JFreechart生成带热点的饼图

      前段时间公司要做报表开发，顺便研究了下JFreechart的简单使用，个人觉得JFreechart生成的图片效果很差，如：图像、字体模糊，缺乏动态效果，比flash相差很远。不过作为学习，跟大家交流下JFreechart的开发过程。

 

      遇到问题：

      windows下图片中文显示乱码--这个主要是由于没有给中文设置字体造成的

      某些linux下图片中文显示乱码--这个主要是由于该linux系统缺乏中文字体，向linux的字体目录下导入中文字体即可（具体方法网上很多）

      这两种问题本人已测试通过。

 

      本例使用struts2框架，导入jfreechart-1.0.13.jar和struts2-jfreechart-plugin-2.2.1.1.jar

 

1.带热点饼图的Action

com.milton.hot.FirstChart

 

package com.milton.hot;

import java.awt.Color;
import java.awt.Font;

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

import org.apache.struts2.ServletActionContext;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartRenderingInfo;
import org.jfree.chart.ChartUtilities;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.entity.StandardEntityCollection;
import org.jfree.chart.labels.StandardPieToolTipGenerator;
import org.jfree.chart.plot.PiePlot;
import org.jfree.chart.servlet.ServletUtilities;
import org.jfree.chart.title.LegendTitle;
import org.jfree.chart.title.TextTitle;
import org.jfree.chart.urls.StandardPieURLGenerator;
import org.jfree.data.general.DefaultPieDataset;

import com.opensymphony.xwork2.ActionSupport;
/**
 * 
 * 带热点的饼图
 * @author Milton
 *
 */
public class FirstChart extends ActionSupport
{
    private String mapMessage;
    private String src;
    /**
     * 生成饼图
     */
    public String execute() throws Exception
    {
        //设置数据
        DefaultPieDataset data = new DefaultPieDataset();
        data.setValue("三星I9000", 10000);
        data.setValue("HTC G7", 20000);
        data.setValue("HTC G2", 15000);
        data.setValue("诺基亚5230", 16000);
        data.setValue("摩托罗拉ME525", 50000);
        //生成JFreeChart对象
        JFreeChart chart = ChartFactory
                .createPieChart3D("手机销量统计图", data, true, true, true);

        chart.setTitle(new TextTitle("手机销量统计图", new Font("隶书", Font.BOLD, 25)));
        //建一个图例
        LegendTitle legendTitle = chart.getLegend(0);
        //设置图例字体
        legendTitle.setItemFont(new Font("宋体",Font.BOLD,14));
        
        PiePlot plot = (PiePlot) chart.getPlot();
        
        //根据key指定各个数据饼图的颜色
        plot.setSectionPaint("三星I9000", Color.RED);
        plot.setSectionPaint("HTC G7", Color.BLUE);
        plot.setSectionPaint("HTC G2", Color.GREEN);
        plot.setSectionPaint("诺基亚5230", Color.ORANGE);
        plot.setSectionPaint("摩托罗拉ME525", Color.GRAY);
        //设置plot字体
        plot.setLabelFont(new Font("宋体",Font.BOLD,18));
        //设置背景透明度（0~1）
        plot.setBackgroundAlpha(0.1f);
        
        //设置热点
        plot.setNoDataMessage("No data available");
        plot.setURLGenerator(new StandardPieURLGenerator("second.jsp", "type"));
        plot.setToolTipGenerator(new StandardPieToolTipGenerator()); 
        
        StandardEntityCollection sec = new StandardEntityCollection();

        //生成RenderingInfo实例,info参数就是图片的热点信息
        ChartRenderingInfo info = new ChartRenderingInfo(sec); 
        HttpServletRequest request = ServletActionContext.getRequest();
        String filename = ServletUtilities.saveChartAsJPEG(chart, 750, 300, info, request.getSession());
        mapMessage = ChartUtilities.getImageMap("map0", info);
        src = request.getContextPath()+"/DisplayChart?filename=" + filename;
        return "first";
    }
    public void setMapMessage(String mapMessage)
    {
        this.mapMessage = mapMessage;
    }
    public void setSrc(String src)
    {
        this.src = src;
    }
    public String getMapMessage()
    {
        return mapMessage;
    }
    public String getSrc()
    {
        return src;
    }
    
}

 2.热点链接进去后的柱状图的Action

com.milton.hot.SecondChart

 

package com.milton.hot;

import java.awt.Color;
import java.awt.Font;

import javax.servlet.http.HttpServletRequest;

import org.apache.struts2.ServletActionContext;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.axis.CategoryAxis;
import org.jfree.chart.axis.CategoryLabelPositions;
import org.jfree.chart.axis.NumberAxis;
import org.jfree.chart.labels.StandardCategoryItemLabelGenerator;
import org.jfree.chart.plot.CategoryPlot;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.renderer.category.BarRenderer3D;
import org.jfree.chart.title.TextTitle;
import org.jfree.data.category.DefaultCategoryDataset;

import com.opensymphony.xwork2.ActionSupport;

public class SecondChart extends ActionSupport
{
    private JFreeChart chart;
    
    /**
     * 生成柱状图
     */
    public String execute() throws Exception
    {
        HttpServletRequest request = ServletActionContext.getRequest();
        String type = new String(request.getParameter("type").getBytes("ISO_8859_1"), "UTF-8");
        
        if(type.equals("Java"))
        {
            //根据类型做不同处理
        }
        
        //中文必须设置字体，否则页面显示小方块
        Font xfont = new Font("宋体", Font.PLAIN, 20);// X轴  
        Font yfont = new Font("宋体", Font.PLAIN, 12);// Y轴  
        Font kfont = new Font("宋体", Font.PLAIN, 12);// 底部  
        Font titleFont = new Font("隶书", Font.BOLD, 25); // 图片标题  

        DefaultCategoryDataset data = new DefaultCategoryDataset();
        data.addValue(15000, "", "第一季度");
        data.addValue(10000, "", "第二季度");
        data.addValue(20000, "", "第三季度");
        data.addValue(5000, "", "第四季度");
        
        chart = ChartFactory.createBarChart3D(
                type+"季度销量统计图",//图表标题
                "季度",//横轴显示标签  
                "销量",//纵轴显示标签  
                data,//数据集
                PlotOrientation.VERTICAL,//设置图表方向 (水平、垂直)
                false,//是否显示图例(对于简单的柱状图必须是false)
                false,//是否生成工具
                true//是否生成URL链接
                );

        //设置标题  
        chart.setTitle(new TextTitle(type+"季度销量统计图", titleFont));

        //设置图表部分
        CategoryPlot plot = (CategoryPlot) chart.getPlot();
        plot.setForegroundAlpha(0.5f);
        CategoryAxis categoryAxis = plot.getDomainAxis();//取得横轴
        categoryAxis.setTickLabelFont(xfont);//设置横轴分类标签字体  
        categoryAxis.setLabelFont(xfont);//设置横轴显示标签的字体
        categoryAxis.setCategoryLabelPositions(CategoryLabelPositions.DOWN_45);//分类标签以45度倾斜

        NumberAxis numberAxis = (NumberAxis) plot.getRangeAxis();//取得纵轴
        numberAxis.setTickLabelFont(yfont);//设置纵轴分类标签字体  
        numberAxis.setLabelFont(yfont);//设置纵轴显示标签字体

        //渲染柱子
        BarRenderer3D render = (BarRenderer3D) plot.getRenderer();
        render.setSeriesPaint(0, Color.blue);//设置柱子颜色
        render.setSeriesPaint(1, Color.BLUE);
        render.setSeriesPaint(2, Color.RED);
        render.setSeriesPaint(3, Color.GREEN);
        render.setItemMargin(0.5);//设置柱子间隔
        render.setBaseItemLabelGenerator(new StandardCategoryItemLabelGenerator());
        render.setBaseItemLabelsVisible(true);//显示每个柱子的数值
        plot.setRenderer(render);
        return SUCCESS;
    }

    public JFreeChart getChart()
    {
        return chart;
    }

    public void setChart(JFreeChart chart)
    {
        this.chart = chart;
    }
    
}

 3.web.xml配置

 

	<servlet>
		<servlet-name>DisplayChart</servlet-name>
		<servlet-class>org.jfree.chart.servlet.DisplayChart</servlet-class>
	</servlet>
	<servlet-mapping>
		<servlet-name>DisplayChart</servlet-name>
		<url-pattern>/DisplayChart</url-pattern>
	</servlet-mapping>

 

 4.struts.xml配置

 

        <action name="firstChart" class="com.milton.hot.FirstChart">
                <result name="first">/first.jsp</result>
        </action>
        <action name="secondChart" class="com.milton.hot.SecondChart">
         <result type="chart">
         	<param name="width">500</param>
		<param name="height">500</param>
		<param name="imageType">jpg</param>
         </result>
        </action>

 5.first.jsp的<body>中添加如下代码

 

<p align="center">
<s:property value="mapMessage" escape="false"/>
<img src="<s:property value='src'/>" border=0 usemap="#map0">
</p>

 6.second.jsp（热点链接进入后的柱状图页面）

 

<body>
<!-- 得到饼图热点类型 -->
<%
    String type = request.getParameter("type");
    String str = new String(type.getBytes("ISO_8859_1"), "utf-8");
%>
<%=str%>
<p align="center"><img
	src="<%=request.getContextPath()%>/secondChart.action?type=<%=str%>">
</p>
</body>

 7.部署在web服务器后运行

 8.浏览器输入http://10.0.0.46:8080/JFreeChart/firstChart.action后即可看到first.jsp中带热点的饼图

 9.点击热点区域即可看到对应的柱状图