用java来画图（部分）

package com.MonKey.dao.impl;

import java.awt.Color;
import java.io.File;
import java.io.IOException;
import java.util.Date;
import java.util.List;

import org.hibernate.SessionFactory;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartUtilities;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.plot.XYPlot;
import org.jfree.chart.renderer.xy.XYLineAndShapeRenderer;
import org.jfree.chart.servlet.ServletUtilities;
import org.jfree.data.xy.XYSeries;
import org.jfree.data.xy.XYSeriesCollection;
import org.springframework.orm.hibernate3.HibernateTemplate;

import com.MonKey.dao.ElecDayDao;
import com.MonKey.dao.ElecHourCurveDao;
import com.MonKey.entity.ElecTranhour;

public class ElecHourCurveDaoImpl implements ElecHourCurveDao {
   
private HibernateTemplate template;
public void setSessionFactory(SessionFactory session) {
this.template = new HibernateTemplate(session);
}

public String getImageUrl(boolean a,boolean b,boolean c,String id) {
    
String urlstr="";
try {
List list= template.find("from ElecTranhour where id.elecTranid=?",id);
urlstr= this.getImages(a, b, c, list);
} catch (IOException e) {
e.printStackTrace();
}
return urlstr;
}

//产生小时的电流或者电压数据又或者功率
public String getImages(boolean a,boolean b,boolean c, List<ElecTranhour> list) throws IOException{

String title = "小时电流数据走势图";
        // 曲线图X轴提示
        String domain = "时间段";
        // 曲线图Y轴提示
        String range = "电流数据";

    XYSeries xsa = new XYSeries("A相电流");
        // 创建时间数据源，每一个TimeSeries在图上是一条曲线
        XYSeries xsb = new XYSeries("B相电流");
        // 创建时间数据源，每一个TimeSeries在图上是一条曲线
        XYSeries xsc = new XYSeries("C相电流");
        for (int j = 0; j < list.size(); j++) {
        ElecTranhour t= list.get(j);
        Date date= t.getId().getElecHdate();
        //电流数据图
          xsa.add(date.getHours()+j,t.getElecAcurrent());
          xsb.add(date.getHours()+j,t.getElecBcurrent());
          xsc.add(date.getHours()+j,t.getElecCcurrent());

}
        // 时间曲线数据集合
        XYSeriesCollection xysc = new XYSeriesCollection();
        xysc.removeAllSeries();
        if(a){
    xysc.addSeries(xsa);
        }
        if(b){
         xysc.addSeries(xsb);
        }
        if(c){
         xysc.addSeries(xsc);
        }
        //时间曲线元素
        JFreeChart chart = ChartFactory.createXYLineChart(title, domain, range, xysc,PlotOrientation.VERTICAL,true,true,false);
        XYPlot xyplot=(XYPlot)chart.getPlot();
        XYLineAndShapeRenderer xyl=(XYLineAndShapeRenderer) xyplot.getRenderer();
        //判断
        if(a){
        xyl.setSeriesPaint(0, new Color(255,0,0));
        if(b){
        xyl.setSeriesPaint(1, new Color(0,0,255));
        if(c)
        xyl.setSeriesPaint(2, new Color(0,255,0));
        }else{
        if(c)
        xyl.setSeriesPaint(1, new Color(0,255,0));
        }
        }else{
        if(b){
          xyl.setSeriesPaint(0, new Color(0,0,255));
          if(c)
          xyl.setSeriesPaint(1, new Color(0,255,0));
        }else{
        if(c)
          xyl.setSeriesPaint(0, new Color(0,255,0));
        }
        }
      
  
      //创建文件并将图片地址传递到页面
       String filename = ServletUtilities.saveChartAsPNG(chart,600,300,
        null,null);
String graphURL = "../displayChart?filename="+ filename;

  return graphURL;
}

}