Re: Bean Database Connection

Ben Dudley Fri, 27 Aug 1999 01:07:21 -0700

Yes it is possible - the example code given in Websphere (below) writes HTML out to the request object from the DataBean.

Hope this helps,

Ben Dudley

===================================================

Sylvian asked:

Hi,

You seems to be doing interesting stuff with JSP, I would like to ask
you one question. Is it me or it is impossible for a bean to have
access to the sessions, the request, the response, etc... objects?

Regards,
Sylvain.

=====================================================

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SERVLET that handles requests:

----------------------------------------------------------------------------------------------------------

import java.io.*;
import java.beans.Beans;

import javax.servlet.*;
import javax.servlet.http.*;

import DataBean;

/******************************************************************
* PopulateBeanServlet - This servlet creates an instance of a Bean
* (DataBean), sets several of its parameters, sets the Bean instance
* as an attribute in the request object, and invokes a JSP file to
* format and display the Bean data.
*******************************************************************/

public class PopulateBeanServlet extends HttpServlet
{

   public void Service(HttpServletRequest req, HttpServletResponse res)
      throws ServletException, IOException
{
      DataBean dataBean;

      // Create an instance of DataBean

      try
     {
         dataBean = (DataBean) Beans.instantiate(this.getClass().getClassLoader(), "DataBean");
      }
      catch (Exception ex)
      {
         throw new ServletException("Can't create BEAN of class DataBean: "
                                      + ex.getMessage());
      }

      String postcode = req.getParameter("postcode");

      // Set some Bean properties (content generation)
      dataBean.setPostcode(postcode);

      // To send the Bean to a JSP file for content formatting and display
      // 1) Set the Bean as an attribute in the current request object
      ((com.sun.server.http.HttpServiceRequest) req).setAttribute("dataBean", dataBean);

      // 2) Use callPage to invoke the JSP file and pass the current request object
      ((com.sun.server.http.HttpServiceResponse) res).callPage("/DisplayData.jsp", req);

   }

} /* end of class PopulateBeanServlet */

----------------------------------------------------------------------------------------------------------------------------------

DataBean - writes to the request object

---------------------------------------------------------------------------------------------------------------------------------

import javax.servlet.http.*;
import java.io.PrintWriter;
import java.io.IOException;

public class DataBean extends HttpServlet {

String Prop1 = "DefaultValueofProp1";

 public void service(HttpServletRequest req, HttpServletResponse res)
throws IOException
 {
PrintWriter writer = res.getWriter();
writer.println(" This is output from DataBean");
 }

 public void setProp1(String Prop1) {
 this.Prop1 = Prop1;
 }
 public String getProp1() {
 return Prop1;
 }
}

------------------------------------------------------------------------------------------------------------------

JSP output

----------------------------------------------------------------------------------------------------------------

DisplayData.jsp sample


<html>
<head>
<title>Bean Data Display</title>
</head>


<bean name="dataBean" type="DataBean" introspect="no" create="no" scope="request">
</bean>
<body>


<% out.println("The value of Bean property 1 is " + dataBeans.getProp1());
%>


The value of Bean property 2 is
<%= dataBean.getProp2() %> 

<-- Using the INSERT tag -->
The value of Bean property 3 is
<insert bean=dataBean property=prop3 default="No property value" >
</insert>

</body>
</html>

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Re: Bean Database Connection

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