JFreeChart將百分比添加到JSP中的PieChart中

Question

這是我在JSP中創建PieChart的代碼。

Connection conn = DBConnection.getConnection(); 

String strQuery = "SELECT keyword,count(*) from paper_keywords group by keyword"; 
PreparedStatement preparedStatement = conn.prepareStatement(strQuery); 
ResultSet rs = preparedStatement.executeQuery(); 

DefaultPieDataset pieDataset = new DefaultPieDataset(); 
while(rs.next()) 
{ 
    pieDataset.setValue(rs.getString(1),rs.getInt(2)); 
} 
rs.close(); 
preparedStatement.close(); 

JFreeChart chart = ChartFactory.createPieChart ("Popular Keywords", pieDataset, true,true,true); 

try { 
    final ChartRenderingInfo info = new ChartRenderingInfo (new StandardEntityCollection()); 


String test = getServletContext().getRealPath("/"); 
final File file1 = new File(test+"chart/areachart.png"); 

ChartUtilities.saveChartAsPNG(file1, chart, 550, 400, info); 
} 
catch (Exception e) { 
out.println(e); 
} 

我稍後會在JSP頁面中使用它：

<IMG SRC="../chart/areachart.png" > 

我怎樣才能在圖例添加比例是多少？謝謝！

Answer 1

StandardPieSectionLabelGenerator可以做到這一點。

PiePlot plot = (PiePlot) chart.getPlot(); 
plot.setLegendLabelGenerator(
    new StandardPieSectionLabelGenerator("{0} {1} {2}")); 

Answer 2

步驟1：http://www.java2s.com/Code/Jar/j/Downloadjfreechartjar.htm

第二步首先下載的JFreeChart：包括在構建路徑的jar文件

3步：添加以下代碼

PiePlot plot2 = (PiePlot) chart.getPlot(); 
     plot2.setLabelGenerator(new StandardPieItemLabelGenerator(
       "{0} ({2})", NumberFormat.getNumberInstance(), NumberFormat.getPercentInstance() 
      ));