如何在PNG图像中保存JFreeChart的图形?

Question

将我收到的图形以图片的形式保存在计算机上的文件夹中时出现问题。在我看来，问题出在图片中的保存方法上，但我不知道如何解决问题。我在代码中标记了问题区域(saveImage(，希望得到您的帮助(

//create Graph
XYSeriesCollection seriesCollection1 = new XYSeriesCollection(series1);
chart1 = ChartFactory.createXYLineChart("Зависимость скорости полета от t",
"Время, с", "Скорость полета, км/ч", seriesCollection1, PlotOrientation.VERTICAL, false, true, false);
chartPanel1 = new ChartPanel(chart1);
chartPanel1.setPreferredSize(new Dimension(1300, 480));
panel.add(chartPanel1);
//saving method in picture
public void saveImage(File file) {
Rectangle rec = chartPanel1.getBounds();
BufferedImage img = new BufferedImage(rec.width, rec.height, BufferedImage.TYPE_INT_ARGB);
print(img.getGraphics()); // I think problem here.
try {
ImageIO.write(img, "png", file);
JOptionPane.showMessageDialog(null, "Данное изображение сохранено", "", JOptionPane.INFORMATION_MESSAGE);
} catch (IOException ex) {
JOptionPane.showMessageDialog(null, "Ошибка сохранения", "", JOptionPane.ERROR_MESSAGE);
}
}
//listener
saveImage.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
if (e.getSource() == saveImage) {
JFileChooser fc = new JFileChooser();
int op = fc.showSaveDialog(OpenFIle.this);
if (op == JFileChooser.APPROVE_OPTION){
String filename = fc.getSelectedFile().getName();
String path = fc.getSelectedFile().getParentFile().getPath();
int len = filename.length();
String ext = "";
String file = "";
if (len > 4){
ext = filename.substring(len - 4, len);
}
if (ext.equals(".png")){
file = path + "\" + filename;
}else {
file = path + "\" + filename + ".png";
}
saveImage(new File(file));
}
}
}
});
}

Answer 1

问题以这种方式解决

public void saveImage(File file) {
Rectangle rec = chartPanel1.getBounds();
BufferedImage img = new BufferedImage(rec.width, rec.height, BufferedImage.TYPE_INT_ARGB);
Graphics g = img.getGraphics();
chartPanel1.paint(g);
try {
ImageIO.write(img, "png", file);
JOptionPane.showMessageDialog(null, "Данное изображение сохранено", "", JOptionPane.INFORMATION_MESSAGE);
} catch (IOException ex) {
ex.printStackTrace();
}
}