import java.awt.Color;
import java.io.IOException;
import java.text.SimpleDateFormat;

import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartUtilities;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.axis.DateAxis;
import org.jfree.chart.axis.DateTickUnit;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.plot.XYPlot;
import org.jfree.data.time.Day;
import org.jfree.data.time.Hour;
import org.jfree.data.time.Month;
import org.jfree.data.time.TimeSeries;
import org.jfree.data.time.TimeSeriesCollection;
import org.jfree.data.xy.XYDataset;
import org.jfree.ui.RectangleInsets;

/**
 * 用于将统计结果显示成走势图
 * @author lord
 * 调用方法：
   TrendChart trendChart = new TrendChart();
   trendChart.chartTitle = "走势图";
   trendChart.chartSeriesDesc = "走势曲线";
   trendChart.chartXdesc = "时间";
   trendChart.chartYdesc = "价格";
   trendChart.graphHigh = 400;
   trendChart.graphWidth = 600;
   trendChart.timeFormat = "yyyy-MM";
   trendChart.periodType = TrendChart.DAY;
   ......
   trendChart.addTimeSeriesUnitData(mYear, mMonth, mDay, mHour, (int)rData);
   trendChart.createTrendGraphByServlet(request, response);
 */

public class TrendChart {
  public final static String MONTH = "MONTH";
  public final static String DAY = "DAY";
  public final static String HOUR = "HOUR";
 
  private JFreeChart rChart = null;     //图表对象
  public String chartTitle = "";        //图表标题
  public String chartXdesc = "";        //X轴标题
  public String chartYdesc = "";        //Y轴标题
  public String chartSeriesDesc = "";   //曲线说明
  public int graphWidth = 600;          //默认宽度
  public int graphHigh = 400;           //默认高度
  public String timeFormat = "MM/yyyy"; // 按日：MM-dd ,按小时：hh:mm

  // 用于标志用户选择的是按哪种查询统计周期类型(年、月、天、小时).
  // 年：YEAR, 月：MONTH, 天：DAY, 小时：HOUR
  public String periodType = "";

  // 用于确定时间间隔
  public int dateInterval = 0;
 
  //统计结果数据集
  TimeSeriesCollection statDataset = new TimeSeriesCollection();
 
  TimeSeries monthSeries = null;  //月份统计图数据集合
  TimeSeries daySeries = null;    //天数统计图数据集合
  TimeSeries hourSeries = null;   //小时统计图数据集合
  
  
  /**
   * 创建Servlet方式走势图表
   * @param req
   * @param res
   * @throws IOException
   */
  public void createTrendGraphByServlet(ServletRequest req, ServletResponse res) throws IOException {
    res.setContentType("image/jpeg");
    setTimeSeriesStatType();
    rChart = createTrendChart();
    ChartUtilities.writeChartAsJPEG(res.getOutputStream(), 1, rChart, graphWidth, graphHigh, null);
  }
 
  /**
   * 创建趋势图表
   * @return JFreeChart 图表对象JFreeChart
   */
  private JFreeChart createTrendChart(){
    JFreeChart _freeChart = ChartFactory.createTimeSeriesChart(chartTitle, chartXdesc, chartYdesc,
        getTimeSeriesStatDataSet(), true, false, false);
    _freeChart.setBackgroundPaint(Color.white);
   
    XYPlot _xyplot = _freeChart.getXYPlot();
    _xyplot.setOrientation(PlotOrientation.VERTICAL);
    _xyplot.setBackgroundPaint(Color.lightGray);
    _xyplot.setDomainGridlinePaint(Color.white);
    _xyplot.setRangeGridlinePaint(Color.white);
    _xyplot.setAxisOffset(new RectangleInsets(1.0, 2.0, 2.0, 10.0));
   
    DateAxis dateaxis = (DateAxis) _xyplot.getDomainAxis();
    if (periodType.equalsIgnoreCase("MONTH")){
      if (dateInterval > 0) {
        dateaxis.setTickUnit(new DateTickUnit(DateTickUnit.MONTH, dateInterval));
      }
    }else if (periodType.equalsIgnoreCase("DAY")){
      if (dateInterval > 0) {
        dateaxis.setTickUnit(new DateTickUnit(DateTickUnit.DAY, dateInterval));
      }
    }else if (periodType.equalsIgnoreCase("HOUR")){
      if (dateInterval > 0) {
        dateaxis.setTickUnit(new DateTickUnit(DateTickUnit.HOUR, dateInterval));
      }
    }
    dateaxis.setDateFormatOverride(new SimpleDateFormat(timeFormat));
    return _freeChart;
  }
 
  /**
   * 增加走势图数据
   * @param periodType 区间类型
   * @param year  年份
   * @param month 月份
   * @param day   日期
   * @param hour  时间
   * @param statData 统计数据
   */
  public void addTimeSeriesUnitData(int year, int month, int day, int hour, int statData) {
    if (periodType.equalsIgnoreCase("MONTH")){
      if (monthSeries == null){
        monthSeries = new TimeSeries(chartSeriesDesc, Month.class);
      }
      monthSeries.add(new Month(month, year), statData);
    }else if (periodType.equalsIgnoreCase("DAY")){
      if (daySeries == null){
        daySeries = new TimeSeries(chartSeriesDesc, Day.class);
      }
      daySeries.add(new Day(day, month, year), statData);
    }else if (periodType.equalsIgnoreCase("HOUR")){
      if (hourSeries == null){
        hourSeries = new TimeSeries(chartSeriesDesc, Hour.class);
      }
      hourSeries.add(new Hour(hour, day, month, year), statData);
    }
  }
 
  /**
   * 设置走势图统计的区间类型
   * @param periodType 区间类型
   */
  private void setTimeSeriesStatType() {
    if (periodType.equalsIgnoreCase("MONTH")){
      statDataset.addSeries(monthSeries);
    }else if (periodType.equalsIgnoreCase("DAY")){
      statDataset.addSeries(daySeries);
    }else if (periodType.equalsIgnoreCase("HOUR")){
      statDataset.addSeries(hourSeries);
    }
  }
 
  /**
   * 获得时序图的统计数据
   * @return XYDataset 统计数据
   */
  private XYDataset getTimeSeriesStatDataSet() {
    statDataset.setDomainIsPointsInTime(true);
    return statDataset;
  }

  public int getDateInterval() {
    return dateInterval;
  }

  public void setDateInterval(int dateInterval) {
    this.dateInterval = dateInterval;
  }


JSP调用代码如下：
 TrendChart trendChart = new TrendChart();
 trendChart.chartTitle = "一年走势图";
 trendChart.chartSeriesDesc = "走势曲线";
 trendChart.chartXdesc = "时间";
 trendChart.chartYdesc = "价格";
 trendChart.graphHigh = 400;
 trendChart.graphWidth = 600;
 trendChart.timeFormat = "yyyy-MM";
 trendChart.periodType = TrendChart.DAY;
 
 double baseData = 100.0;
 double rData = baseData;
 java.util.Calendar calendar = java.util.Calendar.getInstance();
 calendar.set(2007, 0, 0);
 for (int i = 1; i <= 365; i++){
  rData = rData * (1 + (Math.random() - 0.495) / 10.0);
  calendar.add(java.util.Calendar.DAY_OF_MONTH, 1);
  System.out.println(calendar.get(java.util.Calendar.YEAR) + "||" +
   (calendar.get(java.util.Calendar.MONTH) + 1) + "||" + calendar.get(java.util.Calendar.DAY_OF_MONTH) + "||" +
   (calendar.get(java.util.Calendar.HOUR_OF_DAY) + "||" + calendar.get(java.util.Calendar.MINUTE))
  );
  int mYear = calendar.get(java.util.Calendar.YEAR);
  int mMonth = calendar.get(java.util.Calendar.MONTH) + 1;
  int mDay = calendar.get(java.util.Calendar.DAY_OF_MONTH);
  int mHour = calendar.get(java.util.Calendar.HOUR_OF_DAY);
  trendChart.addTimeSeriesUnitData(mYear, mMonth, mDay, mHour, (int)rData);
 }
trendChart.createTrendGraphByServlet(request, response);

显示图结果如下：