JFreeChar初探

   今天用JFreeChar整了一下报表,感觉还不错,先整理如下:

   具体效果见上传的图片;

代码如下:

1 前台页面:

<%@ page contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" %>
请选择要生成的图形报表<br>
<select id='charid' onchange="makeChar()">
  <option value="0">请选择一种图表</option>
<option value="Pie">PieChart</option>
<option value="Bar">BarChart3D</option>
<option value="Line">LineChart</option>
</select>
<div id="displayDiv"></div>
<script type="text/javascript" language="javascript">
function makeChar(){
       
     
      var charType=document.getElementById("charid").value;
      if(charType==0){
        return; 
      }else{
         
        
          var imgdiv=document.getElementById("displayDiv");
          imgdiv.innerHTML="";
          var img=document.createElement("img");
         // img.setAttribute("src","servlet/ChartServlet?chartType="+charType);
          img.setAttribute("src","myCharServlet?charType="+charType);
          //imageZone.setAttribute('src',"servlet/ChartServlet?chartType="+cType);
          imgdiv.appendChild(img);
      }
     

}

</script>

 

 

后台代码:

package cn.netjava.jFreeChart;

import java.io.IOException;
import java.io.OutputStream;

import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.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.PlotOrientation;
import org.jfree.data.category.DefaultCategoryDataset;
import org.jfree.data.general.DefaultPieDataset;

public class MyCharServlet extends HttpServlet {


	protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		//super.service(arg0, arg1);
		System.out.println("到了myCharServlet了");
		//response.setContentType("image/png;charset=UTF-8");
		response.setHeader("Cache-Control", "no-cache");
		response.setContentType("image/png");
		String chartType=request.getParameter("charType").trim();
        JFreeChart jFreeChart=getCharByType(chartType);
        
        if(jFreeChart!=null){
        	OutputStream os=response.getOutputStream();
           ChartUtilities.writeChartAsPNG(os, jFreeChart, 500, 300);
          os.flush();
          os.close();
        }
		
		
		
		
	}
	

	public JFreeChart getCharByType(String charType){
		JFreeChart jfChart=null;
		if(charType.equalsIgnoreCase("pie")){
		  //饼图
		  DefaultPieDataset dataSet=new DefaultPieDataset();
		  dataSet.setValue("java", new Integer(55));
		  dataSet.setValue("c++", new Integer(30));
		  dataSet.setValue("delphi", new Integer(15));
		

			//DefaultPieDataset dataSet=	getPieDataSet();
		  
		  
		  jfChart=ChartFactory.createPieChart("各语言使用人数统计表", dataSet, true, false, false);
		  
			
			
		}else if(charType.equalsIgnoreCase("line")){
			DefaultCategoryDataset dataSet=new DefaultCategoryDataset();
			
			String groups[]={"曼联","利物浦","阿森纳"};
			String round[]={"第一轮","第二轮","第三轮","第四轮","第五轮","第六轮"};
			for (int i = 0; i < round.length; i++) {
				for (int j = 0; j < groups.length; j++) {
					dataSet.setValue(new java.util.Random().nextInt(5),groups[j] , round[i]);
				}
			}
			
			jfChart=ChartFactory.createLineChart("08/09赛季英超球队积分榜(前六轮)", "球队", "排名", dataSet, PlotOrientation.VERTICAL, true, false, false);
		}else if(charType.equalsIgnoreCase("bar")){
			 String citys[]={"北京","上海","广州"};
			 String months[]={"一月","二月","三月"};
			 DefaultCategoryDataset dataset=new DefaultCategoryDataset();
			 for (int i = 0; i < months.length; i++) {
				for (int j = 0; j < citys.length; j++) {
					dataset.setValue(new java.util.Random().nextInt(1000), citys[j], months[i]);
				}
			}
			
			jfChart=ChartFactory.createBarChart3D("2009年中国三大城市降水量表（第一季度）", "城市", "降水量", dataset, PlotOrientation.VERTICAL, true, false, false);
			
		}
		
		
		return jfChart;
	}
	
	
	
	
	public static DefaultPieDataset getPieDataSet() {
		// 用来填充pie图的数据集
		DefaultPieDataset dataset = new DefaultPieDataset();
		// 饼图分块名字
		String[] seriesNames = { "芙蓉路", "八一路", "五一路", "大学路", };
		for (int i = 0; i < seriesNames.length; i++) {
			int value = new java.util.Random().nextInt(1000) + 500;
			// 设置pie数据集中的数据对
			dataset.setValue(seriesNames[i], value);
		}
		return dataset;
	}
}