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Timeseries Chart Creation Code
From org.jfree.chart.demo.servlet.WebHitChart (See also xy_chart.jsp)
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public static String generateXYChart(String section, HttpSession session, PrintWriter pw) {
String filename = null;
try {
// Retrieve list of WebHits
WebHitDataSet whDataSet = new WebHitDataSet();
ArrayList list = whDataSet.getDataByHitDate(section);
// Throw a custom NoDataException if there is no data
if (list.size() == 0) {
System.out.println("No data has been found");
throw new NoDataException();
}
// Create and populate an XYSeries Collection
XYSeries dataSeries = new XYSeries("Hits");
Iterator iter = list.listIterator();
while (iter.hasNext()) {
WebHit wh = (WebHit)iter.next();
dataSeries.add(wh.getHitDate().getTime(),wh.getHitCount());
}
XYSeriesCollection xyDataset = new XYSeriesCollection(dataSeries);
// Create tooltip and URL generators
SimpleDateFormat sdf = new SimpleDateFormat("dd-MMM-yyyy", Locale.UK);
StandardXYToolTipGenerator ttg = new StandardXYToolTipGenerator(
StandardXYToolTipGenerator.DEFAULT_TOOL_TIP_FORMAT,
sdf, NumberFormat.getInstance());
TimeSeriesURLGenerator urlg = new TimeSeriesURLGenerator(
sdf, "pie_chart.jsp", "series", "hitDate");
// Create the chart object
ValueAxis timeAxis = new DateAxis("");
NumberAxis valueAxis = new NumberAxis("");
valueAxis.setAutoRangeIncludesZero(false); // override default
StandardXYItemRenderer renderer = new StandardXYItemRenderer(
StandardXYItemRenderer.LINES + StandardXYItemRenderer.SHAPES,
ttg, urlg);
renderer.setShapesFilled(true);
XYPlot plot = new XYPlot(xyDataset, timeAxis, valueAxis, renderer);
JFreeChart chart = new JFreeChart("", JFreeChart.DEFAULT_TITLE_FONT, plot, false);
chart.setBackgroundPaint(java.awt.Color.white);
// Write the chart image to the temporary directory
ChartRenderingInfo info = new ChartRenderingInfo(new StandardEntityCollection());
filename = ServletUtilities.saveChartAsPNG(chart, 500, 300, info, session);
// Write the image map to the PrintWriter
ChartUtilities.writeImageMap(pw, filename, info);
pw.flush();
} catch (NoDataException e) {
System.out.println(e.toString());
filename = "public_nodata_500x300.png";
} catch (Exception e) {
System.out.println("Exception - " + e.toString());
e.printStackTrace(System.out);
filename = "public_error_500x300.png";
}
return filename;
}
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