java下载时如何解决JavaFXProgressIndicator重绘问题？

Question

我正在用这个循环从ftp客户端下载文件

private void download(String date){
    try {
        FTPFile ftpFile = client.mlistFile(filename());
        long ftpFileSize = ftpFile.getSize();
        frame.setMaximumProgress((int) ftpFileSize);
        File downloadFile = new File(folder + filename());
        OutputStream outputStream2 = new BufferedOutputStream(new FileOutputStream(downloadFile));
        InputStream inputStream = client.retrieveFileStream(fileName);
        byte[] bytesArray = new byte[4096];
        int bytesRead = -1;
        int bytes = 0;
        while ((bytesRead = inputStream.read(bytesArray)) != -1){
            outputStream2.write(bytesArray, 0, bytesRead);
            bytes += bytesRead;
        }
        if (client.completePendingCommand()){
            outputStream2.close();
            inputStream.close();
        } else{
            JOptionPane.showMessageDialog(null, "Downloading error.");
        }
    } catch (IOException e) {
        if(e instanceof FTPConnectionClosedException){
            reconnect();
        }
    }
}

前进指示器仍然在一个位置上。 方法setProgress成功启动该进度

public void setProgress(double value){
    System.out.println(value);
    progress.setProgress(value);
}

Answer 1

只需按原意使用Task Class，无需重新发明轮子

public class DownloadTask extends Task<Void> {
  public Void call() {
    while ((bytesRead = inputStream.read(bytesArray)) != -1){
      outputStream2.write(bytesArray, 0, bytesRead);
      bytes += bytesRead;
      updateProgress(bytes, ftpFileSize);
    }
  }
}

并将{}的{}绑定到{}的{}上

有关如何绑定这两个属性的示例：

ProgressIndicator progress = new ProgressIndicator();
DownloadTask task = new DownloadTask();
progress.progressProperty().bind(task.progressProperty());
new Thread(task).start();