Lecture 5

Question 1

What is HTTP?

Answer 1

HTTP (HyperText Transfer Protocol) is an application layer protocol used for transmitting hypermedia documents such as HTML pages over the internet. It is the foundation of data exchange on the Web and operates on a client-server model

Question 2

What is the basic architecture of HTTP?

Answer 2

HTTP operates on a request/response protocol based on a client/server architecture where clients (e.g., web browsers) send requests to servers, and servers respond with the requested resources​

Question 3

What are the basic features of HTTP communication?

Answer 3

Stateless Protocol: Each request from a client to the server is independent and unrelated to any previous request.
2. Client-Server Architecture: : HTTP operates in a client-server model, where clients (such as web browsers) send requests to servers (such as web servers) for resources, and servers respond with the requested resources.

3. Request-Response Protocol: : Communication between the client and server occurs through a request-response cycle
4. Text-based
5. Methods: HTTP defines several request methods, also known as verbs, that indicate the action to be performed on a resource
6. Status Codes
7. Uniform Resource Identifiers

Question 4

What are HTTP methods and give examples?

Answer 4

HTTP methods specify the action to be performed on a resource. Common methods include GET (retrieve a resource), POST (submit data), PUT (update a resource), DELETE (remove a resource), and more​

Question 5

What are HTTP status codes?

Answer 5

HTTP status codes are three-digit codes included in responses to indicate the outcome of a request. Examples include 200 (success), 404 (not found), and 500 (server error)​

Question 6

What is a Uniform Resource Identifier (URI)?

Answer 6

A URI is used to identify resources on the web, consisting of a scheme (e.g., “http://”), a hostname (e.g., “example.com”), and a path (e.g., “/index.html”)​

Question 7

What are java.net.URL and java.net.HttpURLConnection?

Answer 7

java.net.URL represents a Uniform Resource Locator and provides methods for creating and parsing URLs. java.net.HttpURLConnection extends URLConnection and provides functionality specific to HTTP connections, such as setting request methods and headers

Question 8

What is the HTTP request-response model?

Answer 8

In the HTTP request-response model, a client sends a request (containing a method, headers, and an optional message body) to a server, and the server responds with a status code, headers, and the requested data (if applicable)

Question 9

What are HTTP messages?

Answer 9

HTTP messages are the units of data exchanged in the HTTP protocol. They include requests (from clients to servers) and responses (from servers to clients), each consisting of a start line, headers, and an optional message body

Question 10

What are some common uses of HTTP in Java?

Answer 10

Common uses include web scraping, API integration, building web services, data visualization, file upload/download, and real-time communication using protocols like WebSocket​

Question 11

What is data encryption?

Answer 11

Data encryption is the process of converting data from a readable format to a scrambled piece of information to prevent unauthorized access during transmission. It applies to documents, files, messages, or any other form of communication over a network​

Question 12

What are symmetric and asymmetric encryption?

Answer 12

Symmetric encryption uses the same key for encryption and decryption, while asymmetric encryption uses a pair of keys (public and private) where one key encrypts and the other decrypts the data

Question 12

What is web scraping with Java using JSoup?

Answer 12

Web scraping with Java using JSoup involves fetching data from websites by sending HTTP requests to URLs and parsing the HTML content returned. JSoup is a Java library used for working with HTML and XML files

Question 13

Why is data encryption important?

Answer 13

Data encryption ensures authentication, privacy, and security. It helps protect against data breaches and unauthorized access during data transmission and storage​

Question 14

What is the AES encryption algorithm?

Answer 14

AES (Advanced Encryption Standard) is a symmetric encryption algorithm widely used for its efficiency and security, supporting key lengths of 128, 192, or 256 bits

Question 15

What is the RSA encryption algorithm?

Answer 15

RSA (Rivest-Shamir-Adleman) is a widely-used asymmetric encryption algorithm for secure data transmission and digital signatures, based on the difficulty of factoring large prime numbers​​.

Question 17

What is HTTP security

Answer 17

HTTP security refers to measures taken to protect communication between clients and servers from unauthorized access, data breaches, and other security threats.