JFreeChart设置背景图片

freechart= ChartFactory.createTimeSeriesChart("图", "", "",dataset, true, false, false);

try {

        // 设置背景图片
         Image image = ImageIO.read(new   File("D://car.gif"));              
         chart.setBackgroundImage(image);
        } catch (IOException e) {
         e.printStackTrace();
        } 

    XYPlot plot = chart.getXYPlot();
  
    plot.setBackgroundPaint(null);// 设置背景颜色,这条语句一定要设置为null