Difference between Servlet and JSF

Last Updated : 09 Jul, 2024

Servlet

Servlets are Java programs that run on a server and handle client requests to generate dynamic web content. They operate at a lower level within the Java EE framework, providing a powerful and flexible mechanism for building web applications. Servlets are mainly used to extend the applications hosted by web services.

Pseudo Code/Syntax

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.IOException;
import java.io.PrintWriter;

public class HelloWorldServlet extends HttpServlet {
    
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setContentType("text/html");
        PrintWriter out = response.getWriter();
        out.println("<html>");
        out.println("<head><title>Hello World GeeksforGeeks</title></head>");
        out.println("<body>");
        out.println("<h1>Hello, Geeks!</h1>");
        out.println("</body>");
        out.println("</html>");
    }
}

JSF

JavaServer Faces (JSF) is a Java framework for building component-based user interfaces for web applications. It abstracts many of the complexities involved in developing web UI by providing a robust set of reusable UI components and managing the state of these components.

Pseudo Code/Syntax

//JSF Facelets Page (XHTML)

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml"
      xmlns:h="http://xmlns.jcp.org/jsf/html">
<head>
    <title>Hello GFG</title>
</head>
<body>
    <h:form>
        <h:outputText value="#{helloWorldBean.message}" />
    </h:form>
</body>
</html>

Servlet	JSF
Low-level API for handling HTTP requests and responses.	Higher-level framework for building component-based user interfaces.
Typically used for backend logic and processing.	Focuses on frontend UI development, integrating well with backend services.
Directly writes HTML and handles HTTP responses via PrintWriter or similar.	Uses Facelets (XHTML) for defining UI components and templates.
Integrates with other frameworks and libraries like JSP, JSTL, and custom tag libraries.	Integrates seamlessly with other Java EE technologies and provides a rich set of built-in components.
Requires explicit handling of page navigation and state management.	Uses built-in navigation and state management features.
More control over the request and response lifecycle, but with more complexity.	Simplifies UI development with built-in components and event handling.
Error handling and validation need to be implemented manually.	Provides built-in support for validation and error handling with ease.
Deployment typically involves packaging as a WAR file for a servlet container.	Also deployed as a WAR file but includes configuration for JSF-specific features and libraries.
More control over the request and response lifecycle, but with more complexity.	Simplifies UI development with built-in components and event handling.