//Open:
JFileChooser fileChooser = new JFileChooser();
if (fileChooser.showOpenDialog(modalToComponent or null) == JFileChooser.APPROVE_OPTION) {
File file = fileChooser.getSelectedFile();
// load from file
}
//Save:
JFileChooser fileChooser = new JFileChooser();
if (fileChooser.showSaveDialog(modalToComponent or null) == JFileChooser.APPROVE_OPTION) {
File file = fileChooser.getSelectedFile();
// save to file
}