网络资源下载包rawfile目录，如何实现？

onWindowStageCreate(windowStage: window.WindowStage): void { 
  let filesDir = this.context.filesDir 
 
  try { 
  request.downloadFile(this.context, { 
  url: 'https://xxxx/xxxx.txt', 
  filePath: filesDir + '/xxxx.txt' 
}).then((downloadTask: request.DownloadTask) => { 
  downloadTask.on('complete', () => { 
    console.info('download complete'); 
    let file = fs.openSync(filesDir + '/xxxx.txt', fs.OpenMode.READ_WRITE); 
    let arrayBuffer = new ArrayBuffer(1024); 
    let readLen = fs.readSync(file.fd, arrayBuffer); 
    let buf = buffer.from(arrayBuffer, 0, readLen); 
    console.info(`The content of file: ${buf.toString()}`); 
    fs.closeSync(file); 
  }) 
}).catch((err: BusinessError) => { 
  console.error(`Invoke downloadTask failed, code is ${err.code}, message is ${err.message}`); 
}); 
} catch (error) { 
  let err: BusinessError = error as BusinessError; 
  console.error(`Invoke downloadFile failed, code is ${err.code}, message is ${err.message}`); 
} 
// Main window is created, set main page for this ability 
hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onWindowStageCreate'); 
 
windowStage.loadContent('pages/Index', (err) => { 
  if (err.code) { 
    hilog.error(0x0000, 'testTag', 'Failed to load the content. Cause: %{public}s', JSON.stringify(err) ?? ''); 
    return; 
  } 
  hilog.info(0x0000, 'testTag', 'Succeeded in loading the content.'); 
 
}); 
}