JSP vs Servlet: Key Differences & When to Use Each
JSP is a templating engine that turns HTML sprinkled with Java tags into servlets, letting designers build dynamic pages without writing raw Java. Servlet is a pure Java class that handles HTTP requests and responses directly, giving developers tight control over every byte sent to the browser.
People mix them up because both end up in the browser and both contain Java. Picture a graphic designer updating an online store layout: she tweaks a JSP file like a normal HTML page and never sees a Servlet. Meanwhile, the backend dev who wrote the Servlet worries about headers and threads yet never touches the markup. Same web app, two totally different worlds.
Key Differences
JSP feels like HTML with superpowers—tags, EL, and JSTL—compiled into a Servlet at runtime. Servlet is pure Java: extend HttpServlet, override doGet/doPost, and write response.getWriter(). JSP pushes presentation logic into markup; Servlet pushes presentation into Java code.
Which One Should You Choose?
Need fast, designer-friendly pages? JSP wins. Need fine-grained control, REST endpoints, or non-HTML output (PDF, JSON)? Servlet or its modern frameworks rule. Many teams pair them: JSP for views, Servlet (or Spring MVC controller) for logic.
Examples and Daily Life
Think of JSP as the editable menu board at a café—staff swap text without calling IT. The Servlet is the barista who actually grinds beans and pours shots. Together they serve fresh coffee (your webpage) without confusing roles.
Can a JSP exist without a Servlet?
No. The container silently translates JSP into a Servlet class, so every JSP is ultimately a Servlet under the hood.
Is JSP outdated in 2024?
Not dead, but largely superseded by Thymeleaf, React, or Spring Boot templates. Legacy apps still rely on it.
When would I pick Servlet over Spring MVC?
For lightweight micro-services or when you want zero framework overhead—just raw speed and control.