"Hi, Amigo!"

"Hello, Bilaabo! What are we doing today?"

"Today I'm going to tell you how to install a Tomcat web server."

Install and configure Tomcat - 1

"What's a web server? What's a regular server?"

"There is a way for programs to interact called a client-server relationship. The server serves client requests. Clients send their requests to the server, and the server fulfills them and returns the result."

"Imagine a salesperson serving customers in a store. In this case, the salesperson is actually the server, the store's customers are the clients, and the product sold by the salesperson is the result of processing the request (the result of the server's work)."

"In other words, a server is the one who serves a customer's requests/orders/needs, right?"


"Okay, so what's a web server?"

"A web server is a program that serves page requests from users' browsers."

"When you enter a specific URL into a browser, the request goes to the server, the server processes the request, generates a web page, and sends it back to the browser."

Install and configure Tomcat - 2

"The web server is the server. The browser is the client. The URL is the request. The webpage is the result of processing the request."

"Ah. The situation is slowly becoming clearer. In other words, a web server is a program(?) that generates pages for browsers. Right?"


"Let's take an ordinary URL:"

Parsing URLs
Description of parts of a URL
codegym.cc is the domain name the unique name (address) of a computer on the Internet
http is the protocol for client-server communication
alpha/api/contacts is the web server request or request for a webpage on the server
userid=13 &filter=none & page=3  is the web server request or request for a webpage on the server

"Check it out. We get a computer and connect it to the Internet."

"Then we buy a domain name for it."

"Then we run a web server on it."

"Now you can send requests to this web server from any browser by entering a URL with its domain name."

"I think I understand."

"I'll share an analogy to make everything a little clearer."

Parsing URL conversations
English://Jason/pass me folder?number=13
Description of parts of the URL
Jason is the unique name of a computer on the Internet
English is the protocol for client-server communication
pass me folder is the web server request, or the request for a webpage on the server
number=13 is a string with the request parameters

"Ah. That really is clearer. Thanks."

"That's not all. Sometimes several web servers run on a single computer. To distinguish them, they are assigned numbers."

"Think of a domain as a building. If one family lives in the building, then you would write something like «5 Third Anti-Martian Uprising St.» when sending them a letter."

"Now imagine that several families live in the building."

"Like an apartment building?"

"Exactly! It's very similar. Thanks for the analogy."

"Inside the building, there are many apartments. Some apartments are unoccupied. Some are occupied by web servers. And when you send a request to a web server, you must also specify the apartment number. In a URL, this number is called a port."

"For example:"


"In reality, all servers are apartment buildings. And each has 65,000 apartments (ports)."

"Why 65,000?"

"Two bytes are used to indicate a port number. 65536 is the largest integer value that is two bytes long."

"Each protocol (http, https, ftp, ...) has its own default port."

"If the apartment number (port) is not specified, the protocol's default port is used."

"If the protocol is http, then the port is 80. If the protocol is https, then the port is 443, etc."

"In other words, the following entries are equivalent:"

URL What it really means
http://www.mail.google.com http://www.mail.google.com:80
http://codegym.cc http://codegym.cc:80
http://codegym.cc/alpha http://codegym.cc:80/alpha
https://codegym.cc/api?x https://codegym.cc:443/api?x

"What if the port is 444, but the protocol is https?"

"I already told you. If the port isn't specified, then it is determined based on the protocol. If it is specified, then the specified port is used."

"I see."

"You know how humans sometimes use pronouns instead of names: I, you, he, …?"

"Yeah, but people are inherently strange. I try not to pay attention to that."

"Well, computers also have a domain name that means 'I'. It's 'localhost'."

"If you enter localhost in your browser, the browser will access your computer."

"And if you have a web server installed, then it will send a webpage to the browser."

"Cool! I want to start a web server and open pages in the browser."

"Tell me how to do that, Bilaabo. Please!!! You're my friend, right?"

"Bilaabo would do anything for a friend."

"Listen up."

Step 1
Install the Java Development Kit (JDK)
The JDK is installed

"Bilaabo, I'm a Level 30 programmer. I installed the JDK a long time ago!"

"Great, then let's carry on."

Step 2
Download Tomcat 9
Hint 1:
Use Google
Hint 2:
Official Apache Tomcat webpage
Hint 3 (direct link for Windows users):
Download Apache Tomcat

"Got it."


Step 3
Install Tomcat 9
Use the default installation settings.
Don't change anything.
Screen 3
Install and configure Tomcat - 3
Screen 4
Install and configure Tomcat - 4

"Here you can set the web server's name and port. The default is port 8080.
Don't change anything. Leave everything as it is."

Screen 5
Install and configure Tomcat - 5

Specify the folder where the JDK is installed

Screen 6
Install and configure Tomcat - 6
Screen 7
Install and configure Tomcat - 7

"Yep. I just clicked Next and that's it."

"Great. Now you have a Tomcat 9 web server installed and running, listening for requests on port 8080. This is the standard port for software development."

"Okay, so I have Tomcat, but how can I write a program for it?"

"I want it to generate something interesting—some sort of cool webpage."

"OK, I'll tell you how to do that after a short break."