Notes Web and Database Technology (WDT) (Web section)
9 views 0 purchase
Course
Web and Database Technology (CSE1500)
Institution
Technische Universiteit Delft (TU Delft)
Notes Web section Web and Database Technology (WDT) Year 1 (2021/2022) Computer Science and Engineering at TU Delft Topics 1 HTTP 2 HTML 3 JavaScript 4 N 1 5 CSS 6 N 2 7 Sessions et al 8 Web security
<port> optional
80 (this is the default port when no port is specified)
3000
5000
...and any other integer from 0 to 65535
<path> optional
(login, calendar/january/31)
...it's a path, you know what a path is
<query_params> optional
(username=kevin, username=kevin&token=fdfa8e7cc4b3)
key=value pairs separated by &, comes after the ?
Usually used for sending data in a GET request since GET requests can't send
content in the body
Examples
# Ordinary URL, note the <port> is missing, so it defaults to 80
https://google.com
# Pointing to computer's own address, note the port is specified as 3000
# Also note it has a query string with some data
http://localhost:3000/register?username=kevin&password=yeet
,HTTP/HTTPS
HTTPS is HTTP with encryption. The difference between the two protocols is that HTTPS
encrypts normal HTTP requests and responses. As a result, HTTPS is far more secure than
HTTP.
Requests
You should always think of requests as <method> <path>. The client/browser always makes
the request, the server responds.
Long Polling
Long polling emulates a push mechanism that is missing in HTTP/1.1: the client sends an
HTTP request, the server holds the request open until new data is available before sending
its HTTP response. Once the response is sent, the client immediately sends another HTTP
request that is kept open.
Methods
HEAD - subset of GET, only gives back headers (general information, like connection and
cache-control) and not actual content
GET - retrieves data from server
POST - sends data to server
PUT - updates data on server
DELETE - removes data from server
Before using a method, we connect to either telnet or openssl, always start with trying telnet.
Connecting to telnet
telnet *host* 80
80 is the port, host would be the website
Connecting to openssl
openssl s_client -crlf -connect *host*:443
Openssl needs to be used when we want to access something that uses https.
443 is the port for using openssl, host is the website (like tudelft.nl)
, HEAD/GET request
For example, if you want the data on the following page tudelft.nl/wdt, your request would be
GET /wdt HTTP/1.1
host:tudelft.nl
*press enter twice*
So the type of request, the path, then which HTTP you’re using (always 1.1), and then the
host (the website). If we just want the homepage, the path would just be /.
PUT request
For example, if you want to modify a resource, and update it to ‘Hello World!’, you’d do
PUT /put HTTP/1.1
host:tudelft.nl
Content-type:text/plain
Content-length:12
*enter*
Hello World!
*enter*
If you’d make the content length smaller, it’d give a 400 bad request error. If you’d make
content length larger, it’d wait until you’ve reached that larger number by counting your
enters/new lines as characters.
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller liekesanders. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $5.23. You're not tied to anything after your purchase.