HarmonyOS 怎么解析本地文件json内容？

import resourceManager from '@ohos.resourceManager'; 
import buffer from '@ohos.buffer'; 
 
this.context.resourceManager.getRawFileContent("XXX.json", (error: BusinessError, value: Uint8Array) => { 
  if (error != null) { 
    console.error("error is " + error); 
  } else { 
    let rawFile = value; //Unit8Array 
    JSON.parse(buffer.from(rawFile.buffer).toString()) 
  }).catch((err:BusinessError)=>{ 
    console.log(`Invoke documentViewPicker.save to file failed, code is ${err.code}, message is ${err.message}`) 
  })

export class citydata { 
  id: string = '' 
  parentId: string = '' 
  text: string = '' 
  children?: citydata[] | undefined 
}