com.imsl.chart

Class ChartServlet

java.lang.Object

javax.servlet.GenericServlet

javax.servlet.http.HttpServlet

com.imsl.chart.ChartServlet

All Implemented Interfaces:

Serializable, Servlet, ServletConfig

public class ChartServlet
extends HttpServlet

The base class for chart servlets.

This class requires a javax.servlet Images are rendered using ImageIO This class can be used on a headless server. Java runs in a headless mode if the system property java.awt.headless=true. This class turns off caching in the ImageIO class (calls javax.imageio.ImageIO.setUseCache(false)).

See Also:

Chart Programmer's Guide: Servlets, Java Servlets, Serialized Form

Constructor Summary

Constructors

Constructor and Description
ChartServlet()

Method Summary

Methods

Modifier and Type	Method and Description
protected void	doGet(HttpServletRequest request, HttpServletResponse response) Returns the chart as a PNG image.
protected Chart	getChart(HttpServletRequest request) Returns the chart found in the session saved with the key "chart"+id, where id is the value of the "id" parameter in the request.
void	init()

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

Constructor Detail

ChartServlet

public ChartServlet()

Method Detail

doGet

protected void doGet(HttpServletRequest request,
         HttpServletResponse response)
              throws ServletException,
                     IOException

Returns the chart as a PNG image. The HTTP request parameter "id" selects the chart.

Overrides:

doGet in class HttpServlet

Parameters:

request - an HttpServletRequest object that contains the request the client has made of the servlet

response - an HttpServletResponse object that contains the response the servlet sends to the client

Throws:

ServletException

IOException

getChart

protected Chart getChart(HttpServletRequest request)

Returns the chart found in the session saved with the key "chart"+id, where id is the value of the "id" parameter in the request. This method can be overridden to change how charts are communicated to this servlet.

Parameters:

request - an HttpServletRequest object that contains the request the client has made of the servlet

Returns:

the chart to be rendered or null if the chart cannot be found.

See Also:

JspBean

init

public void init()
          throws ServletException

Overrides:

init in class GenericServlet

Throws:

ServletException