This example is very similar to what you can find in Deploying a Java Component Over the Web, but this example also uses the DAO. The middle tier code in Hosting the DAO with a Servlet is repeated here:

HttpSession session = request.getSession();

WebFigure userPlot = 
      (WebFigure)session.getAttribute("UserPlot");

// if this is the first time doGet has been called for 
//  this session,
//  create the plot and WebFigure object
if (userPlot== null) 
{
		userPlot = examples.getWebFigureFromMWJavaObjectRef();
		// store the figure in the session context
		session.setAttribute("UserPlot", userPlot);

		// bind the figure's lifetime to the session
		session.setAttribute(
				"UserPlotBinder",
				new MWHttpSessionBinder(userPlot));                       
}    

To use the WebFigure object directly from a JSP page, reference the webfigures tag library. This creates a WebFigure object with your object's parameters. The UserPlot is the name of the Web object that you placed in the cache by the middle tier.

Note   Host the middle tier and the JSP on the same server.

<%@ taglib prefix="wf" uri="/WEB-INF/webfigures.tld" %>

< wf:web-figure
		name="UserPlot" 
		scope="session" 
		root="WebFigures"
		width="100%" 
		height="100%"/>

When using this approach, the only other code needed on the servlet is a redirect back to the JSP that the above code resides on. In this example, this code is contained in response.jsp. The servlet code would look like this:

RequestDispatcher dispatcher =
request.getRequestDispatcher("/response.jsp");
dispatcher.forward(request, response);

This option is convenient since all of the "heavy lifting" is done on the server and only a string is sent to the front end. In this example, notice how the servlet is merely referenced and dumps the contents into a Web page frame.

Tip   This technique can be used regardless of the transfer protocol or location of the front end or back end. Since a simple string is being sent, you can code the front-end in a number of ways, adapting nicely to a SOAP transfer, for example.

<iframe 
		src ="http://localhost:8080/Examples/ExamplesServlet?
                          function=webFigureEmbedded"
		width="590" 
		height="480">
</iframe>

To generate this string, run code similar to this on the servlet:

// The argument to the WebFigureHtmlGenerator 
// constructor is the URL where the 
// WebFigures servlet is mapped (relative to the Web a
// pplication and Servlet context) 
WebFigureHtmlGenerator wfHtmlGenerator = 
    new WebFigureHtmlGenerator("WebFigures", 
                          getServletContext()); 
String embeddedString; 

try 
{ 
//This generates a string that can be sent to the 
// response that represents the WebFigure. 
embeddedString = 
wfHtmlGenerator.getFigureEmbedString( 
                         userPlot, 
                         "UserPlot", 
                         "session", 
                         null, 
                         null, 
                         null)); 
} 
catch(MWException mwe) 
{ 
throw new Exception(); 
} 

response.getOutputStream().println(embeddedString);