IDEA多线程文件下载插件开发的步骤详解

  cn.silently9527.fast-download-idea-plugin  
  FastDownloadPlugin 
  Silently9527
  
  

  
  

  
    
  

  
    
  

public class FastDownloadAction extends AnAction {
  @Override
  public void actionPerformed(AnActionEvent e) {

}
}

@Nullable
@Override
protected JComponent createCenterPanel() {
  Box verticalBox = Box.createVerticalBox();
  verticalBox.add(createUrlBox());
  verticalBox.add(Box.createVerticalStrut(10));
  verticalBox.add(createFileDirJPanel());
  verticalBox.add(Box.createVerticalStrut(10));
  verticalBox.add(createThreadNumJPanel());
  return verticalBox;
}

@Nullable
@Override
protected ValidationInfo doValidate() {
  if (StringUtils.isBlank(downloadUrlField.getText())) {
    return new ValidationInfo("文件下载地址必填");
  }
  if (StringUtils.isBlank(fileDirField.getText())) {
    return new ValidationInfo("文件保存目录必填");
  }
  if (StringUtils.isBlank(threadNumField.getText())) {
    return new ValidationInfo("下载线程数必填");
  }
  return null;
}

DownloadDialog downloadDialog = new DownloadDialog();
if (downloadDialog.showAndGet()) {
  // 用户点击OK之后进入到这里
}

CompletableFuture.runAsync(() -> {
  try {
    Downloader downloader = new MultiThreadFileDownloader(threadNum, downloadProgressPrinter);
    downloader.download(downloadURL, downloadDir);
  } catch (IOException e) {
    throw new RuntimeException(e);
  }
})

//使用SDK开启一个后台任务线程
ProgressManager.getInstance().run(new Task.Backgroundable(project, "File Downloading") {
  private long tmpAlreadyDownloadLength; //当前已下载字节数
  private long speed; //每秒下载速度

  public void run(@NotNull ProgressIndicator progressIndicator) {
    // start your process
    while (true) {
      long alreadyDownloadLength = downloadProgressPrinter.getAlreadyDownloadLength();
      long cOntentLength= downloadProgressPrinter.getContentLength();
      if (alreadyDownloadLength != 0 && alreadyDownloadLength >= contentLength) {
        // 下载已完成，进度条显示100%
        progressIndicator.setFraction(1.0);
        progressIndicator.setText("finished");
        break;
      }
      setProgressIndicator(progressIndicator, contentLength, alreadyDownloadLength);
      sleep();
    }
  }

  private void setProgressIndicator(ProgressIndicator progressIndicator, long contentLength,
                   long alreadyDownloadLength) {
    if (alreadyDownloadLength == 0 || cOntentLength== 0) {
      return;
    }
    speed = alreadyDownloadLength - tmpAlreadyDownloadLength;
    tmpAlreadyDownloadLength = alreadyDownloadLength;

    double value = (double) alreadyDownloadLength / (double) contentLength;

    double fraction = Double.parseDouble(String.format("%.2f", value));
    progressIndicator.setFraction(fraction);
    String text = "already download " + fraction * 100 + "% ,speed: " + (speed / 1000) + "KB";
    progressIndicator.setText(text); //进度条显示已下载百分比，下载速度
  }
});