Description: A Servlet is a program written in Java that runs on a server and handles client requests, typically through a web browser. Servlets are fundamental components in the architecture of Java-based web applications, as they enable dynamic interaction between the server and the client. They run in a servlet container, which is responsible for managing their lifecycle, from creation to destruction. Servlets can process form data, generate dynamic content, and manage user sessions, making them a versatile tool for web development. Additionally, they can interact with databases and other server resources, allowing them to provide advanced functionalities in web applications. The ability of Servlets to handle multiple requests simultaneously makes them ideal for high-performance applications. In summary, Servlets are an essential part of the Java ecosystem for web application development, providing a robust and scalable way to manage server-side logic.
History: Servlets were introduced by Sun Microsystems in 1997 as part of the Java Servlet API specification. Their development was driven by the need to create more dynamic and efficient web applications compared to earlier technologies like CGI (Common Gateway Interface). Over time, the specification has evolved, and several versions have been released that have improved their functionality and performance, including support for new features such as session management and integration with technologies like JSP (JavaServer Pages).
Uses: Servlets are primarily used in web application development to handle HTTP requests, process form data, generate dynamic content, and manage user sessions. They are widely used in enterprise applications, content management systems, and e-commerce platforms, where constant interaction between the client and server is required.
Examples: A practical example of a Servlet is a login form in a web application. When a user submits their credentials, the Servlet processes the request, verifies the information in a database, and redirects the user to the homepage if the credentials are correct. Another example is a Servlet that generates a PDF report from data stored in a database, allowing users to download the report directly from their browser.
