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

public class CewolfRenderer
extends javax.servlet.http.HttpServlet

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.

Author:

Guido Laures

See Also:

ChartImgTag, LegendTag, Serialized Form

Field Summary

static java.lang.String	INIT_CONFIG
static java.lang.String	WEB_ROOT_DIR

Constructor Summary

CewolfRenderer()

Method Summary

protected void	doGet(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Processes HTTP GET request.
void	init(javax.servlet.ServletConfig servletCfg)
void	printParameters(javax.servlet.http.HttpServletRequest request)

Methods inherited from class javax.servlet.http.HttpServlet

doDelete, doHead, doOptions, doPost, doPut, doTrace, getLastModified, service, 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

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

Field Detail

INIT_CONFIG

public static final java.lang.String INIT_CONFIG

See Also:

Constant Field Values

WEB_ROOT_DIR

public static final java.lang.String WEB_ROOT_DIR

See Also:

Constant Field Values

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

Overrides:

init in class javax.servlet.GenericServlet

Throws:

javax.servlet.ServletException

printParameters

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

doGet

protected void doGet(javax.servlet.http.HttpServletRequest request,
                     javax.servlet.http.HttpServletResponse response)
              throws javax.servlet.ServletException,
                     java.io.IOException

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

Overrides:

doGet in class javax.servlet.http.HttpServlet

Parameters:

request - servlet request

Throws:

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

java.io.IOException