JavaEE learning records and javaee records

JavaEE learning records and javaee records
TCP/IP layer-4 model HTTP protocol

Hypertext Transfer Protocol (text, audio, and video) is a distributed, cooperative, Multimedia Information System Service, application-layer protocol.

HTTP Request

Common Methods for request lines, message headers (message lines), and request bodies: GET and POST

HTTP Response

Status line, message header, response body

Differences between static Web and dynamic Web

Static Web means that you cannot continue database operations. Dynamic Web means you can perform database operations. Dynamic Web is interactive (the server automatically responds to different results based on user requests ).

Web Container

Web containers manage and run servlets

CGI defect: each request opens a process. System resources are greatly consumed and high concurrency is not supported.

Dynamic Web TechnologyServletServlet Lifecycle

Under normal circumstances, it will only be initialized and destroyed once. In special cases (for example, the Servlet is not used for a long time), it will be called multiple times.

Basic Servlet Configuration

Container search:Full match> directory match (starting from the longest directory match)> extension match