How are the JSP requests handled?

On the arrival of a JSP request, the browser first requests a page with a .jsp extension. Then, the Web server reads the request and using the JSP compiler, the Web server converts the JSP page into a servlet class. Notice that the JSP file is compiled only on the first request of the page, or if the JSP file has changed.The generated servlet class is invoked, in order to handle the browser’s request. Once the execution of the request is over, the servlet sends a response back to the client.

With this example we are going to demonstrate how to get Request Parameters in a JSP page. JavaServer Pages (JSP) is a server-side programming technology that enables the creation of dynamic, platform-independent method for building Web-based applications. JSP have access to the entire family of Java APIs, including the JDBC API to access enterprise databases. In short, to get Request Parameters in a JSP page you should:

• Create a jsp page that begins with the <%code fragment%> scriptlet. It can contain any number of JAVA language statements, variable or method declarations, or expressions that are valid in the page scripting language.
• Use the getParameter(String name) API method of javax.servlet.http.HttpServletRequest object to get the value of a request parameter as a String.

Let’s take a look at the code snippet that follows:

GetRequestParameter.jsp

URL:

http://localhost:8080/jcgsnippets/GetRequestParameter.jsp?myparam=myvalue

Output:

Parameter myparam: myvalue

This was an example of how to get Request Parameters in a JSP page.