Servlet and JSP are server-side technologies in Java used to build dynamic web applications. While both handle requests and responses, they differ in purpose and usage.
- When we need to handle business logic, form processing, and request management.
- When we need to build dynamic web pages with UI elements and embed minimal Java logic.
Servlet
A Servlet is a Java class used to handle client requests and generate dynamic responses on the server. It is mainly used for processing business logic and controlling application flow.
- Handles request-response processing and form data.
- Written entirely in Java, making it suitable for backend logic.
Real-world Example: When a user submits a login form, the servlet checks the username and password from the database and decides whether login is successful or not.
JSP
JSP is a server-side technology used to create dynamic web pages by embedding Java code in HTML. It focuses more on presentation and UI development.
- Combines HTML with Java for dynamic content generation.
- Easier to design UI compared to servlets.
Real-world Example: After successful login, a JSP page displays the user dashboard with welcome message and user details.
Servlet Vs JSP
The difference between servlet and JSP are as follows:
| Feature | Servlet | JSP (JavaServer Pages) |
|---|---|---|
| Definition | A Java class used to handle requests and generate responses | A technology used to create dynamic web pages using HTML + Java |
| Type | Pure Java code | HTML with embedded Java code |
| Compilation | Already compiled Java class | First converted into Servlet, then compiled |
| Coding Style | Java-centric (more logic) | HTML-centric (more UI) |
| Ease of Writing | Difficult for UI design | Easy for UI design |
| Use Case | Business logic, request handling | Presentation layer (view) |
| Performance | Slightly faster (direct execution) | Slightly slower (converted to servlet first) |
| Maintenance | Harder (mixing UI in Java code) | Easier (separation of concerns) |
| Built-in Objects | No implicit objects | Provides implicit objects (request, response, session, etc.) |
| Tag Support | No tag libraries | Supports JSTL and custom tags |
| MVC Role | Works as Controller | Works as View |
