How does a Servlet Communicate with a JSP Page

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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, after first extracting it from the default requestscope via the useBean action.

  • <jsp:useBean id=”fBean”class=”govi.FormBean” scope=”request”/>
  • <jsp:getPropertyname=”fBean” property=”name”/>
  • <jsp:getProperty name=”fBean” property=”addr”/>
  • <jsp:getProperty name=”fBean” property=”age”/>
  • <jsp:getProperty name=”fBean” property=”personalizationInfo”/>