de.laures.cewolf
Class CewolfRenderer

java.lang.Object
  javax.servlet.GenericServlet
      javax.servlet.http.HttpServlet
          de.laures.cewolf.CewolfRenderer

All Implemented Interfaces:

java.io.Serializable, javax.servlet.Servlet, javax.servlet.ServletConfig, WebConstants

public class CewolfRenderer

extends javax.servlet.http.HttpServlet

implements WebConstants

The rendering servlet of Cewolf. It is resposible for writing an entire chart img into the response stream of the client. Everything needed for this is prepared already by the ChartImgTag resp. LegendTag. The ID of a chart image is passed to this servlet as a request parameter. After that the image object is retrieved from the server side session based image cache. This servlet must be configured in web.xml of the web application in order to use Cewolf services. The servlet's URL relative to the web apps root is used as the renderer attribute of the ChartImgTag resp. LegendTag in the JSP page.

Since:

0.1

Author:

Guido Laures

See Also:

ChartImgTag, LegendTag, Serialized Form

Field Summary

Fields inherited from interface de.laures.cewolf.WebConstants

AMPERSAND, HEIGHT_PARAM, IMG_PARAM, MIME_PNG, MIME_SVG, SESSIONID_KEY, WIDTH_PARAM

Constructor Summary

CewolfRenderer()

Method Summary

void	init(javax.servlet.ServletConfig servletCfg)
void	printParameters(javax.servlet.http.HttpServletRequest request) Processes HTTP GET request.

Methods inherited from class javax.servlet.http.HttpServlet

service

Methods inherited from class javax.servlet.GenericServlet

destroy, getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletInfo, getServletName, init, log, log

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CewolfRenderer

public CewolfRenderer()

Method Detail

init

public void init(javax.servlet.ServletConfig servletCfg)
          throws javax.servlet.ServletException

Specified by:

init in interface javax.servlet.Servlet

Throws:

javax.servlet.ServletException

printParameters

public void printParameters(javax.servlet.http.HttpServletRequest request)

Processes HTTP GET request. Renders the chart or the lengend into the client's response stream.

Parameters:

request - servlet request

Throws:

javax.servlet.ServletException - when the production of data could not be handled by the configured DatasetProcuder