jfreechart时间类型的曲线

<%@ page contentType="text/html;charset=GBK"%>
<%@ page import = "org.jfree.chart.ChartFactory,
                  org.jfree.chart.ChartPanel,
                  org.jfree.chart.JFreeChart,
                  org.jfree.chart.StandardLegend,
                  org.jfree.chart.axis.NumberAxis,
  org.jfree.chart.plot.CategoryPlot,
  org.jfree.chart.plot.PlotOrientation,
  org.jfree.chart.renderer.LineAndShapeRenderer,
  org.jfree.data.CategoryDataset,
  org.jfree.data.DefaultCategoryDataset,
  org.jfree.chart.servlet.ServletUtilities
"%>
<%
       
       // row keys...
       String series1 = "First";
       String series2 = "Second";
       String series3 = "Third";

       // column keys...
       String type1 = "Type 1";
       String type2 = "Type 2";
       String type3 = "Type 3";
       String type4 = "Type 4";
       String type5 = "Type 5";
       String type6 = "Type 6";
       String type7 = "Type 7";
       String type8 = "Type 8";

       // create the dataset...
       DefaultCategoryDataset dataset = new DefaultCategoryDataset();

       dataset.addValue(1.0, series1, type1);
       dataset.addValue(4.0, series1, type2);
       dataset.addValue(3.0, series1, type3);
       dataset.addValue(5.0, series1, type4);
       dataset.addValue(5.0, series1, type5);
       dataset.addValue(7.0, series1, type6);
       dataset.addValue(7.0, series1, type7);
       dataset.addValue(8.0, series1, type8);

       dataset.addValue(5.0, series2, type1);
       dataset.addValue(7.0, series2, type2);
       dataset.addValue(6.0, series2, type3);
       dataset.addValue(8.0, series2, type4);
       dataset.addValue(4.0, series2, type5);
       dataset.addValue(4.0, series2, type6);
       dataset.addValue(2.0, series2, type7);
       dataset.addValue(1.0, series2, type8);

       dataset.addValue(4.0, series3, type1);
       dataset.addValue(3.0, series3, type2);
       dataset.addValue(2.0, series3, type3);
       dataset.addValue(3.0, series3, type4);
       dataset.addValue(6.0, series3, type5);
       dataset.addValue(3.0, series3, type6);
       dataset.addValue(4.0, series3, type7);
       dataset.addValue(3.0, series3, type8);   
   
         
       // create the chart...
       JFreeChart chart = ChartFactory.createLineChart(
           "血压水平分布图",       // chart title
           "Type",                    // domain axis label
           "Value",                   // range axis label
           dataset,                   // data
           PlotOrientation.VERTICAL,  // orientation
           true,                      // include legend
           true,                      // tooltips
           false                      // urls
       );

       // NOW DO SOME OPTIONAL CUSTOMISATION OF THE CHART...
       StandardLegend legend = (StandardLegend) chart.getLegend();
       legend.setDisplaySeriesShapes(true);
       legend.setShapeScaleX(1.5);
       legend.setShapeScaleY(1.5);
       legend.setDisplaySeriesLines(true);   
       CategoryPlot plot = chart.getCategoryPlot();
       // customise the range axis...
       NumberAxis rangeAxis = (NumberAxis) plot.getRangeAxis();
       rangeAxis.setStandardTickUnits(NumberAxis.createIntegerTickUnits());
       rangeAxis.setAutoRangeIncludesZero(true);
       rangeAxis.setUpperMargin(0.20);
       rangeAxis.setLabelAngle(Math.PI / 2.0);    
       LineAndShapeRenderer renderer = (LineAndShapeRenderer) plot.getRenderer();  

       renderer.setItemLabelsVisible(true);          
     
 
String filename = ServletUtilities.saveChartAsPNG(chart, 500, 300, null, session);
String graphURL = request.getContextPath() + "/DisplayChart?filename=" + filename;
%>
<img src="<%= graphURL %>" width=500 height=300 border=0 usemap="#<%= filename %>"