这个可编辑的最小代码片段示例如何使用JFreeChart作为绘图API,以便显示absoulte值和百分比?
我无法从互联网上的任何代码段或JFreechart手册本身中提取此信息.代码段生成一个仅显示百分比的饼图.在我的情况下绝对值也很重要,所以我需要在百分比下显示它们.
这是代码:(注意它没有导入)
public class MyMinimalPieChartExample {
public static void main(String[] args) {
DefaultPieDataset dataset = new DefaultPieDataset();
dataset.setValue("some data 1",99);
dataset.setValue("some data 2", 77);
//third adaption
JFreeChart someChart = ChartFactory.createPieChart(
"some chart header", dataset,
true, true, false);
PiePlot illegalLegalRestPiePlot4 = (PiePlot) someChart.getPlot();
illegalLegalRestPiePlot4.setSectionPaint("some data 1", new Color(0, 255, 0));
illegalLegalRestPiePlot4.setSectionPaint("some data 2",
new Color(255, 0, 0));
PiePlot plot4 = (PiePlot) someChart.getPlot();
plot4.setExplodePercent("some data 1", 0.4);
plot4.setSimpleLabels(true);
PieSectionLabelGenerator generator = new StandardPieSectionLabelGenerator(
"{0} = {2}", new DecimalFormat("0"), new DecimalFormat("0.00%"));
plot4.setLabelGenerator(generator);
try {
ChartUtilities.saveChartAsJPEG(new File("C:/myMinimalPieChartExample.jpeg"),
someChart, 1200, 1000);
} catch (Exception e) {
System.err.println("couldn't write chart");
}
}
}
解决方法:
使用MessageFormat符号{1}作为绝对节值.
有关详情,请参见StandardPieSectionLabelGenerator
.
public class MyMinimalPieChartExample {
private static final String KEY1 = "Datum 1";
public static final String KEY2 = "Datum 2";
public static void main(String[] args) {
DefaultPieDataset dataset = new DefaultPieDataset();
dataset.setValue(KEY1, 99);
dataset.setValue(KEY2, 77);
JFreeChart someChart = ChartFactory.createPieChart(
"Header", dataset, true, true, false);
PiePlot plot = (PiePlot) someChart.getPlot();
plot.setSectionPaint(KEY1, Color.green);
plot.setSectionPaint(KEY2, Color.red);
plot.setExplodePercent(KEY1, 0.10);
plot.setSimpleLabels(true);
PieSectionLabelGenerator gen = new StandardPieSectionLabelGenerator(
"{0}: {1} ({2})", new DecimalFormat("0"), new DecimalFormat("0%"));
plot.setLabelGenerator(gen);
JFrame f = new JFrame("Test");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.add(new ChartPanel(someChart) {
@Override
public Dimension getPreferredSize() {
return new Dimension(400, 300);
}
});
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
}