JFreeChart中的波浪图_JAVA_编程开发_程序员俱乐部

在Servlet中的代码:

package com.lyb.pic;

import java.awt.BasicStroke;
import java.awt.Font;
import java.io.IOException;

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

import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartUtilities;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.plot.XYPlot;
import org.jfree.chart.renderer.xy.XYLineAndShapeRenderer;
import org.jfree.data.general.SeriesException;
import org.jfree.data.time.Day;
import org.jfree.data.time.TimeSeries;
import org.jfree.data.time.TimeSeriesCollection;
import org.jfree.data.xy.XYDataset;

public class Time extends HttpServlet{

public voiddoGet(HttpServletRequest request,HttpServletResponse response)throws IOException {
  doPost(request,response);
}
public void doPost(HttpServletRequestrequest,HttpServletResponse response) throws IOException {
  //设置返回类型
  response.setContentType("image/png");
  //设置返回字体
  response.setCharacterEncoding("utf-8");
  //获取数据集对象
  XYDataset xyd =getData();
  // 创建图形对象
  JFreeChart jfc =ChartFactory.createTimeSeriesChart("时序图","POLO历史价格", "价格", xyd,true, true, false);
  //设置标题字体，防止中文乱码
  jfc.getTitle().setFont(newFont("黑体", 0, 15));
  //设置图例的字体，防止中文乱码
  jfc.getLegend().setItemFont(newFont("黑体", 0, 15));
  //获取图表区域对象
  XYPlot xyplot = (XYPlot)jfc.getPlot();
  //设置横轴标签的字体，防止中文乱码
  xyplot.getDomainAxis().setLabelFont(newFont("黑体", 0, 15));
  //设置竖轴标签的字体，防止中文乱码
  xyplot.getRangeAxis().setLabelFont(newFont("黑体", 0, 15));
  //获得折线显示对象
  XYLineAndShapeRendererxylineandshaperenderer = new XYLineAndShapeRenderer();
  //设置不显示折线
  xylineandshaperenderer.setBaseShapesVisible(false);
  //设置折线的粗细
  xylineandshaperenderer.setSeriesStroke(0,new BasicStroke(0.5F, 1, 1, 5F, new float[] { 5F, 10F },0.0F));
  xyplot.setRenderer(xylineandshaperenderer);
 
  // 将图表已数据流的方式返回给客户端
  ChartUtilities.writeChartAsPNG(response.getOutputStream(),jfc,500, 270);
}

private static XYDataset getData() {
  //创建时序对象
  TimeSeries timeseries = newTimeSeries("动画");
  //初始化日期为1990年1月1日
  Day day = new Day(1, 1,1990);
  double d = 100D;
  //添加数据，用于标识横轴的显示数字
  for (int i = 0; i< 4000; i++)
   try {
    //随机取出100附近数
    d= (d + Math.random()) - 0.5D;
    //添加到时序对象
    timeseries.add(day,new Double(d));
    //之后的一天
    day= (Day) day.next();
   } catch(SeriesException seriesexception) {

   }
  //返回XYDataset数据集
  return newTimeSeriesCollection(timeseries);
}
}



产生的假数据:

package com.lovo.pic;

import java.util.Random;

public class DataUtils {

private static Random random = newRandom();
private static final int NUMBER = 100;
public static int getNumber() {
  returnrandom.nextInt(NUMBER);
}
}



在xml中的代码：

<servlet>
   <servlet-name>time</servlet-name>
   <servlet-class>com.lovo.pic.Time</servlet-class>
</servlet>
<servlet-mapping>
   <servlet-name>time</servlet-name>
   <url-pattern>/time</url-pattern>
</servlet-mapping>