org.deegree.enterprise.servlet
Class ChartServlet

java.lang.Object
  javax.servlet.GenericServlet
      javax.servlet.http.HttpServlet
          org.deegree.enterprise.servlet.ChartServlet

All Implemented Interfaces:

Serializable, javax.servlet.Servlet, javax.servlet.ServletConfig

public class ChartServlet
extends javax.servlet.http.HttpServlet

A Servlet that gets an http GET request, with the de.latlon.charts parameters and it generates and returns a BufferedImage based on these parameters. The request should look as follows: http://www.someserver.com/servletname? chart=ChartType& ( Mandatory ) title=string& legend=boolean& ( default = true ) width=int& ( Mandatory ) height=int& ( Mandatory ) xAxis=string& yAxis=string& tooltips=boolean& ( default = false ) lblType Determines in PieChart what the legend and the tool tip to be. You can either show the data key, value or both. Possible values for this parameter are: Key, Value and KeyValue ( default = Key ) orientation=direction& ( default = vertical ) format=image_format& ( Mandatory ) value=value ( Mandatory ) The keys are the following I) Chart Type: Available chart Types are: 1- Pie 2- Pie3D 3- Bar 4- Bar3D 5- Line 6- Line3D 7- XYBar 8- XYLine II) title: Title of the generated image II) legend: true/false to show/hide the legend of the categories/rows III) width: Width of the generated image IV) height: Height of the generated image V) xAxis Title of the X Axis Title of xAxis VI) yAxis Title of the Y Axis VII) tooltips Show/hide tool tips VIII)orientation vertical/horizontal. the orientation of the chart IX) format format of the output image, ex: image/png and image/jpeg X) type There is actually no parameter called type. It only indicates the more parameters that carry the actual values for the chart. They can have different three different formats. but only one format type shall be used per request. The values can be given as normal key value pairs as follows: Format 1: &CDU=34&SPD=36&Gruene=11 - In this format the key has only one value - This type can only be used together with the chart type: Pie, Pie3D, Bar, Line and Line3D Format 2: &CDU=23,25,21,26&SPD=42,23,33,36 - In this format multiple values per keys can be given - Either comma or white spaces can be used as separators(white spaces are of course encoded in case of a Http Get request) - This type can only be used together with the chart type: Bar, Line and ine3D Format 3: &CDU=1970,23;1974,44;1978,43&SPD=1970,23;1974,44;1978,43 - In this format the key has multiple value, in which each value is a tuple that contains in turn two tokens representing x and y of a cartesian point. This format is used to create cartesian de.latlon.charts - comma and white spacescan be used as separators between tokens, i.e. between x and y, while semi colon shall be used as a separator between tupels. - This type can only be used together with XYLine (and later with XYBar)

Version:

$Revision: 29949 $, $Date: 2011-03-09 13:08:56 +0100 (Wed, 09 Mar 2011) $

Author:

Moataz Elmasry, last edited by: $Author: apoth $

See Also:

Serialized Form

Constructor Summary

ChartServlet()

Method Summary

protected BufferedImage	buildChart(String chart, String title, String legend, String width, String height, String xAxis, String yAxis, String tooltips, String orientation, String lblType, String imagetype, Map<String,String> params, ChartConfig chartConfigs) Takes in all the needed parameters and a queued map containing the values of the chart and returns a BufferedImage with the chart
protected void	doGet(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)
protected void	goToErrorPage(javax.servlet.http.HttpServletResponse response) Creates a buffered image that contains an error label.
void	init()
protected QueuedMap<String,String>	initAndValidateParams(javax.servlet.http.HttpServletRequest request) Init and validate params does what its name say.
protected void	performAction(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)

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

init

public void init()
          throws javax.servlet.ServletException

Overrides:

init in class javax.servlet.GenericServlet

Throws:

javax.servlet.ServletException

doGet

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

Overrides:

doGet in class javax.servlet.http.HttpServlet

Throws:

javax.servlet.ServletException

IOException

performAction

protected void performAction(javax.servlet.http.HttpServletRequest request,
                             javax.servlet.http.HttpServletResponse response)

Parameters:

request -

response -

initAndValidateParams

protected QueuedMap<String,String> initAndValidateParams(javax.servlet.http.HttpServletRequest request)
                                                  throws IncorrectFormatException

Init and validate params does what its name say. It extracts the mandatory parameters from the HttpServletRequest class and checks their validity. Then it fills a queued map with all parameters, that are not defined, because these are the candidates to be the parameters for the chart

Parameters:

request -

Returns:

instance of the queued map with

Throws:

IncorrectFormatException

goToErrorPage

protected void goToErrorPage(javax.servlet.http.HttpServletResponse response)

Creates a buffered image that contains an error label. It is used to display an error instead of a chart in case an error happened

Parameters:

response -

buildChart

protected BufferedImage buildChart(String chart,
                                   String title,
                                   String legend,
                                   String width,
                                   String height,
                                   String xAxis,
                                   String yAxis,
                                   String tooltips,
                                   String orientation,
                                   String lblType,
                                   String imagetype,
                                   Map<String,String> params,
                                   ChartConfig chartConfigs)
                            throws IncorrectFormatException

Takes in all the needed parameters and a queued map containing the values of the chart and returns a BufferedImage with the chart

Parameters:

chart -

title -

legend -

width -

height -

xAxis -

yAxis -

tooltips -

orientation -

lblType -

imagetype -

params -

chartConfigs - to configure the output chart, or null to use the default ChartConfig

Returns:

BufferedImage containing the chart

Throws:

IncorrectFormatException