public class xyArea{
public static void main(String arg[]){
XYSeries series = new XYSeries("Average Weight");
series.add(20.0, 20.0);
series.add(40.0, 25.0);
series.add(55.0, 50.0);
series.add(70.0, 65.0);
XYDataset xyDataset = new XYSeriesCollection(series);
JFreeChart chart = ChartFactory.createAreaChart
("XY Chart using JFreeChart", "Age", "Weight",
(CategoryDataset) xyDataset, PlotOrientation.VERTICAL, true,
true, false);
ChartFrame frame1=new ChartFrame("XYArea Chart",chart);
frame1.setVisible(true);
frame1.setSize(300,300);
}
}
我写了这段代码,但出现以下错误,请指导我:
线程“主”中的异常java.lang.ClassCastException:org.jfree.data.xy.XYSeriesCollection无法转换为org.jfree.data.CategoryDataset
在xyArea.main(xyArea.java:21)
最佳答案
好吧,您不能转换为CategoryDataset
,因为XYSeriesCollection
不是CategoryDataset
。
看来您需要.createXYAreaChart(..)
(而不是.createAreaChart(..)
)