如何保存faultLogger ，有人知道吗？

import fs from '@ohos.file.fs'; 
import { BusinessError } from '@ohos.base'; 
import hilog from '@ohos.hilog'; 
import common from '@ohos.app.ability.common'; 
import AbilityConstant from '@ohos.app.ability.AbilityConstant'; 
import FaultLogger from '@ohos.faultLogger'; 
import preferences from '@ohos.data.preferences'; 
 
const TAG: string = 'testTag' 
 
export class LogUtils { 
  // import faultLogger from '@ohos.faultLogger' 
  static async queryAndUploadFaultLog(context: common.UIAbilityContext, launchParam: AbilityConstant.LaunchParam) { 
    if (launchParam.lastExitReason == AbilityConstant.LastExitReason.NORMAL) { 
      hilog.info(0x00000, TAG, '上次应用退出时未发生异常'); 
      return; 
    } 
    let value: Array<FaultLogger.FaultLogInfo> = await FaultLogger.query(FaultLogger.FaultType.NO_SPECIFIC) 
    hilog.info(0x00000, TAG, '报错日志:' + value.toString()); 
    if (value) { 
      let len = value.length 
      hilog.info(0x00000, TAG, '报错日志数量：' + len); 
      if (len === 0) { 
        return; 
      } 
      //取得实例 
      let preference: preferences.Preferences = await preferences.getPreferences(context, "STLiveness"); 
      // 查询上一次的处理的时间戳 
      let lastFaultHandleTime = preference.getSync('faultHandleTime', 0) 
      hilog.info(0x0000, TAG, "lastFaultHandleTime:" + lastFaultHandleTime); 
      // let innerContext = context; 
      for (let i = 0; i < len; i++) { 
        let timestamp = value[i].timestamp 
        hilog.info(0x00000, TAG, '日志文件名称#' + timestamp); 
        if (lastFaultHandleTime >= timestamp) { 
          hilog.error(0x00000, TAG, "Maple No New Logs."); 
          return; 
        } 
        // 将日志保存到应用沙箱的目录 保存文件名为 时间戳.log 
        await LogUtils.save(value[i].fullLog, context.filesDir + "/crash", timestamp + ".log") 
        await preference.put("faultHandleTime", timestamp); 
        await preference.flush() 
      } 
    } 
  } 
  static async save(buffer: ArrayBuffer | string, destFilePath: string, name: string): Promise<string> { 
    await LogUtils.mkdir(destFilePath); 
    hilog.info(0x00000, TAG, '写入日志的内容为：' + buffer); 
    hilog.info(0x00000, TAG, '被写入的日志文件路径为：' + destFilePath); 
    if (buffer) { 
      try { 
        let file = fs.openSync(destFilePath + "/" + name, fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE); 
        fs.writeSync(file.fd, buffer); 
        fs.closeSync(file) 
      } catch (error) { 
        let e: BusinessError = error as BusinessError; 
        hilog.info(0x0000, TAG, "FileUtils:save:::" + e.message); 
      } 
    } 
    return destFilePath; 
  } 
 
  static async mkdir(destFilePath: string) { 
    hilog.info(0x00000, TAG, '开始创建目录：' + destFilePath); 
    if (fs.accessSync(destFilePath)) { 
      hilog.info(0x00000, TAG, '目录已经存在，无需创建'); 
      return 
    } 
    await fs.mkdir(destFilePath) 
    hilog.info(0x00000, TAG, '创建完成'); 
  } 
}