用servlet来提取数据，并作统计，然后用jfreechart画图

指定时间范围的数据提取，并做统计：

 用servlet来提取数据，并作统计，然后用jfreechart画图。

使用的话，需要在web.xml里面配置相应的servlet,并且在index.jsp页面做引导

package drawtest_zwj;
import java.awt.Font;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartFrame;
import org.jfree.chart.ChartUtilities;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.axis.CategoryAxis;
import org.jfree.chart.axis.NumberAxis;
import org.jfree.chart.axis.ValueAxis;
import org.jfree.chart.labels.StandardCategoryItemLabelGenerator;
import org.jfree.chart.plot.CategoryPlot;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.renderer.category.BarRenderer;
import org.jfree.chart.title.TextTitle;
import org.jfree.data.category.CategoryDataset;
import org.jfree.data.category.DefaultCategoryDataset;

public class Zxt_ShowChartServlet_seasonaver extends HttpServlet {

    /**
     * 获取一个演示用的组合数据集对象
     *  
     * @return
     */
    private static CategoryDataset getDataSet() {
        DefaultCategoryDataset dataset = new DefaultCategoryDataset();
        // 从数据库中获取
        Connection conn = null;
        PreparedStatement ps_wd = null;//温度
        PreparedStatement ps_ph = null;//PH
        PreparedStatement ps_rjy=null;//溶解氧
        PreparedStatement ps_ddl=null;//电导率
        PreparedStatement ps_zd=null;//浊度
        PreparedStatement ps_gmsyzs=null;//高锰酸盐指数
        PreparedStatement ps_zl=null;//总磷
        PreparedStatement ps_zongdan=null;//总氮
        PreparedStatement ps_andan=null;//氨氮
//        PreparedStatement ps_zyjt=null;//总有机碳
        ResultSet rs_wd = null;
        ResultSet rs_ph = null;
        ResultSet rs_rjy=null;
        ResultSet rs_ddl = null;
        ResultSet rs_zd= null;
        ResultSet rs_gmsyzs=null;
        ResultSet rs_zl = null;
        ResultSet rs_zongdan = null;
        ResultSet rs_andan=null;
//        ResultSet rs_zyjt=null;
  
        try {
            Class.forName("com.mysql.jdbc.Driver"); // 加载驱动程序
            conn = DriverManager
                    .getConnection(
                            "jdbc:mysql://localhost:3306/dqz_eh_sdgc?useUnicode=true&characterEncoding=utf8",
                            "root", "root");
            //ps_wd = conn.prepareStatement("select p.name, count(pcount) from product p join salesitem si on (p.id = si.productid) group by p.id");
            //ps_wd = conn.prepareStatement("select p.name, pcount from product p join salesitem si on (p.id = si.productid) group by p.id");
            ps_wd = conn.prepareStatement("select f1, f2 from river_ey_data");
            ps_ph = conn.prepareStatement("select f1, f3 from river_ey_data");
            ps_rjy = conn.prepareStatement("select f1, f4 from river_ey_data");
            ps_ddl = conn.prepareStatement("select f1, f5 from river_ey_data");
            ps_zd = conn.prepareStatement("select f1, f6 from river_ey_data");
            ps_gmsyzs = conn.prepareStatement("select f1, f7 from river_ey_data");
            ps_zl = conn.prepareStatement("select f1, f8 from river_ey_data");
            ps_zongdan = conn.prepareStatement("select f1, f9 from river_ey_data");
            ps_andan = conn.prepareStatement("select f1, f10 from river_ey_data");
//            ps_zyjt= conn.prepareStatement("select f1, f11 from river_ey_data");
            
            rs_wd = ps_wd.executeQuery();
            rs_ph=ps_ph.executeQuery();
            rs_rjy=ps_rjy.executeQuery();
            rs_ddl = ps_ddl.executeQuery();
            rs_zd=ps_zd.executeQuery();
            rs_gmsyzs=ps_gmsyzs.executeQuery();
            rs_zl= ps_zl.executeQuery();
            rs_zongdan=ps_zongdan.executeQuery();
            rs_andan=ps_andan.executeQuery();
//            rs_zyjt=ps_zyjt.executeQuery();
/////////////////////////温度///////////////////////////////////////
              //循环前定义温度变量,
                    Double wd_value=0.00;  
                    Double jan_wd_sumvalue=0.00;//一月份温度总和值
                    Double jan_wd_aver=0.00;//一月份平均温度值
                    Integer jan_wd_count=0; //一月份记录条数
                    
                    
                    Double feb_wd_sumvalue=0.00;//2月份温度总和值
                    Double feb_wd_aver=0.00;//2月份平均温度值
                    Integer feb_wd_count=0; //2月份记录条数
                    
                    Double mar_wd_sumvalue=0.00;//3月份温度总和值
                    Double mar_wd_aver=0.00;//3月份平均温度值
                    Integer mar_wd_count=0; //3月份记录条数

                    Double apr_wd_sumvalue=0.00;//4月份温度总和值
                    Double apr_wd_aver=0.00;//4月份平均温度值
                    Integer apr_wd_count=0; //4月份记录条数
                    
                    Double may_wd_sumvalue=0.00;//5月份温度总和值
                    Double may_wd_aver=0.00;//5月份平均温度值
                    Integer may_wd_count=0; //5月份记录条数
                    
                    Double jun_wd_sumvalue=0.00;//6月份温度总和值
                    Double jun_wd_aver=0.00;//6月份平均温度值
                    Integer jun_wd_count=0; //6月份记录条数
                    
                    Double jul_wd_sumvalue=0.00;//7月份温度总和值
                    Double jul_wd_aver=0.00;//7月份平均温度值
                    Integer jul_wd_count=0; //7月份记录条数
                    
                    Double aug_wd_sumvalue=0.00;//8月份温度总和值
                    Double aug_wd_aver=0.00;//8月份平均温度值
                    Integer aug_wd_count=0; //8月份记录条数
                    
                    Double sep_wd_sumvalue=0.00;//9月份温度总和值
                    Double sep_wd_aver=0.00;//9月份平均温度值
                    Integer sep_wd_count=0; //9月份记录条数
                    
                    Double oct_wd_sumvalue=0.00;//10月份温度总和值
                    Double oct_wd_aver=0.00;//10月份平均温度值
                    Integer oct_wd_count=0; //10月份记录条数
                    
                    Double nov_wd_sumvalue=0.00;//11月份温度总和值
                    Double nov_wd_aver=0.00;//11月份平均温度值
                    Integer nov_wd_count=0; //11月份记录条数
                    
                    Double dec_wd_sumvalue=0.00;//12月份温度总和值
                    Double dec_wd_aver=0.00;//12月份平均温度值
                    Integer dec_wd_count=0; //12月份记录条数
                    
                    Double first_season_aver=0.00;//第一季度均值
                    Double second_season_aver=0.00;//第二季度均值
                    Double third_season_aver=0.00;//第三季度均值
                    Double fouth_season_aver=0.00;//第四季度均值
//=================循环读取时间-温度=================================
            while (rs_wd.next()) {
/////////////////////////日期字符串处理///////////////////////
                String DateStr=rs_wd.getString(1);//获取日期字符串
                String year=DateStr.substring(0, 4); //获取年
                String month=DateStr.substring(5,7);//获取月
                String day=DateStr.substring(8, 10);//获取日
///////////////////获取温度值///////////////////////////                     
                wd_value=rs_wd.getDouble(2);//获取温度值
                
                //System.out.println(year+"-"+month+"-"+day);//testOK
////////////////////////////处理规定日期内数据///////////////////////////
//===============================暂时处理2013年全年数据，计算月平均，画折线=======================================                
               if(year.equals("2013"))
               {
                    if(month.equals("01"))
                    { 
                        //System.out.println(year+"-"+month+"-"+day);//test_ok，年月份测试
                        jan_wd_count=jan_wd_count+1;//记录条数
                        jan_wd_sumvalue=jan_wd_sumvalue+wd_value;//1月温度累加
                    
                    }
                    else if(month.equals("02"))
                    { 
                        feb_wd_count=feb_wd_count+1;//记录条数
                        feb_wd_sumvalue=feb_wd_sumvalue+wd_value;//2月温度累加
                    }
                    else if(month.equals("03"))
                    { 
                        mar_wd_count=mar_wd_count+1;//记录条数
                        mar_wd_sumvalue=mar_wd_sumvalue+wd_value;//3月温度累加
                    }
                    else if(month.equals("04"))
                    { 
                        apr_wd_count=apr_wd_count+1;//记录条数
                        apr_wd_sumvalue=apr_wd_sumvalue+wd_value;//4月温度累加
                    }
                    else if(month.equals("05"))
                    { 
                        may_wd_count=may_wd_count+1;//记录条数
                        may_wd_sumvalue=may_wd_sumvalue+wd_value;//5月温度累加
                    }
                    else if(month.equals("06"))
                    { 
                        jun_wd_count=jun_wd_count+1;//记录条数
                        jun_wd_sumvalue=jun_wd_sumvalue+wd_value;//6月温度累加
                    }
                    else if(month.equals("07"))
                    { 
                        jul_wd_count=jul_wd_count+1;//记录条数
                        jul_wd_sumvalue=jul_wd_sumvalue+wd_value;//7月温度累加
                    }
                    else if(month.equals("08"))
                    { 
                        aug_wd_count=aug_wd_count+1;//记录条数
                        aug_wd_sumvalue=aug_wd_sumvalue+wd_value;//8月温度累加
                    }
                    else if(month.equals("09"))
                    { 
                        sep_wd_count=sep_wd_count+1;//记录条数
                        sep_wd_sumvalue=sep_wd_sumvalue+wd_value;//9月温度累加
                    }
                    else  if(month.equals("10"))
                    { 
                        oct_wd_count=oct_wd_count+1;//记录条数
                        oct_wd_sumvalue=oct_wd_sumvalue+wd_value;//10月温度累加
                    }
                    else if(month.equals("11"))
                    { 
                        nov_wd_count=nov_wd_count+1;//记录条数
                        nov_wd_sumvalue=nov_wd_sumvalue+wd_value;//11月温度累加
                    }
                  //  if(month.equals("12"))
                    else
                    { 
                        dec_wd_count=dec_wd_count+1;//记录条数
                        dec_wd_sumvalue=dec_wd_sumvalue+wd_value;//12月温度累加
                    }
               }
            }
            
            //循环结束，计算月份平均温度
        
            jan_wd_aver=jan_wd_sumvalue/jan_wd_count;
            //dataset.addValue(jan_wd_aver, "月平均温度", "2013-01");
          
            feb_wd_aver=feb_wd_sumvalue/feb_wd_count;
            //dataset.addValue(feb_wd_aver, "月平均温度", "2013-02");
            
            mar_wd_aver=mar_wd_sumvalue/mar_wd_count;
            //dataset.addValue(mar_wd_aver, "月平均温度", "2013-03");
            
            apr_wd_aver=apr_wd_sumvalue/apr_wd_count;
            //dataset.addValue(apr_wd_aver, "月平均温度", "2013-04");
            
            may_wd_aver=may_wd_sumvalue/may_wd_count;
            //dataset.addValue(may_wd_aver, "月平均温度", "2013-05");
            
            jun_wd_aver=jun_wd_sumvalue/jun_wd_count;
            //dataset.addValue(jun_wd_aver, "月平均温度", "2013-06");
            
            jul_wd_aver=jul_wd_sumvalue/jul_wd_count;
            //dataset.addValue(jul_wd_aver, "月平均温度", "2013-07");
            
            aug_wd_aver=aug_wd_sumvalue/aug_wd_count;
            //dataset.addValue(aug_wd_aver, "月平均温度", "2013-08");
            
            sep_wd_aver=sep_wd_sumvalue/sep_wd_count;
            //dataset.addValue(sep_wd_aver, "月平均温度", "2013-09");
            
            oct_wd_aver=oct_wd_sumvalue/oct_wd_count;
            //dataset.addValue(oct_wd_aver, "月平均温度", "2013-10");
            
            nov_wd_aver=nov_wd_sumvalue/nov_wd_count;
            //dataset.addValue(nov_wd_aver, "月平均温度", "2013-11");
            
            dec_wd_aver=dec_wd_sumvalue/dec_wd_count;
            //dataset.addValue(dec_wd_aver, "月平均温度", "2013-12");
            
            first_season_aver=(jan_wd_aver+feb_wd_aver+mar_wd_aver)/3;
            dataset.addValue(first_season_aver,"季度平均温度","第1季度");
            second_season_aver=(apr_wd_aver+may_wd_aver+jun_wd_aver)/3;
            dataset.addValue(second_season_aver,"季度平均温度","第2季度");
            
            third_season_aver=(jul_wd_aver+aug_wd_aver+sep_wd_aver)/3;
            dataset.addValue(third_season_aver,"季度平均温度","第3季度");
            
            fouth_season_aver=(oct_wd_aver+nov_wd_aver+dec_wd_aver)/3;
            dataset.addValue(fouth_season_aver,"季度平均温度","第4季度");
            
            
            
            rs_wd.close();
            rs_wd = null;
/*
//===========================PH==============================================
            while (rs_ph.next()) {
                dataset.addValue(rs_ph.getDouble(2), "PH", rs_ph.getString(1));
            }
            rs_ph.close();
            rs_ph = null;
//============================溶解氧============================================
            while(rs_rjy.next())
            {
                dataset.addValue(rs_rjy.getDouble(2), "溶解氧", rs_rjy.getString(1));
            }
            rs_rjy.close();
            rs_rjy=null;
//==============================电导率===============================================
//直接画图数值太大
//            while (rs_ddl.next()) {
//                dataset.addValue(rs_ddl.getDouble(2), "电导率", rs_ddl.getString(1));
//            }
//            rs_ddl.close();
//            rs_ddl = null;
//===================================浊度================================================
          //有大数
          /*
            while(rs_zd.next())
            {
                dataset.addValue(rs_zd.getDouble(2), "浊度", rs_zd.getString(1));
            }
            rs_zd.close();
            rs_zd=null;
            */
//==============================高锰酸盐指数===============================================            

/*            while (rs_gmsyzs.next()) {
                dataset.addValue(rs_gmsyzs.getDouble(2), "高锰酸盐指数", rs_gmsyzs.getString(1));
            }
            rs_gmsyzs.close();
            rs_gmsyzs = null;
*/          
//=============================总磷======================================================           
//有大数
            /*
            while(rs_zl.next())
            {
                dataset.addValue(rs_zl.getDouble(2), "总磷", rs_zl.getString(1));
            }
            
            rs_zl.close();
            rs_zl=null;
            */
//=========================总氮==============================
//有大数
 /*            while (rs_zongdan.next()) {
                dataset.addValue(rs_zongdan.getDouble(2), "总氮", rs_zongdan.getString(1));
            }
            rs_zongdan.close();
            rs_zongdan = null;
*/
//========================氨氮===============================            
/*
            while(rs_andan.next())
            {
                dataset.addValue(rs_andan.getDouble(2), "氨氮", rs_andan.getString(1));
            }
            rs_andan.close();
            rs_andan=null;
            
*/            
//========================总有机碳===============================                
//            while (rs_zyjt.next()) {
//                dataset.addValue(rs_zyjt.getDouble(2), "总有机碳", rs_zyjt.getString(1));
//            }
//            rs_zyjt.close();
//            rs_zyjt = null;
            
        } catch (SQLException e) {
            e.printStackTrace();
        }catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
        finally {
            if(ps_wd != null){
                try {
                    ps_wd.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
            if(conn != null){
                try {
                    conn.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }

        }

        return dataset;
    }

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        System.out.println("xxxx");//test
        CategoryDataset dataset = getDataSet(); //调用前面的函数，取得数据集
        JFreeChart chart = ChartFactory.createLineChart( 
                           "折线图", // 图表标题
                           "时间", // 目录轴的显示标签
                           "数值", // 数值轴的显示标签
                            dataset, // 数据集
                            PlotOrientation.VERTICAL, // 图表方向：水平、垂直
                            true,  // 是否显示图例(对于简单的柱状图必须是 false)
                            true, // 是否生成工具
                             false  // 是否生成 URL 链接
                           
                            ); 
        //中文乱码
        CategoryPlot mplot = (CategoryPlot) chart.getPlot();//获取坐标
        chart.getLegend().setItemFont(new Font("宋体", Font.PLAIN, 12));//图列
        CategoryAxis mdomainAxis = mplot.getDomainAxis(); //X坐标 
        mdomainAxis.setTickLabelFont(new Font("sans-serif", Font.PLAIN, 11));  //X
        mdomainAxis.setLabelFont(new Font("宋体", Font.PLAIN, 12));  
        
        ValueAxis mValueAxis = mplot.getRangeAxis(); 
        mValueAxis.setTickLabelFont(new Font("sans-serif", Font.PLAIN, 12));  //Y
        mValueAxis.setLabelFont(new Font("黑体", Font.PLAIN, 12));  
        
        TextTitle textTitle = chart.getTitle();//坐标标题设置
        textTitle.setFont(new Font("黑体", Font.PLAIN, 20));      
              
        FileOutputStream fos_jpg = null; //存为图片文件
        try { 
            fos_jpg = new FileOutputStream("G:\JAVA\JFreeChart\WebRoot\reports\seasonaver_wd.jpg");
           // fos_jpg = new FileOutputStream("G:\JAVA\JFreeChart\WebRoot\reports\monthaver_wd.jpg"); 
            ChartUtilities.writeChartAsJPEG(fos_jpg, 1.0f,chart,1000,500,null); 
             String path = this.getServletContext().getContextPath();
             System.out.println(path+"mmmmmmmmmmm");//test
            this.getServletContext().getRequestDispatcher("/showJfreeChart.jsp").forward(request, response);
        } finally { 
            try { 
                fos_jpg.close(); 
            } catch (Exception e) {} 
        } 
    }

}