JFreeChart之堆叠柱形图(StackedBar)

extendedstackedbarrenderer.setBaseItemLabelGenerator(new StandardCategoryItemLabelGenerator("{3}", 

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2 NumberFormat.getPercentInstance(), new DecimalFormat("#0.0%"))); 

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3 

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但是柱体的返回的值是10.1/50.1=20.2%,40.1/50.1=79.8%

这不符合预期目标，所以就去看了一下源码，在StandardCategoryItemLabelGenerator的父类AbstractCategoryItemLabelGenerator中发现有createItemArray这么一个方法：

可以发现柱体的标签值应该是由这个方法进行返回的，因此自己就对StandardCategoryItemLabelGenerator进行了继承，并重写了这个方法。
在ExtendedStandardCategoryItemLabelGeneratory中增加了isPercent作为标签值是显示百分比还是仅仅格式化的判断参数，并重写了createItemArray这个方法。

此时得到的效果如图：

然而，柱体的总值还是没有格式化。再看了一下ExtendedStackedBarRenderer这个类的代码，找到了totalFormat这个属性，将其值赋为new DecimalFormat("#0.0%")。测试：

基本是想要的最终结果,下面是测试代码

1. 1 <dependency> 

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2. 2 <groupId>jfree</groupId> 

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3. 3 <artifactId>jfreechart</artifactId> 

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4. 4 <version>1.0.13</version> 

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5. 5 </dependency> 

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ExtendedStackedBarRenderer

1. 1package com.springapp.jfreechar; 

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2. 2 

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3. 3import java.awt.Color; 

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4. 4import java.awt.Font; 

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5. 5import java.awt.Graphics2D; 

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6. 6import java.awt.geom.Rectangle2D; 

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7. 7import java.text.DecimalFormat; 

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8. 8import java.text.NumberFormat; 

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9. 9 

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10. 10import org.jfree.chart.axis.CategoryAxis; 

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11. 11import org.jfree.chart.axis.ValueAxis; 

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12. 12import org.jfree.chart.entity.CategoryItemEntity; 

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13. 13import org.jfree.chart.entity.EntityCollection; 

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14. 14import org.jfree.chart.labels.CategoryToolTipGenerator; 

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15. 15import org.jfree.chart.plot.CategoryPlot; 

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16. 16import org.jfree.chart.plot.PlotOrientation; 

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17. 17import org.jfree.chart.renderer.category.CategoryItemRendererState; 

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18. 18import org.jfree.chart.renderer.category.StackedBarRenderer; 

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19. 19import org.jfree.data.category.CategoryDataset; 

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20. 20import org.jfree.text.TextUtilities; 

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21. 21import org.jfree.ui.TextAnchor; 

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22. 22 

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23. 23public class ExtendedStackedBarRenderer extends StackedBarRenderer { 

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24. 24 

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25. 25 private static final long serialVersionUID = 1L; 

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26. 26 private boolean showPositiveTotal; 

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27. 27 private boolean showNegativeTotal; 

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28. 28 private Font totalLabelFont; 

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29. 29 private NumberFormat totalFormatter; 

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30. 30 public ExtendedStackedBarRenderer() { 

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31. 31 showPositiveTotal = true; 

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32. 32 showNegativeTotal = true; 

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33. 33 totalLabelFont = new Font("SansSerif", 1, 12); 

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34. 34 totalFormatter = new DecimalFormat("#0.0%"); 

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35. 35 } 

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36. 36 

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37. 37 /** 

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38. 38 * StackedBarRenderer 没有这个构造方法的，传入一个NumberFormat类，可以自定义实现每个柱体值显示格式 

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39. 39 * @param totalFormatter 

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40. 40 */ 

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41. 41 public ExtendedStackedBarRenderer(NumberFormat totalFormatter) { 

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42. 42 showPositiveTotal = true; 

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43. 43 showNegativeTotal = true; 

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44. 44 totalLabelFont = new Font("SansSerif", 1, 12); 

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45. 45 this.totalFormatter = totalFormatter; 

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46. 46 } 

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47. 47 

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48. 48 public NumberFormat getTotalFormatter() { 

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49. 49 return totalFormatter; 

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50. 50 } 

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51. 51 

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52. 52 public void setTotalFormatter(NumberFormat numberformat) { 

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53. 53 if (numberformat == null) { 

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54. 54 throw new IllegalArgumentException("Null format not permitted."); 

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55. 55 } else { 

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56. 56 totalFormatter = numberformat; 

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57. 57 return; 

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58. 58 } 

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59. 59 } 

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60. 60 

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61. 61 public void drawItem(Graphics2D graphics2d, CategoryItemRendererState categoryitemrendererstate, Rectangle2D rectangle2d, CategoryPlot categoryplot, CategoryAxis categoryaxis, 

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62. 62 ValueAxis valueaxis, CategoryDataset categorydataset, int i, int j, int k) { 

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63. 63 Number number = categorydataset.getValue(i, j); 

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64. 64 if (number ==