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Then the program closes the socket and terminates.

Simple browser program

The next program is an extremely simple web browser program. More correctly, the next program is a simple HTTP client implemented using sockets. A completelisting of the program is provided in Listing 14 .

The program implements just enough of the HTTP protocol to make it capable of getting a file froman HTTP server. Considerably more programming effort would be required to turn it into a useful browser.

Beginning of the program named Java4660c

As shown in Listing 8 , the program begins by defining the name of a server and the number of the HTTP port on that server. Although the standard portnumber for HTTP servers is port 80, this program is written to access a Tomcat server as localhost using port 8080.

Listing 8 - Beginning of the program named Java4660c.
import java.net.*; import java.io.*;class Java4660c{ public static void main(String[]args){ String server = "localhost";int port = 8080; //http port on localhost try{//Get a socket, connected to the specified server // on the specified port.Socket socket = new Socket(server,port);

Then the program opens a socket to the specified server on the specified port.

Create input and output streams

As shown in Listing 9 , the program creates input and output stream objects for transferring data between the client and the server .

Listing 9 - Create input and output streams.
//Get an input stream from the socket BufferedReader inputStream =new BufferedReader(new InputStreamReader( socket.getInputStream()));//Get an output stream to the socket. Note // that this stream will autoflush.PrintWriter outputStream = new PrintWriter(new OutputStreamWriter(socket.getOutputStream()),true);

The output stream will autoflush , which is critical. If the output stream isn't flushed, the server will not respondproperly. (Presumably it may not receive all of the data until the stream is flushed.)

Send a GET command

The HTTP protocol provides several different commands or requests that the client can send to the server. This program implements only the GET command. This is a request by the client to find and download a specified file.

Then, as shown in Listing 10 , acting as an HTTP client, the program sends a GET command to the server specifying a particular path and file name. The GET command is part of the HTTP application protocol.

Listing 10 - Send a GET command.
outputStream.println("GET /Java4570b.jsp");

Fetch and send

This causes the server to attempt to fetch the specified file and send it to the client. If the server is being properly supported on the specific port, itwill send something, although that something could be an error message.

Note that the request includes not only the file name, but also the path to that file relative to the directory that the HTTP server software considers tobe the pseudo-root . This is probably not the actual root directory on the server computer, but rather is a logical root.

Questions & Answers

what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
s. Reply
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
China
Cied
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
what is the k.e before it land
Yasmin
what is the function of carbon nanotubes?
Cesar
I'm interested in nanotube
Uday
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
AMJAD
preparation of nanomaterial
Victor Reply
how to synthesize TiO2 nanoparticles by chemical methods
Zubear
what's the program
Jordan
?
Jordan
what chemical
Jordan
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Object-oriented programming (oop) with java. OpenStax CNX. Jun 29, 2016 Download for free at https://legacy.cnx.org/content/col11441/1.201
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