不显示数据-jfreechat线型图的createLineChart()

Question

我用ChartFactory.createLineChar创建线型图，代码为：
 
<%
DefaultCategoryDataset dataZZ = new DefaultCategoryDataset(); 
dataZZ.addValue(1, "春季=1","春季");
dataZZ.addValue(42, "夏季=42","夏季");
dataZZ.addValue(7, "秋季=7","秋季");
dataZZ.addValue(0, "冬季=0","冬季");
 
JFreeChart chartXX = ChartFactory.createLineChart("季度统计","","数值",dataZZ,PlotOrientation.VERTICAL,true,false,false);
  chartXX.setBackgroundPaint(Color.WHITE);
  chartXX.setBorderPaint(new GradientPaint(0,0,Color.white,0,1000,Color.blue));
  CategoryPlot plotXX = chartXX.getCategoryPlot();
  plotXX.setForegroundAlpha(0.8f);
  String filenameXX=ServletUtilities.saveChartAsJPEG(chartXX,600,400,session);
  String graphURLXX=request.getContextPath()+"/servlet/DisplayChart?filename="+filenameXX;
%>
<img src="<%=graphURLXX%>" border=0 usemap="#map0">
 
 
出来的效果是没有想象中的线图，只有XY轴和平行X轴的虚线。 
我不清楚是不是某一步骤设错了，如果你知道，请赐教，谢谢。

Answer 1

用jfreechart生成3D柱状图的代码，自己挑有用的参考：
package barchart3d;import campaign.BaseCamp;
import java.awt.Dimension;
import java.awt.Color;import javax.swing.JCheckBox;
import javax.swing.JPanel;import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.axis.CategoryAxis;
import org.jfree.chart.axis.CategoryLabelPositions;
import org.jfree.chart.plot.CategoryPlot;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.renderer.category.BarRenderer3D;
import org.jfree.data.category.CategoryDataset;
import org.jfree.data.category.DefaultCategoryDataset;
import org.jfree.ui.ApplicationFrame;
import org.jfree.ui.RefineryUtilities;
import campaign.*;//public class BarChart3D extends ApplicationFrame
public class BarChart3D
{
    public JPanel jpanel;
    public BarChart3D(String[][] arrStrData) {
//super(string);//Windows Form name
        //String[][] arrStrData =  CampOption.getPictureData(myCamp);
                             /*{{"10","项目1","时间段1"},
                             {"15","项目2","时间段1"},
                             {"12","项目1","时间段2"},
                             {"16","项目2","时间段2"}};*/                            
        try{
   jpanel = createPanel(createDataset(arrStrData),"综合数据分析","季度值","数值");
   jpanel.setPreferredSize(new Dimension(500, 400));
   //setContentPane(jpanel);
        }catch(CategoryDataException e){e.printStackTrace();}
    }
    
    //生成测试数据集
    private CategoryDataset createDataset() {
DefaultCategoryDataset defaultcategorydataset
    = new DefaultCategoryDataset();
defaultcategorydataset.addValue(10.0, "增员数量", "第一季度");
defaultcategorydataset.addValue(4.0, "增员数量", "第二季度");
defaultcategorydataset.addValue(15.0, "增员数量", "第三季度");
defaultcategorydataset.addValue(14.0, "增员数量", "第四季度");
defaultcategorydataset.addValue(5.0, "新客户数量", "第一季度");
defaultcategorydataset.addValue(7.0, "新客户数量", "第二季度");
defaultcategorydataset.addValue(14.0, "新客户数量", "第三季度");
defaultcategorydataset.addValue(3.0, "新客户数量", "第四季度");
return defaultcategorydataset;
    }
    
    //根据传入的数组创建CategoryDataset数据集
    private CategoryDataset createDataset(String[][] arrStrData) throws CategoryDataException {
        if(arrStrData.length==0) throw new CategoryDataException("数组长度为零，不能创建Category数据集。");
        if(arrStrData.length>0)
        if(arrStrData[0].length != 3) throw new CategoryDataException("数组列数不为3，不能创建Category数据集。");
        DefaultCategoryDataset defaultcategorydataset
    = new DefaultCategoryDataset();
        for(int i=0;i<arrStrData.length;i++){
            if(arrStrData[i][1].length() == 0) throw new CategoryDataException("数据行"+(i+1)+"列2长度为0，不能创建Category数据集。");
            if(arrStrData[i][2].length() == 0) throw new CategoryDataException("数据行"+(i+1)+"列3长度为0，不能创建Category数据集。");
            defaultcategorydataset.addValue(Double.valueOf(arrStrData[i][0]), arrStrData[i][1], arrStrData[i][2]);
        }
        return defaultcategorydataset;
    }
    
    //生成JFreeChart对象
    private JFreeChart createChart(CategoryDataset categorydataset,
                                     String strChartName,
                                     String strAxisName,
                                     String strValueAxisName) {
JFreeChart jfreechart
    = ChartFactory.createBarChart3D(strChartName/*数据图名称*/, 
                                            strAxisName/*时间轴名称*/,
    strValueAxisName/*数值轴名称*/, 
                                            categorydataset,
    PlotOrientation.VERTICAL, true,
    true, false);
CategoryPlot categoryplot = (CategoryPlot) jfreechart.getPlot();
categoryplot.setDomainGridlinesVisible(true);
CategoryAxis categoryaxis = categoryplot.getDomainAxis();
        //设置“Category X”字样的摆放角度，以double类型的数值给出
categoryaxis.setCategoryLabelPositions
    (CategoryLabelPositions.STANDARD);//double类型的数值
    //(CategoryLabelPositions.createUpRotationLabelPositions(0.39269908169872414));
        
        //categoryaxis.setLowerMargin(0.0);//最小的Category距Value轴的距离
        //categoryaxis.setUpperMargin(0.0);//最小的Category距对面虚Value轴的距离
        //自动分割各个系列之间的距离
//categoryaxis.setCategoryMargin(0.2);//各个Category之间相对于整个时间轴长度的百分比距离
BarRenderer3D barrenderer3d
    = (BarRenderer3D) categoryplot.getRenderer();
        //barrenderer3d.setItemMargin(0.0);//各个render对象之间的距离(即各个柱体之间的距离)，不设置则自动调整
        //barrenderer3d.setWallPaint(Color.gray);//设置3D侧面墙的颜色
        //barrenderer3d.setSeriesPaint(0, Color.GREEN);//设置第一根柱体颜色
barrenderer3d.setDrawBarOutline(true);//是否画棱线(各面相交产生的线段)
return jfreechart;
    }
    
    //将JFreeChart对象包装在JPanel对象内
    public JPanel createPanel(CategoryDataset categorydataset,
                                String strChartName,
                                String strAxisName,
                                String strValueAxisName) {
JFreeChart jfreechart = createChart(categorydataset,
                                              strChartName,
                                              strAxisName,
                                              strValueAxisName);
return new ChartPanel(jfreechart);
    }
    
    public JPanel getPanel() {
return jpanel;
    }
    }