What are the benefits and challenges of using servlets in Jakarta EE?

1 Servlet API

The Servlet API is the set of interfaces and classes that define how servlets interact with the web container and other components. The Servlet API is part of the Jakarta EE specification and provides common functionality such as request and response handling, session management, filtering, listeners, and annotations. The Servlet API is designed to be flexible and extensible, allowing you to create custom servlets or use existing ones.

2 Servlet Lifecycle

The servlet lifecycle is the sequence of events that occurs when a servlet is initialized, processed, and destroyed by the web container. The servlet lifecycle consists of four phases: loading, instantiation, initialization, and service. The web container manages the servlet lifecycle and invokes the appropriate methods of the servlet class. The servlet lifecycle is important to understand because it affects how you manage resources, handle concurrency, and optimize performance.

3 Servlet Benefits

One of the main benefits of using servlets in Jakarta EE is that they are fast, efficient, and scalable. Servlets run on the server side, which means they can leverage the power and resources of the web container. Servlets are also stateless, which means they do not store any information between requests, reducing the memory and processing overhead. Servlets are also easy to integrate with other Jakarta EE technologies, such as JavaServer Pages (JSP), JavaServer Faces (JSF), and Enterprise JavaBeans (EJB).

4 Servlet Challenges

However, using servlets in Jakarta EE also comes with some challenges. One of the challenges is that servlets are low-level and require more coding and configuration than higher-level frameworks. Servlets also lack some features that are common in modern web development, such as templating, validation, security, and dependency injection. Moreover, servlets are not very suitable for complex user interfaces, as they rely on HTML and JavaScript for presentation logic.

5 Servlet Alternatives

If you are looking for alternatives to servlets in Jakarta EE, you can choose from several popular options. JSP is a technology that allows you to embed Java code in HTML pages, creating dynamic web content. It is based on servlets and can use the same Servlet API, but simplifies development by separating presentation from business logic. JSF is a component-based framework that provides a rich set of user interface components such as buttons, tables, forms, and charts, and supports validation, conversion, navigation, and event handling. Spring MVC is another framework that follows the Model-View-Controller (MVC) pattern to separate the application logic into three layers: model, view, and controller. It also provides features like dependency injection, security, testing, and data access.

6 Servlet Best Practices

If you choose to use servlets in Jakarta EE, there are several best practices you should follow to ensure quality and performance. Annotations, such as @WebServlet, @WebFilter, and @WebListener, are a great way to add metadata to your servlet classes and methods, simplifying configuration and deployment. Additionally, filters can be used to intercept and modify requests and responses before or after they reach the servlet for tasks like logging, authentication, compression, and caching. Lastly, listeners can be used to listen to events that occur in the web container or the servlet context for tasks such as resource allocation, cleanup, or notification.