JFileChooser and filechooser.FileFilter

import javax.swing.JFileChooser;
import javax.swing.filechooser.FileFilter;

class FileChoose{
    /*
     * the class for file save and file choose
     */
    private JFileChooser fc=new JFileChooser();
    public FileChoose(){
        cfFileFilter filter = new cfFileFilter();
        fc.addChoosableFileFilter(filter);
        fc.setFileFilter(filter);
    }

    public void save_conf(String confContent){
        /*
         * show save dialog
         */
        fc.setDialogTitle("Save lab conf file");
        int rc = fc.showSaveDialog(fc);
        if(rc==JFileChooser.APPROVE_OPTION){
            File file = fc.getSelectedFile();
            //System.out.println(file.getPath());

            save_data(confContent,file.getPath());
        }

    }
    private void save_data(String confContent,String path){
        /*
         * save info to cf file
         */
        try{
        FileWriter f = new FileWriter(path);
        f.write(confContent);
        f.close();
        }catch (IOException e) {
            e.printStackTrace();
        }

    }


    public List<String> select_conf(){
        /*
         * show file choosen dialog
         */
        fc.setDialogTitle("Select lab conf file");
        int rc = fc.showOpenDialog(fc);
        if(rc==JFileChooser.APPROVE_OPTION){
            File file = fc.getSelectedFile();
            //System.out.println(file.getPath());

            List<String> datas = get_data(file.getPath());
            return datas;
        }
        return null;

    }

    private List<String> get_data(String path){
        /*
         * get lab info from cf file
         */
        List<String> datas = new ArrayList<String>();
        try{
            BufferedReader f = new BufferedReader(new FileReader(path));
            String line = null;
            while((line = f.readLine()) !=null){
                datas.add(line);
            }
            f.close();
        }catch (IOException e) {
            e.printStackTrace();
        }

        return datas;
    }

}

class cfFileFilter extends FileFilter {
    /*
     * (non-Javadoc)
     * @see javax.swing.filechooser.FileFilter#accept(java.io.File)
     * the class extends from FileFilter to filter files except .cf file and directory
     * show .cf file and directory only on file choosen dialog
     */
    public boolean accept(File file) {
        String name = file.getName();
        if(file.isDirectory()){
            return true;
        }

        return name.toLowerCase().endsWith(".cf");
    }

    @Override
    public String getDescription() {
        // TODO Auto-generated method stub

        return "*.cf";
    }
}

The class extends FileFilter must overwrite two methods ,
one is public boolean accept(File file)
the other is public String getDescription()