jFreeChart利用CategoryDatase,ChartFactory.createBarChart生成的柱状图

Createjfreechartbar 代码  收藏代码
  1. package com.potevio.rnd;  
  2.   
  3. import java.io.File;  
  4. import java.io.FileNotFoundException;  
  5. import java.io.FileOutputStream;  
  6. import java.io.IOException;  
  7.   
  8. import org.jfree.chart.ChartFactory;  
  9. import org.jfree.chart.ChartUtilities;  
  10. import org.jfree.chart.JFreeChart;  
  11. import org.jfree.chart.plot.CategoryPlot;  
  12. import org.jfree.chart.plot.PlotOrientation;  
  13. import org.jfree.data.category.CategoryDataset;  
  14. import org.jfree.data.general.DatasetUtilities;  
  15.   
  16. public class CreateJFreeChartBar {     
  17.     
  18.     /**    
  19.      * 创建JFreeChart Bar Chart（柱状图）    
  20.      */    
  21.     public static void main(String[] args) {     
  22.         //步骤1：创建CategoryDataset对象（准备数据）     
  23.         CategoryDataset dataset = createDataset();     
  24.         //步骤2：根据Dataset 生成JFreeChart对象，以及做相应的设置     
  25.         JFreeChart freeChart = createChart(dataset);     
  26.         //步骤3：将JFreeChart对象输出到文件，Servlet输出流等     
  27.         saveAsFile(freeChart, "F:\jfreechart\bar.png", 500, 400);     
  28.     }     
  29.          
  30.     //保存为文件     
  31.     public static void saveAsFile(JFreeChart chart, String outputPath, int weight, int height) {     
  32.         FileOutputStream out = null;     
  33.         try {     
  34.             File outFile = new File(outputPath);     
  35.             if (!outFile.getParentFile().exists()) {     
  36.                 outFile.getParentFile().mkdirs();     
  37.             }     
  38.             out = new FileOutputStream(outputPath);     
  39.             //保存为PNG文件     
  40.             ChartUtilities.writeChartAsPNG(out, chart, weight, height);     
  41.             //保存为JPEG文件     
  42.             //ChartUtilities.writeChartAsJPEG(out, chart, weight, height);     
  43.             out.flush();     
  44.         } catch (FileNotFoundException e) {     
  45.             e.printStackTrace();     
  46.         } catch (IOException e) {     
  47.             e.printStackTrace();     
  48.         } finally {     
  49.             if (out != null) {     
  50.                 try {     
  51.                     out.close();     
  52.                 } catch (IOException e) {     
  53.                     //do nothing     
  54.                 }     
  55.             }     
  56.         }     
  57.     }     
  58.     
  59.     //根据CategoryDataset生成JFreeChart对象     
  60.     public static JFreeChart createChart(CategoryDataset categoryDataset) {     
  61.         JFreeChart jfreechart = ChartFactory.createBarChart("Bar Chart Demo",    //标题     
  62.                 "产品",    //categoryAxisLabel （category轴，横轴，X轴的标签）     
  63.                 "数量",    //valueAxisLabel（value轴，纵轴，Y轴的标签）     
  64.                 categoryDataset, // dataset     
  65.                 PlotOrientation.VERTICAL,     
  66.                 true, // legend     
  67.                 false, // tooltips     
  68.                 false); // URLs     
  69.              
  70.         //以下的设置可以由用户定制，也可以省略     
  71.         CategoryPlot  plot = (CategoryPlot) jfreechart.getPlot();     
  72.         //背景色　透明度     
  73.         plot.setBackgroundAlpha(0.5f);     
  74.         //前景色　透明度     
  75.         plot.setForegroundAlpha(0.5f);     
  76.         //其它设置可以参考 CategoryPlot     
  77.              
  78.         return jfreechart;     
  79.     }     
  80.     
  81.     /**    
  82.      * 创建CategoryDataset对象    
  83.      *     
  84.      */    
  85.     public static CategoryDataset createDataset() {     
  86.              
  87.         String []rowKeys = {"One", "Two", "Three"};     
  88.         String []colKeys = {"1987", "1997", "2007"};     
  89.              
  90.         double [][] data = {     
  91.                 {50, 20, 30},     
  92.                 {20, 10D, 40D},     
  93.                 {40, 30.0008D, 38.24D},     
  94.         };     
  95.              
  96.         //也可以使用以下代码     
  97.         //DefaultCategoryDataset categoryDataset = new DefaultCategoryDataset();     
  98.         //categoryDataset.addValue(10, "rowKey", "colKey");     
  99.              
  100.         return DatasetUtilities.createCategoryDataset(rowKeys, colKeys, data);             
  101.     }     
  102.     
  103. }  

运行效果图：

 

 

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原文地址：https://www.cnblogs.com/jpfss/p/7403648.html