jfreechart生成图表

迈不过友情╰ 2022-08-27 05:47 197阅读 0赞

JFreeChart是JAVA平台上的一个开放的图表绘制类库。它完全使用JAVA语言编写，是为applications, applets, servlets 以及JSP等使用所设计。JFreeChart可生成饼图（pie charts）、柱状图（bar charts）、[散点图][Link 1]（scatter plots）、[时序图][Link 2]（time series）、[甘特图][Link 3]（Gantt charts）等等多种图表，并且可以产生PNG和[JPEG格式][JPEG]的输出，还可以与PDF和EXCEL关联。

使用前要导入jar包

![Center][]

下面是一点简单的例子：

1，生成饼图

package cn.itcast.jfreechart;
    
    import java.awt.Font;
    import java.io.File;
    
    import javax.imageio.ImageIO;
    
    import org.jfree.chart.ChartFactory;
    import org.jfree.chart.ChartUtilities;
    import org.jfree.chart.JFreeChart;
    import org.jfree.chart.labels.StandardPieSectionLabelGenerator;
    import org.jfree.chart.plot.PiePlot;
    import org.jfree.data.general.DefaultPieDataset;
    
    public class App {
    	
    	public static void main(String[] args) throws Exception {
    		//
    		String title = "各大公司JEE AS市场占有率统计" ;
    		DefaultPieDataset ds = new DefaultPieDataset();
    		ds.setValue("IBM", 2000);
    		ds.setValue("ORACLE", 3500);
    		ds.setValue("JBOSS", 1570);
    		ds.setValue("用友", 4400);
    		JFreeChart chart = ChartFactory.createPieChart3D(title, ds, true, false, false);
    		
    		//中文
    		chart.getTitle().setFont(new Font("宋体", Font.BOLD, 25));//标题字体
    		chart.getLegend().setItemFont(new Font("宋体", Font.PLAIN, 18));
    		
    		//绘图区
    		PiePlot plot = (PiePlot) chart.getPlot();
    		plot.setLabelFont(new Font("宋体", Font.PLAIN, 15));
    		
    		//背景
    		//chart.setBackgroundImage(ImageIO.read(new File("f:/sunset.jpg")));//图表区背景
    		//plot.setBackgroundImage(ImageIO.read(new File("f:/water.jpg")));
    		
    		//设置分裂效果
    		plot.setExplodePercent("IBM", 0.1f);
    		plot.setExplodePercent("JBOSS", 0.2f);
    		
    		//设置前景色透明度
    		plot.setForegroundAlpha(0.7f);
    		
    		//设置标签生成器
    		//{0}:公司名称
    		//{1}:销量
    		//{2}:百分比
    		//{3}:总量
    		//{4}:
    		plot.setLabelGenerator(new StandardPieSectionLabelGenerator("{0}({1}/{3}-{2})"));
    		ChartUtilities.saveChartAsJPEG(new File("f:\\pie.jpg"), chart, 800, 500);
    	}
    }

效果如下：

![Center 1][]

2，生成柱状图

package cn.itcast.jfreechart;
    
    import java.awt.Font;
    import java.io.File;
    
    import org.jfree.chart.ChartFactory;
    import org.jfree.chart.ChartUtilities;
    import org.jfree.chart.JFreeChart;
    import org.jfree.chart.plot.CategoryPlot;
    import org.jfree.chart.plot.PlotOrientation;
    import org.jfree.data.category.DefaultCategoryDataset;
    
    public class AppBar {
    	
    	public static void main(String[] args) throws Exception {
    		DefaultCategoryDataset ds = new DefaultCategoryDataset();
    		ds.addValue(2000, "IBM", "一季度");
    		ds.addValue(2300, "ORACLE", "一季度");
    		ds.addValue(2800, "JBOSS", "一季度");
    		ds.addValue(3300, "用友", "一季度");
    		
    		ds.addValue(4800, "IBM", "二季度");
    		ds.addValue(4300, "ORACLE", "二季度");
    		ds.addValue(3200, "JBOSS", "二季度");
    		ds.addValue(1800, "用友", "二季度");
    		
    		ds.addValue(1500, "IBM", "三季度");
    		ds.addValue(2600, "ORACLE", "三季度");
    		ds.addValue(3900, "JBOSS", "三季度");
    		ds.addValue(2100, "用友", "三季度");
    		
    		String title = "前三季度各大公司JEE AS销量统计" ;
    		JFreeChart chart = ChartFactory.createBarChart3D(title, "季度", "销量(单位:万台)", ds, PlotOrientation.VERTICAL, true, false, false);
    		
    		//中文
    		chart.getTitle().setFont(new Font("宋体", Font.BOLD, 25));//大标题
    		
    		//提示条
    		chart.getLegend().setItemFont(new Font("宋体", Font.BOLD, 15));
    		
    		CategoryPlot plot = (CategoryPlot) chart.getPlot();
    		//域轴字体
    		plot.getDomainAxis().setLabelFont(new Font("宋体", Font.BOLD, 18));
    		plot.getDomainAxis().setTickLabelFont(new Font("宋体", Font.PLAIN, 15));//小标签字体
    		
    		//range
    		plot.getRangeAxis().setLabelFont(new Font("宋体", Font.BOLD, 15));
    		
    		plot.setForegroundAlpha(0.6f);
    		
    		ChartUtilities.saveChartAsJPEG(new File("f:\\bar.jpg"), chart, 800, 500);
    	}
    }

效果如下：

![Center 2][]

3，生成折线图：

package cn.itcast.jfreechart;
    
    import java.awt.Font;
    import java.io.File;
    
    import org.jfree.chart.ChartFactory;
    import org.jfree.chart.ChartUtilities;
    import org.jfree.chart.JFreeChart;
    import org.jfree.chart.plot.CategoryPlot;
    import org.jfree.chart.plot.PlotOrientation;
    import org.jfree.data.category.DefaultCategoryDataset;
    
    public class AppLine {
    	
    	public static void main(String[] args) throws Exception {
    		DefaultCategoryDataset ds = new DefaultCategoryDataset();
    		ds.addValue(2000, "IBM", "一季度");
    		ds.addValue(2300, "ORACLE", "一季度");
    		ds.addValue(2800, "JBOSS", "一季度");
    		ds.addValue(3300, "用友", "一季度");
    		
    		ds.addValue(4800, "IBM", "二季度");
    		ds.addValue(4300, "ORACLE", "二季度");
    		ds.addValue(3200, "JBOSS", "二季度");
    		ds.addValue(1800, "用友", "二季度");
    		
    		ds.addValue(1500, "IBM", "三季度");
    		ds.addValue(2600, "ORACLE", "三季度");
    		ds.addValue(3900, "JBOSS", "三季度");
    		ds.addValue(2100, "用友", "三季度");
    		
    		String title = "前三季度各大公司JEE AS销量统计" ;
    		JFreeChart chart = ChartFactory.createLineChart(title, "季度", "销量(单位:万台)", ds, PlotOrientation.VERTICAL, true, false, false);
    		
    		//中文
    		chart.getTitle().setFont(new Font("宋体", Font.BOLD, 25));//大标题
    		
    		//提示条
    		chart.getLegend().setItemFont(new Font("宋体", Font.BOLD, 15));
    		
    		CategoryPlot plot = (CategoryPlot) chart.getPlot();
    		//域轴字体
    		plot.getDomainAxis().setLabelFont(new Font("宋体", Font.BOLD, 18));
    		plot.getDomainAxis().setTickLabelFont(new Font("宋体", Font.PLAIN, 15));//小标签字体
    		
    		//range
    		plot.getRangeAxis().setLabelFont(new Font("宋体", Font.BOLD, 15));
    		
    		plot.setForegroundAlpha(0.6f);
    		
    		ChartUtilities.saveChartAsJPEG(new File("f:\\line.jpg"), chart, 800, 500);
    	}
    }

效果如下：

![Center 3][]

示例工程：http://download.csdn.net/detail/u013614451/7344601

jfreeChart使用方法之一：（纯web环境，不采用框架，原理大致相当于将图片写到流中，然后页面直接在img 的src中引用）

1 ．添加工具类ChartUtil

public class ChartUtil { 
     public  static String generatePieChart(DefaultPieDataset dataset,String title,int width,int height,HttpSession session, PrintWriter pw) {    
      
    String filename = null;    
     try {    
     if (session != null)    
     {    
    ChartDeleter deleter = (ChartDeleter)session.getAttribute("JFreeChart_Deleter");    
     session.removeAttribute("JFreeChart_Deleter");    
     session.setAttribute("JFreeChart_Deleter", deleter);    
    }    
    JFreeChart chart = ChartFactory.createPieChart3D(    
    title,  // chart title    
    dataset, // data    
    true,  // include legend    
    true,    
    false );    
    //  Write the chart image to the temporary directory    
    ChartRenderingInfo info = new ChartRenderingInfo(new StandardEntityCollection());    
    //If the last parameter is null, the chart is a "one time"-chart and will be deleted after the first serving.    
    //If the last parameter is a session object, the chart remains until session time out.    
    filename = ServletUtilities.saveChartAsPNG(chart, width, height, info, session);    
    //  Write the image map to the PrintWriter    
     ChartUtilities.writeImageMap(pw, filename, info,true);    
     pw.flush();    
    } catch (Exception e) {    
     System.out.println("Exception - " + e.toString());    
     e.printStackTrace(System.out);    
     filename = "picture_error.png"; }    
    return filename;    
    }    
    }

}

2、在action里统计数据，设置好数据集dataset。传到页面   
  
       3、 在页面jsp里取出

DefaultPieDataset piedataset=(DefaultPieDataset)request.getAttribute("piedataset"); 
    String p = ChartUtil.generatePieChart(piedataset," 项目收支线图",500,300,null, new PrintWriter(out));    
    String p1 = request.getContextPath() + "/servlet/DisplayChart?filename=" + p;
    
    
    <td><img src="<%= p1 %>" width=500 height=300 border=0 usemap="#<%= p %>"></td>

4、在web.xml中添加

<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>/servlet/DisplayChart</url-pattern>  
    </servlet-mapping>

[Link 1]: http://baike.baidu.com/view/1323662.htm
[Link 2]: http://baike.baidu.com/view/916360.htm
[Link 3]: http://baike.baidu.com/view/1653.htm
[JPEG]: http://baike.baidu.com/view/191365.htm
[Center]: /images/20220824/3c91b444d3624b478ee49774ba8a3a6d.png
[Center 1]: /images/20220824/fde746db5e9d465dad8b8558565f026f.png
[Center 2]: /images/20220824/012d1f2bf9dc4ec29ee313dc5c50d5ad.png
[Center 3]: /images/20220824/af54985d43b94d0a93abb84ec9deea2d.png