Web application, architecture, logic, Java, Servlet, EL, JSP, HTML, SQL, JDBC and Herculean porridge in my head. Was it like this for everyone at first?

Question

MySQL

I ask the community to help me in assembling the puzzle of all these technologies, concepts, developments dazzling on the net and put in my head an understanding of the operation of a simple web application (client - server - database).

I use Tomcat 8, IntellijIDEA Ultimate,

I think it will be useful for beginners. I will use ordinary words and terms, AND I CALL ALL COMMENTATORS TO THIS!!! TO STATE IN TECHNICAL SLANG, THIS IS A MATTER OF EXPERIENCE, A BEGINNER WILL NOT BE USEFUL FROM THIS AT THE FIRST!!!

Briefly, the author's vision for all this:

1. A young girl enters the Bentley website and fills out the "Get a red Bentley Bentayga as a gift" form, clicks "Get";

2. HTML form code in JSP(index.jsp) sends a request to the server (ServletBentley);

3. in the ServletBentley class (Class Select) with the DAO code sends a request "red Bentley Bentayga" to the database;

4. The girl is lucky!) There is a red Bentley Bentayga in the database;

5. what Class Select tells ServletBentley;

6. ServletBentley server delivers this news to JSP(index.jsp);

7. The girl is happy!!!

This is such a mess in my head!) How do you think this logic should be implemented?

Answer 1

At first, I generally had and sometimes still have spaghetti code (when HTML, CSS, java, JavaScript and all in one file), all with a page reload and no division into backend and frontend.
there is a small example here and JSP and servlet with DAO, but in principle it performs almost everything you need , but keep in mind
that there is an outdated servlet description specification, you can no longer do this in web.xml.