HarmonyOS request downloadfile在一台模拟器设备上测试失败

SendRequest 148: failed, handle:0 error:3 desc:*.ISystemAbilityManager 
[request_manager.cpp LoadServerSuccess 408] load download server success 
[request_manager.cpp OnRemoteDied 347] RequestSaDeathRecipient on remote systemAbility died.

getNetPic(context: Context, url: string,fileName: string, 
success: (filePath : string) => void) { 
  hilog.error(0x0000, 'ch_test', 'context >>> ' + context.toString()); 
  let filesDir = context.filesDir; 
  let temFileName = Date.now() + fileName 
  let temFile = filesDir + '/' + temFileName 
  hilog.error(0x0000, 'ch_test', 'temFile >>> ' + temFile); 
  try { 
    // 需要手动将 url 替换为真实服务器的 HTTP 协议地址 
    request.downloadFile(context, { 
      url: url, 
      filePath: temFile 
    }, (err: BusinessError, data: request.DownloadTask) => { 
      if (err) { 
        console.error(`Failed to request the download. Code: ${err.code}, message: ${err.message}`); 
        return; 
      } 
      let downloadTask: request.DownloadTask = data; 
      hilog.error(0x0000, 'ch_test', 'download complete >>> ' + downloadTask.toString()); 
      downloadTask.on('complete', () => { 
        success(temFile) 
      }) 
    }); 
  } catch (err) { 
    console.error(`Failed to request the download. err: ${JSON.stringify(err)}`); 
  } 
}