Servlet Communicates with JSP Pages

Q

How does a servlet communicate with a JSP page?

✍: FYICENTER.com

A

The following code snippet shows how a servlet instantiates a bean and initializes it with FORM data posted by a browser. The bean is then placed into the request, and the call is then forwarded to the JSP page, Bean1.jsp, by means of a request dispatcher for downstream processing.

public void doPost (HttpServletRequest request, 
   HttpServletResponse response) {
try {
   govi.FormBean f = new govi.FormBean();
   String id = request.getParameter("id");
   f.setName(request.getParameter("name"));
   f.setAddr(request.getParameter("addr"));
   f.setAge(request.getParameter("age"));

   //use the id to compute
   //additional bean properties like info
   //maybe perform a db query, etc.
   // . . .

   f.setPersonalizationInfo(info);
   request.setAttribute("fBean",f);
   getServletConfig().getServletContext()
      .getRequestDispatcher(
      "/jsp/Bean1.jsp").forward(request, response);
} catch (Exception ex) {
   . . .
}
}

The JSP page Bean1.jsp can then process fBean, a fter first extracting it from the default request scope via the useBean action.

<jsp:useBean id="fBean" class="govi.FormBean"
   scope="request"/>
<jsp:getProperty name="fBean" property="name" />
<jsp:getProperty name="fBean" property="addr" />
<jsp:getProperty name="fBean" property="age" />
<jsp:getProperty name="fBean" property="other" />

2007-04-03, 4627👍, 0💬