title: JFree chart by using servlet in jsp
body: <p>How can i draw a line chart by using Servlets and rendered Image?
  I wrote a servlet and create a chart.but i don't know how to display it on my jsp page.</p>
  
  <p>my servlet code:</p>
  
  <pre><code>public class GraphGen extends HttpServlet {
  
      public void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
  
          genGraph(req, resp);
      }
  
      public void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
          genGraph(req, resp);
      }
  
      @SuppressWarnings("deprecation")
      public void genGraph(HttpServletRequest req, HttpServletResponse resp) {
  
          try {
              OutputStream out = resp.getOutputStream();
  
              // Create a simple Bar chart
              System.out.println("Setting dataset values");
  
              DefaultCategoryDataset dataset = new DefaultCategoryDataset();
              dataset.setValue(30, "Girls","SCIENCE CLASS");
              dataset.setValue(30,  "Boys","SCIENCE CLASS");
              dataset.setValue(10,  "Girls","ECONOMICS CLASS");
              dataset.setValue(50, "Boys","ECONOMICS CLASS");
              dataset.setValue(5, "Girls","LANGUAGE CLASS");
              dataset.setValue(55, "Boys","LANGUAGE CLASS");
  
              JFreeChart chart = ChartFactory.createBarChart3D(
                  "Comparison between Girls and Boys in Science," + "Economics and Language classes",
                  "Students Comparisons", "No of Students",
                  dataset,
                  PlotOrientation.VERTICAL,
                  true,
                  true,
                  false);
  
              chart.setBackgroundPaint(Color.white);
  
              // Set the background colour of the chart
              chart.getTitle().setPaint(Color.blue);
  
              // Adjust the colour of the title
              CategoryPlot plot = chart.getCategoryPlot();
  
              // Get the Plot object for a bar graph
              plot.setBackgroundPaint(Color.white);
              plot.setRangeGridlinePaint(Color.red);
  
              CategoryItemRenderer renderer = plot.getRenderer();
              renderer.setSeriesPaint(0, Color.red);
              renderer.setSeriesPaint(1, Color.green);
              renderer.setItemURLGenerator(
                  new StandardCategoryURLGenerator(
                      "index1.html",
                      "series",
                      "section"));
              renderer.setToolTipGenerator(new StandardCategoryToolTipGenerator());
  
              resp.setContentType("image/png");
  
              ChartUtilities.writeChartAsPNG(out, chart, 625, 500);
  
          } catch (Exception e) {
              System.err.println("Problem occurred creating chart." + e.getMessage());
          }
      }
  </code></pre>