Java Enterprise Best Practices

Working Effectively with Servlets

We start with a look at servlet frameworks. Frameworks (e.g., Apache Struts) are becoming increasingly popular because they increase programmer efficiency by providing a skeleton on which applications can be built. In the first section, we examine what servlet frameworks offer, and I give a quick overview of the most popular frameworks. After that, we jump from the high level to the low level with a discussion on how using pre-encoded characters can optimize your servlet’s performance. Next, we tackle the thorny issue of loading configuration files and provide some code to make the task easier, and after that I give some tips on when you should (or should not) use the HttpSession and SingleThreadModel features. As we near the end of the chapter, I explain how to reliably control caching to improve the user’s experience. Then I address the frequently asked question: “How do I download a file to the client so that the client sees a `Save As’ pop up?” As you’ll see, the answer lies in setting the right HTTP headers.