GenericServlet vs HttpServlet: Difference and Comparison

Key Takeaways

1. GenericServlet provides basic web servlet methods, while HttpServlet adds HTTP-specific methods.
2. GenericServlet must override key methods while HttpServlet has default implementations.
3. HttpServlet is commonly subclassed for specific HTTP services while GenericServlet is rarely used directly.

What is GenericServlet?

GenericServlet is an abstract class in the Java Servlet API that provides a foundation for creating servlets. Servlets are Java classes that handle incoming requests and generate responses to those requests, for web applications.

GenericServlet is designed to be a base class that simplifies the creation of servlets by providing default implementations for some of the methods defined in the Servlet interface. This makes it easier for developers to create new servlets by extending GenericServlet and focusing on the specific logic required for their applications.

GenericServlet serves as a convenient base class for creating servlets that aren’t necessarily focused on handling HTTP requests, making it a more generic choice for handling different types of communication protocols within the Java Servlet framework.

What is HttpServlet?

HttpServlet is a class in the Java Servlet API that specifically extends GenericServlet and is designed for handling HTTP requests and generating HTTP responses. It’s part of the Java EE (Enterprise Edition) platform and is used for developing web applications.

HttpServlet is widely used in web application development to handle dynamic content, interact with databases, and perform various operations based on the HTTP requests coming from clients (web browsers). It provides a structured way to implement the server-side logic required for web applications.

Difference Between GenericServelt and HttpServlet

1. It is a more generic class and can be used to handle various communication protocols beyond just HTTP. It is specifically designed to handle HTTP requests and responses. It extends GenericServlet and provides additional methods and features tailored to the HTTP protocol.
2. It uses the ServletRequest and ServletResponse objects to handle incoming requests and generate responses. These objects are protocol-agnostic. It uses the specialized HttpServletRequest and HttpServletResponse objects, which provide methods specifically designed for handling HTTP-related details such as headers, methods, query parameters, and cookies.
3. The service() method signature includes ServletRequest and ServletResponse parameters, allowing for handling requests from various protocols. The service() method signature is overridden to take HttpServletRequest and HttpServletResponse parameters, indicating its specialization in handling HTTP requests.
4. It’s suitable when you want to create a servlet that deals with protocols other than HTTP, such as custom communication protocols or non-web protocols. It’s the go-to choice for building web applications that handle HTTP-based client requests. It’s used extensively in modern web development to create dynamic content, handle forms, interact with databases, etc.
5. It doesn’t provide methods for directly handling HTTP-specific operations like getting request parameters or sending redirect responses. It offers convenience methods like doGet(), doPost(), doPut(), doDelete(), etc., which are invoked based on the HTTP method of the request. These methods make it easier to handle specific HTTP actions in a well-structured manner.

Comparison Between GenericServelt and HttpServlet

Parameters of Comparison	GenericServelt	HttpServelt
Initialization	init(ServletConfig config) method used for initialization.	Same as GenericServlet, uses the init(ServletConfig config) method.
Context Information	Access to servlet context using the getServletContext() method.	Access to servlet context using getServletContext() method.
Content Type	Protocol-independent, not inherently tied to any content type.	Often used for generating HTML, JSON, XML, and other HTTP-specific content types.
Redirection	Can perform redirects but without built-in HTTP redirection methods.	Provides built-in methods like sendRedirect(String location) for HTTP redirection.
MIME Types	Not directly related to MIME type handling.	Provides methods to set MIME types and content headers in HTTP responses.

References

1. https://link.springer.com/chapter/10.1007/978-1-4302-0059-8_13
2. https://books.google.com/books?hl=en&lr=&id=dsU4Lk-Gwk0C&oi=fnd&pg=PR5&dq=difference+between+genericservlet+and+httpservlet&ots=pnJ7J7TsIU&sig=12nsnGqIuRrSef4jPw40S-Ku3gM

Last Updated : 01 September, 2023