLocalHost(),95);
in = new BufferedReader(new InputStreamReader(echoSocket.getInputStream()));
}
catch (UnknownHostException e)
{
System.err.println("Don't know about host");
System.exit(1);
}
catch (IOException e)
{
System.err.println("Couldn't get I/O for the connection");
System.exit(1);
}
String userInput;
while ((userInput = in.readLine()) != null)
{
System.out.println(userInput);
}
in.close();
echoSocket.close();
}
}
|
Research Note ID: 54
Course: Computer Networks
Topic: Hyper Text Transport Protocol
| | Description: HTTP (HyperText Transfer Protocol).
"Enquire Within Upon Everything" — a nifty little computer program written nearly 20 years ago by a lowly software consultant named Tim Berners-Lee. Who knew then that from this modest hack would flow the civilization-altering, millionaire-spawning, information suckhole known as the World Wide Web?
Unlike so many of the inventions that have moved the world, this one truly was the work of one man. Thomas Edison got credit for the light bulb, but he had dozens of people in his lab working on it. William Shockley may have fathered the transistor, but two of his research scientists actually built it. And if there ever was a thing that was made by committee, the Internet — with its protocols and packet switching — is it. But the World Wide Web is Berners-Lee's alone. He designed it. He loosed it on the world. And he more than anyone else has fought to keep it open, nonproprietary and free.
It started, of all places, in the Swiss Alps. The year was 1980. Berners-Lee, doing a six-month stint as a software engineer at CERN, the European Laboratory for Particle Physics, in Geneva, was noodling around with a way to organize his far-flung notes. He had always been interested in programs that dealt with information in a "brain-like way" but that could improve upon that occasionally memory-constrained organ. So he devised a piece of software that could, as he put it, keep "track of all the random associations one comes across in real life and brains are supposed to be so good at remembering but sometimes mine wouldn't." He called it Enquire, short for Enquire Within Upon Everything, a Victorian-era encyclopedia he remembered from childhood.
Building on ideas that were current in software design at the time, Berners-Lee fashioned a kind of "hypertext" notebook. Words in a document could be "linked" to other files on Berners-Lee's computer; he could follow a link by number (there was no mouse to click back then) and automatically pull up its related document. It worked splendidly in its solipsistic, Only-On-My-Computer way.
But what if he wanted to add stuff that resided on someone else's computer? First he would need that person's permission, and then he would have to do the dreary work of adding the new material to a central database. An even better solution would be to open up his document — and his computer — to everyone and allow them to link their stuff to his. He could limit access to his colleagues at CERN, but why stop there? Open it up to scientists everywhere! Let it span the networks! In Berners-Lee's scheme there would be no central manager, no central database and no scaling problems. The thing could grow like the Internet itself, open-ended and infinite. "One had to be able to jump," he later wrote, "from software documentation to a list of people to a phone book to an organizational chart to whatever."
So he cobbled together a relatively easy-to-learn coding system — HTML (HyperText Mark-up Language) — that has come to be the lingua franca of the Web; it's the way Web-content creators put those little colored, underlined links in their text, add images and so on. He designed an addressing scheme that gave each Web page a unique location, or url (universal resource locator). And he hacked a set of rules that permitted these documents to be linked together on computers across the Internet. He called that set of rules HTTP (HyperText Transfer Protocol).
And on the seventh day, Berners-Lee cobbled together the World Wide Web's first (but not the last) browser, which allowed users anywhere to view his creation on their computer screen. In 1991 the World Wide Web debuted, instantly bringing order and clarity to the chaos that was cyberspace. From that moment on, the Web and the Internet grew as one, often at exponential rates. Within five years, the number of Internet users jumped from 600,000 to 40 million. At one point, it was doubling every 53 days.
Raised in London in the 1960s, Berners-Lee was the quintessential child of the computer age. His parents met while working on the Ferranti Mark I, the first computer sold commercially. They taught him to think unconventionally; he'd play games over the breakfast table with imaginary numbers (what's the square root of minus 4?). He made pretend computers out of cardboard boxes and five-hole paper tape and fell in love with electronics. Later, at Oxford, he built his own working electronic computer out of spare parts and a TV set. He also studied physics, which he thought would be a lovely compromise between math and electronics. "Physics was fun," he recalls. "And in fact a good preparation for creating a global system."
It's hard to overstate the impact of the global system he created. It's almost Gutenbergian. He took a powerful communications system that only the elite could use and turned it into a mass medium. "If this were a traditional science, Berners-Lee would win a Nobel Prize," Eric Schmidt, CEO of Novell, once told the New York Times. "What he's done is that significant."
You'd think he would have at least got rich; he had plenty of opportunities. But at every juncture, Berners-Lee chose the nonprofit road, both for himself and his creation. Marc Andreessen, who helped write the first popular Web browser, Mosaic — which, unlike the master's browser, put images and text in the same place, like pages in a magazine — went on to co-found Netscape and become one of the Web's first millionaires. Berners-Lee, by contrast, headed off in 1994 to an administrative and academic life at the Massachusetts Institute of Technology. From a sparse office at M.I.T., he directs the W3 Consortium, the standard-setting body that helps Netscape, Microsoft and anyone else agree on openly published protocols rather than hold one another back with proprietary technology. The rest of the world may be trying to cash in on the Web's phenomenal growth, but Berners-Lee is content to labor quietly in the background, ensuring that all of us can continue, well into the next century, to Enquire Within Upon Anything.
The most widely used part of the Internet is the World Wide Web (often abbreviated "WWW" or called "the Web"). Its outstanding feature is hypertext, a method of instant cross-referencing. In most Web sites, certain words or phrases appear in text of a different color than the rest; often this text is also underlined. When you select one of these words or phrases, you will be transferred to a site relevant to the word or phrase. Sometimes there are buttons, images, or portions of images that are "clickable." If you move the pointer over a spot on a Web site and the pointer changes into a hand, this indicates that you can click and be transferred to another site.
The Web's protocol inventor is Tim Berners-Lee who co-founded The World Wide Web Consortium who foster the development of Hypertext Transport Protocol (HTTP) that your Web browser and all Web servers use, plus Hypertext Markup Language (HTML), and other Web standards. All the Net's addresses and domain names are controlled by an organization called InterNIC.
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Last updated on Friday, 9th April 2004, 06:29:05 PM.
Prof. Ashay Dharwadker
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