//生成柱状图
        try{
         int j=0;
         Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
         Connection con=DriverManager.getConnection("jdbc:odbc:aaa");
         Statement sql=con.createStatement();
         ResultSet rs=sql.executeQuery("select * from test");
         DefaultCategoryDataset dataset=new DefaultCategoryDataset();//设置数据源

         while(rs.next()){
         dataset.addValue(Integer.parseInt(rs.getString("dq")),"学校",area[j]);
         //添加数据，参数包括名称和数值
         j++;
         }

         JFreeChart chart1=ChartFactory.createBarChart3D("统计图","招生地区","招生人数",
                dataset,PlotOrientation.VERTICAL,false,false,false);

         CategoryPlot plot=chart1.getCategoryPlot();
      
         BarRenderer3D renderer1=new BarRenderer3D();
      
         renderer1.setItemLabelsVisible(true);//显示每个柱子上的数据
       
         renderer1.setItemMargin(0.1);//设置每个柱子之间的距离
         plot.setRenderer(renderer1);//让上面对柱子的设置生效
        String filename=ServletUtilities.saveChartAsJPEG(chart1,300,200,session);
         //生成图片，包括图片的大小

         session.setAttribute("file_name2",filename);
         String URL=request.getContextPath()+"/servlet/DisplayChart?filename="+filename;

         session.setAttribute("file_url2",URL);

         }catch(SQLException e){}

%>
<center><img src="<%=session.getAttribute("file_url1")%>" width=300 height=200 border=0 usemap="#<%=session.getAttribute("file_name1") %>">

<img src="<%=session.getAttribute("file_url2") %>" width=300 height=200 border=0 usemap="#<%=session.getAttribute("file_name2")%>"></center>

</html>