Java™ Application Development on Linux - Dator

18.3 Perspective405Linux systemWeb serverServlet classHTTP requestHTMLPCWeb browserFigure 18.1 Servlet diagram• doPost(HttpServletRequest request, HttpServletResponseresponse)We hope that you’ve noticed the similarity between doGet(), doPost(),and the previously mentioned service() method. More on that in a minute.18.3PERSPECTIVETo better understand the interaction with servlets, let’s consider the requeststhat come to a Web server. Web servers serve up Web pages. At first (in theearly days of the Web) that just meant simple flat HTML files, along with afew image types. A Web browser would send a request to a Web server in theform of a URL, such as http://www.dom.com/file.html, which would besent to the Web server named www at the dom.com domain. It would look upthe file named file.html in its directory and send it back to the browser.That approach worked fine, and still does today. But this only covers staticWeb pages, ones whose content doesn’t change. Users want to get at lots moreinformation today, not all of which has been embodied in static Web pages.