One of the original Java web technologies, JSP is still widely used with servlets and JSTL. Here’s how to use Jakarta Server Pages to build dynamic web pages that connect to the Java back end.
Jakarta Server Pages (formerly JavaServer Pages) is a Java standard technology that developers use to write dynamic, data-driven web pages for Java web applications. JSP is built on top of the Java Servlet (aka Jakarta Servlet) specification and is one of the Java web technologies included for ongoing support and upgrades in Jakarta EE.
JSP and servlets typically work together, especially in older Java web applications. From a coding perspective, the most obvious difference between JSP and servlets is that with servlets you write Java code and then embed client-side markup (like HTML) into that code. With JSP, you start with the client-side script or markup, then embed JSP tags to connect your page to the Java back end.
Think of JSP as a way to write markup with superpowers for interacting with the back end. Usually, markup like HTML is sent to the client where it interacts with the back-end server via JavaScript. JSP pre-processes the HTML with special commands to access and use server capabilities, then sends that compiled page to the client.
The benefits of using JSP are manifold. One of the primary advantages is the separation of concerns it facilitates. By separating the presentation layer from the application logic, JSP allows developers to focus on the user interface while backend developers concentrate on the business logic. This separation enhances maintainability and scalability of the web application.
Another significant advantage is the use of the Java Standard Tag Library (JSTL). JSTL provides a set of tags that encapsulate core functionality common to many web applications. These tags can be used for tasks such as iteration, conditional processing, and data formatting, thus reducing the need for scriptlets and making the JSP code more readable and easier to maintain.
JSP pages are compiled into servlets by the server before they are run, which means they benefit from the performance optimizations available to servlets. This compilation process allows JSP to deliver dynamic content quickly and efficiently, making it suitable for high-traffic web applications. Additionally, JSP can be used in conjunction with frameworks like Spring and Struts, further extending its capabilities and integration options.
In summary, Jakarta Server Pages remains a powerful tool for Java web developers. It simplifies the creation of dynamic, interactive web pages and integrates seamlessly with the Java ecosystem. Whether you are maintaining legacy systems or developing new applications, understanding JSP can be a valuable addition to your Java development skills.