[jCharts-users] dynamic sql statements & jCharts??

[Sean Y. <sy...@dy...>]

Hi,
=20
I have recently began to work with jCharts.  I was able to go through =
all of the tutorials and examples with no problems, generating charts =
with static data.  I am now trying to build a test to generate charts =
based on data passed in from the user via web app and dynamic sql =
statements. =20
=20
This is what I have so far:
=20
public class JChartsApp
{
.
.
.   =20
    public static String renderGMCharts(HttpServletRequest request, =
HttpServletResponse response)=20
    {
        String chartName =3D request.getParameter("chartName");
        String reportName =3D "";
=20
        try
        {
  =20
             if(chartName.equals("chart"))
             {
                 reportName =3D "jChartsReport.jasper";
             }
           =20
            ServletContext application =3D ((ServletContext) =
request.getAttribute("servletContext"));
            File reportFile =3D new =
File(application.getRealPath("/proto/mocuser/reports/" + reportName));
=20
            Map parameters =3D new HashMap();
    =20
            byte[] bytes;
 =20
            bytes =3D
                JasperManager.runReportToPdf(
                reportFile.getPath(),
                parameters,
                new JREmptyDataSource()
                );
   =20
            response.setContentType("application/pdf");
            response.setContentLength(bytes.length);
           =20
            ServletOutputStream ouputStream =3D =
response.getOutputStream();
            ouputStream.write(bytes, 0, bytes.length);
            ouputStream.flush();
            ouputStream.close();  =20
      }
      catch (JRException e)
      {
           e.printStackTrace();
           System.exit(1);
      }
      catch (Exception e)
      {
           e.printStackTrace();
           System.exit(1);
      }
      return "validCharts";
}
       =20
=20
jChartsReport.xml (jChartsReport.jasper) contains a reference to this =
class to generate the chart:
=20
=20
public class JChartsScriptlet extends JRDefaultScriptlet=20
{
    public void afterReportInit() throws JRScriptletException=20
    {
=20
        try=20
        {
=20
            AreaChartProperties areaChartProperties =3D new =
AreaChartProperties();
=20
            double[][] data =3D {{10, 15, 30, 53}, {6, 30, 10, 21}, {20, =
25, 20, 8} };
            Paint[] paints =3D {new Color( 0, 255, 0, 100 ), new Color( =
255, 0, 0, 100 ), new Color( 0, 0, 255, 100 )};
            String[] legendLabels =3D {"Games", "Events", "Players" };
            AxisChartDataSet axisChartDataSet =3D new AxisChartDataSet( =
data, legendLabels, paints, ChartType.AREA, areaChartProperties );
=20
            String[] axisLabels =3D {"January", "March", "May", "June"};
            DataSeries dataSeries =3D new DataSeries( axisLabels, =
"Months", "People", "Popular Events" );
            dataSeries.addIAxisPlotDataSet( axisChartDataSet );=20
=20
            ChartProperties chartProperties =3D new ChartProperties();
            AxisProperties axisProperties =3D new AxisProperties();
            LegendProperties legendProperties =3D new =
LegendProperties();
=20
            AxisChart axisChart =3D new AxisChart( dataSeries, =
chartProperties, axisProperties, legendProperties, 500, 350 );
=20
            BufferedImage bufferedImage =3D new BufferedImage( 500, 350, =
BufferedImage.TYPE_INT_RGB );
=20
            axisChart.setGraphics2D( bufferedImage.createGraphics() );
            axisChart.render();
=20
            super.setVariableValue( "ChartImage", bufferedImage );
      }
      catch( ChartDataException chartDataException )=20
      {
           throw new JRScriptletException( chartDataException );
      }
      catch( PropertyException propertyException )=20
      {
           throw new JRScriptletException( propertyException );
      }
      catch( Exception ex)=20
      {
           throw new JRScriptletException( ex );
      }
 }
=20
=20
The lines in red are to be replaced with data from a database.  But if I =
wish to create dynamic sql statements via HttpServletRequest which would =
result in dynamic charts, how can I pass things like cityId to this SQL =
statement??
=20
(String cityId =3D request.getParameter("city") - in JChartsApp)
=20
I would assume that my JDBC connection and query/sql statement reside in =
JChartsScriptlet class.  Is this correct??
=20
=20
Any help would greatly be appreciated :)
=20
-sky