Java Servlet technology, referred to as Servlet technology, is the underlying technology for developing web applications in Java. A servlet is a java program, and a servlet application has one or more servlet programs. The jsp page will be converted and compiled into a servlet program. A servlet application cannot run independently and must run in a servlet container. The servlet container passes the user's request to the servlet application and returns the result to the user. Since most servlet applications contain multiple jsp pages, it is more accurate to say "servlet/jsp application".
Architecture of Servlet/jsp application:
A web user accesses a servlet application through a web browser, which is also called a web client.
The communication between the web server and the web client is through the Http protocol, so the web server is also called the http server.
http request, response
An http request consists of three parts:
method-url-protocol/version
request header information
request body
The http response contains three parts:
protocol-status-code-description
response header information
response body
(About http content, I will follow up a module to learn http request and its related in detail)