| <?xml version="1.0" encoding="utf-8"?> | |
| <!--Arbortext, Inc., 1988-2005, v.4002--> | |
| <!DOCTYPE concept PUBLIC "-//OASIS//DTD DITA Concept//EN" | |
| "concept.dtd"> | |
| <concept id="cwservbn" xml:lang="en-us"> | |
| <title>Servlets</title> | |
| <prolog><metadata> | |
| <keywords><indexterm>servlets<indexterm>overview</indexterm></indexterm><indexterm>dynamic | |
| content<indexterm>servlets</indexterm></indexterm></keywords> | |
| </metadata></prolog> | |
| <conbody> | |
| <p>Servlets are server-side <tm tmclass="special" tmowner="Sun Microsystems, Inc." | |
| tmtype="tm" trademark="Java">Java</tm> programs that use the <cite>Sun Microsystems <tm | |
| tmclass="special" tmowner="Sun Microsystems, Inc." tmtype="tm" trademark="Java">Java</tm> Servlet | |
| API</cite> and its associated classes and methods, as defined in the <cite>Sun | |
| Microsystems <tm tmclass="special" tmowner="Sun Microsystems, Inc." tmtype="tm" | |
| trademark="Java">Java</tm> Servlet 2.3 Specification</cite>. These <tm tmclass="special" | |
| tmowner="Sun Microsystems, Inc." tmtype="tm" trademark="Java">Java</tm> programs | |
| extend the functionality of a Web server by generating dynamic content and | |
| responding to Web client requests. When a browser sends a request to the server, | |
| the server can send the request information to a servlet, so that the servlet | |
| can construct the response that is sent back to the browser.</p> | |
| <p>Just as applets run on a Web browser and extend the browser's capabilities, | |
| servlets run on a Java-enabled Web server and extend the server's capabilities. | |
| Because of their flexibility and scalability, servlets are commonly used to | |
| enable businesses to connect databases to the Web.</p> | |
| <p>Although a servlet can be a completely self-contained program, you can | |
| split application development into two portions: <ul> | |
| <li>The business logic (content generation), which governs the relationship | |
| between input, processing, and output</li> | |
| <li>The presentation logic (content presentation, or graphic design rules), | |
| which determines how information is presented to the user</li> | |
| </ul>Using this paradigm, you may choose to have business logic handled by <tm | |
| tmclass="special" tmowner="Sun Microsystems, Inc." tmtype="tm" trademark="Java">Java</tm> beans, | |
| the presentation logic handled by JavaServer Pages (JSP) or HTML files, and | |
| the HTTP protocol handled by a servlet. <note>JSP files can be used to manage | |
| both the presentation and business logic for a Web application. JSP files | |
| use structured markup for presentation, and supply servlet model behavior | |
| at run time.</note></p> | |
| <p>You can develop, debug, and deploy servlets, set breakpoints within servlet | |
| objects, and step through code to make changes that are dynamically folded | |
| into the running servlet on a running server, without having to restart each | |
| time.</p> | |
| <p>For more information about servlets, refer to the <cite>Sun Microsystems <tm | |
| tmclass="special" tmowner="Sun Microsystems, Inc." tmtype="tm" trademark="Java">Java</tm> Servlet | |
| 2.3 Specification</cite> at <codeph>java.sun.com/products/servlet/download.html</codeph>.</p> | |
| </conbody> | |
| </concept> |