我导入源代码，为什么eclipse报告这么多错误？我该怎么办？

Question

导入org.jfree。*会出错？我从未导入过此软件包，对此一无所知，是否需要其他配置？

import java.util.*;

import java.awt.Color;
import java.awt.BasicStroke;

//the area of code below is informed error

import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.ui.ApplicationFrame;
import org.jfree.data.xy.XYDataset;
import org.jfree.data.xy.XYSeries;

import org.jfree.chart.plot.XYPlot;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.data.xy.XYSeriesCollection;
import org.jfree.chart.renderer.xy.XYLineAndShapeRenderer;
public class Drive extends ApplicationFrame{
                     .....
}