public String generateBarChart(
String hitSection, HttpSession session, PrintWriter pw, String courseId, int studentId) {
/* int groupId=0;
if (groupName.equals("All")){
groupId=0;
}else{
groupId = studStatisticBean.getGroupIdByName(groupName);
}*/
String filename = null;
try {
// Retrieve list of WebHits
StudentsConceptChartDataSet cDataSet =
new StudentsConceptChartDataSet(studStatisticBean, courseId, studentId);
ArrayList list = cDataSet.getDataBySection(hitSection);
// 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 a CategoryDataset
Iterator iter = list.listIterator();
DefaultCategoryDataset dataSet = new DefaultCategoryDataset();
while (iter.hasNext()) {
StudentsConceptHit wh = (StudentsConceptHit) iter.next();
// Comparable c1= Double.parseDouble(wh.getHitDegree());
dataSet.addValue(
wh.getHitDegree(),
"degree of mastery for concept ",
String.valueOf(wh.getHitConcept()));
}
// Create the chart object
CategoryAxis categoryAxis = new CategoryAxis("Concepts");
ValueAxis valueAxis = new NumberAxis("Degree of Mastery");
valueAxis.setRange(0.0, 6.0);
categoryAxis.setCategoryLabelPositions(
new CategoryLabelPositions().createUpRotationLabelPositions(45));
BarRenderer renderer = new BarRenderer();
renderer.setDrawBarOutline(true);
renderer.setItemURLGenerator(
new StandardCategoryURLGenerator("xy_chart.jsp", "series", "section"));
StandardCategoryToolTipGenerator scttg = new StandardCategoryToolTipGenerator();
renderer.setToolTipGenerator(scttg);
Plot plot = new CategoryPlot(dataSet, categoryAxis, valueAxis, renderer);
JFreeChart chart = new JFreeChart("", JFreeChart.DEFAULT_TITLE_FONT, plot, true);
chart.setBackgroundPaint(java.awt.Color.white);
// Write the chart image to the temporary directory
ChartRenderingInfo info = new ChartRenderingInfo(new StandardEntityCollection());
filename = ServletUtilities.saveChartAsPNG(chart, 600, 400, 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;
}