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A higher level approach

URL programming occurs at a higher level than socket programming, and in theory represents some very powerful ideas. The powerful ideas represented bythe advanced features of the URL class require an understanding of the development of protocol handlers and content handlers. I discussed this in somedetail in an earlier module titled Java4620: General Information , and won't repeat that discussion here.

A mundane alternative

In addition to supporting the advanced concepts discussed in the earlier module, theURL class also provides a relatively mundane alternative way to connect one computer to another and transfer data on a stream basis. This module isprimarily based on this capability.

Discussion and sample code

I will explain the programs named Java4640a and Java4640d in fragments. Complete listings of both programs are provided in Listing 8 and Listing 9 .

The program Java4640a

This program exercises four of the constructors and six of the methods of the URL class.

The program also illustrates the use of the URLEncoder class to convert a string containing spaces and other such characters into a UTF-8encoded string format.

Screen output from the program named Java4640a

The output from the program is shown in Figure 2 . I will refer to portions of this output while discussing the program.

Figure 2 - Screen output from the program named Java4640a.
Use simple string constructor for host URL http www.austincc.edu -1 nullhttp://www.austincc.edu Use simple string constructor for host plus filehttp www.austincc.edu -1 /baldwin null http://www.austincc.edu/baldwinUse strings for protocol, host, and file http www.austincc.edu -1 /baldwin nullhttp://www.austincc.edu/baldwin Use strings for protocol host, and fileand int for port http www.austincc.edu 80 /baldwin nullhttp://www.austincc.edu:80/baldwin Construct absolute URL from host URL and relative URLhttp www.austincc.edu -1 /baldwin/Index.html null http://www.austincc.edu/baldwin/Index.htmlNow use URLEncoder to create UTF-8 encoded String http://space .tilde~.plus+.comhttp%3A%2F%2Fspace+.tilde%7E.plus%2B.com

The method named display

The code in Listing 1 is a method named display that I wrote to illustrate some of the methods of the URLclass, and also to serve the practical needs of displaying information contained in a URL object.

Listing 1 - The method named display.
void display(URL url){//method to display parts of URL System.out.print(url.getProtocol() + " ");System.out.print(url.getHost() + " "); System.out.print(url.getPort() + " ");System.out.print(url.getFile() + " "); System.out.println(url.getRef());//Now display entire URL as a string.System.out.println(url.toString()); System.out.println();}//end display

This method receives a reference to a URL object as a parameter and displays its component parts separated by space characters. Then it uses the overridden toString method of the URL class to display the contents of theURL object as a single String object.

The parts of the URL

Questions & Answers

what is math number
Tric Reply
x-2y+3z=-3 2x-y+z=7 -x+3y-z=6
Sidiki Reply
Need help solving this problem (2/7)^-2
Simone Reply
x+2y-z=7
Sidiki
what is the coefficient of -4×
Mehri Reply
-1
Shedrak
the operation * is x * y =x + y/ 1+(x × y) show if the operation is commutative if x × y is not equal to -1
Alfred Reply
An investment account was opened with an initial deposit of $9,600 and earns 7.4% interest, compounded continuously. How much will the account be worth after 15 years?
Kala Reply
lim x to infinity e^1-e^-1/log(1+x)
given eccentricity and a point find the equiation
Moses Reply
12, 17, 22.... 25th term
Alexandra Reply
12, 17, 22.... 25th term
Akash
College algebra is really hard?
Shirleen Reply
Absolutely, for me. My problems with math started in First grade...involving a nun Sister Anastasia, bad vision, talking & getting expelled from Catholic school. When it comes to math I just can't focus and all I can hear is our family silverware banging and clanging on the pink Formica table.
Carole
I'm 13 and I understand it great
AJ
I am 1 year old but I can do it! 1+1=2 proof very hard for me though.
Atone
hi
Adu
Not really they are just easy concepts which can be understood if you have great basics. I am 14 I understood them easily.
Vedant
find the 15th term of the geometric sequince whose first is 18 and last term of 387
Jerwin Reply
I know this work
salma
The given of f(x=x-2. then what is the value of this f(3) 5f(x+1)
virgelyn Reply
hmm well what is the answer
Abhi
If f(x) = x-2 then, f(3) when 5f(x+1) 5((3-2)+1) 5(1+1) 5(2) 10
Augustine
how do they get the third part x = (32)5/4
kinnecy Reply
make 5/4 into a mixed number, make that a decimal, and then multiply 32 by the decimal 5/4 turns out to be
AJ
how
Sheref
can someone help me with some logarithmic and exponential equations.
Jeffrey Reply
sure. what is your question?
ninjadapaul
20/(×-6^2)
Salomon
okay, so you have 6 raised to the power of 2. what is that part of your answer
ninjadapaul
I don't understand what the A with approx sign and the boxed x mean
ninjadapaul
it think it's written 20/(X-6)^2 so it's 20 divided by X-6 squared
Salomon
I'm not sure why it wrote it the other way
Salomon
I got X =-6
Salomon
ok. so take the square root of both sides, now you have plus or minus the square root of 20= x-6
ninjadapaul
oops. ignore that.
ninjadapaul
so you not have an equal sign anywhere in the original equation?
ninjadapaul
hmm
Abhi
is it a question of log
Abhi
🤔.
Abhi
I rally confuse this number And equations too I need exactly help
salma
But this is not salma it's Faiza live in lousvile Ky I garbage this so I am going collage with JCTC that the of the collage thank you my friends
salma
Commplementary angles
Idrissa Reply
hello
Sherica
im all ears I need to learn
Sherica
right! what he said ⤴⤴⤴
Tamia
hii
Uday
hi
salma
hi
Ayuba
Hello
opoku
hi
Ali
greetings from Iran
Ali
salut. from Algeria
Bach
hi
Nharnhar
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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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