J显示柱状图？

Question

package menubar;import java.awt.*;
import com.borland.jbcl.layout.*;
import javax.swing.*;
import org.jfree.chart.demo.*;
import org.jfree.ui.RefineryUtilities;public class queryblock extends JFrame {
  private XYLayout xYLayout1 = new XYLayout();
  private JLabel jLabel1 = new JLabel();
  private JComboBox jComboBox1 = new JComboBox();
  private Button button1 = new Button();
  private Button button2 = new Button();  public queryblock() {
    try {
      jbInit();
    }
    catch(Exception e) {
      e.printStackTrace();
    }
  }
  private void jbInit() throws Exception {
    jLabel1.setFont(new java.awt.Font("Dialog", 0, 16));
    jLabel1.setText("请选择小区：");
    this.getContentPane().setLayout(xYLayout1);
    jComboBox1.setFont(new java.awt.Font("SansSerif", 0, 16));
    button1.setFont(new java.awt.Font("Dialog", 0, 16));
    button1.setLabel("查询");
    button2.setLabel("取消");
    button2.setFont(new java.awt.Font("Dialog", 0, 16));
    this.getContentPane().add(jLabel1, new XYConstraints(22, 36, 101, 26));
    this.getContentPane().add(jComboBox1, new XYConstraints(117, 36, 111, 26));
    this.getContentPane().add(button1,     new XYConstraints(243, 33, 70, 28));
    this.getContentPane().add(button2,    new XYConstraints(322, 32, 70, 28));
  }
  public static void  main(String[] args) {     VerticalBarChartDemo demo = new VerticalBarChartDemo("Vertical Bar Chart Demo",new String[]{"one","two","three","four"});
     demo.pack();
     RefineryUtilities.centerFrameOnScreen(demo);
     demo.setVisible(true);    }
}/* ======================================
 * JFreeChart : a free Java chart library
*/package org.jfree.chart.demo;import java.awt.Color;import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.axis.HorizontalCategoryAxis;
import org.jfree.chart.axis.NumberAxis;
import org.jfree.chart.plot.CategoryPlot;
import org.jfree.data.DefaultCategoryDataset;
import org.jfree.ui.ApplicationFrame;
import org.jfree.ui.RefineryUtilities;/**
 * A simple demonstration application showing how to create a vertical bar chart.
 *
 * @author David Gilbert
 */
public class VerticalBarChartDemo extends ApplicationFrame {    /**
     * Creates a new demo instance.
     *
     * @param title  the frame title.
     */
    public VerticalBarChartDemo(String title,String Lcategory[]) {        super(title);        String category[]=new String[Lcategory.length+1];
        // row keys...        String series1 = "First";
        String series2 = "Second";
        String series3 = "Third";        // column keys...
        for(int i=0;i<Lcategory.length;i++){          category[i+1]=Lcategory[i];
        }
        // create the dataset...
        DefaultCategoryDataset dataset = new DefaultCategoryDataset();        dataset.addValue(1.0, series1, category[1]);
        dataset.addValue(4.0, series1, category[2]);
        dataset.addValue(3.0, series1, category[3]);
        dataset.addValue(5.0, series1, category[4]);
        dataset.addValue(5.0, series2, category[1]);
        dataset.addValue(7.0, series2, category[2]);
        dataset.addValue(6.0, series2, category[3]);
        dataset.addValue(8.0, series2, category[4]);
        dataset.addValue(4.0, series3, category[1]);
        dataset.addValue(3.0, series3, category[2]);
        dataset.addValue(2.0, series3, category[3]);
        dataset.addValue(3.0, series3, category[4]);        // create the chart...
        JFreeChart chart = ChartFactory.createVerticalBarChart(
                                                     "Vertical Bar Chart",  // chart title
                                                     "Category",            // domain axis label
                                                     "Value",               // range axis label
                                                     dataset,               // data
                                                     true,                  // include legend
                                                     true,
                                                     false
                                                 );        // NOW DO SOME OPTIONAL CUSTOMISATION OF THE CHART...        // set the background color for the chart...
        chart.setBackgroundPaint(new Color(0xBBBBDD));        // get a reference to the plot for further customisation...
        CategoryPlot plot = chart.getCategoryPlot();        // skip some labels if they overlap...
        HorizontalCategoryAxis domainAxis = (HorizontalCategoryAxis) plot.getDomainAxis();
        domainAxis.setSkipCategoryLabelsToFit(true);        // set the range axis to display integers only...
        NumberAxis rangeAxis = (NumberAxis) plot.getRangeAxis();
        rangeAxis.setStandardTickUnits(NumberAxis.createIntegerTickUnits());        // OPTIONAL CUSTOMISATION COMPLETED.        // add the chart to a panel...
        ChartPanel chartPanel = new ChartPanel(chart);
        chartPanel.setPreferredSize(new java.awt.Dimension(500, 270));
        setContentPane(chartPanel);    }    /**
     * Starting point for the demonstration application.
     *
     * @param args  ignored.
     */
    public static void  main(String[] args) {        VerticalBarChartDemo demo = new VerticalBarChartDemo("Vertical Bar Chart Demo",new String[]{"one","two","three","four"});
        demo.pack();
        RefineryUtilities.centerFrameOnScreen(demo);
        demo.setVisible(true);    }}
怎么无法显示柱状图？