我正在使用JFreeChart绘制图形。代码是packagecom.daya;importjava.awt.Color;importjava.io.BufferedReader;importjava.io.DataInputStream;importjava.io.FileInputStream;importjava.io.InputStreamReader;importorg.jfree.chart.ChartFactory;importorg.jfree.chart.ChartPanel;importorg.jfree.chart.JFreeChart;importorg.jfre