HarmonyOS如何进行数据文件存储

import { Context } from '@ohos.abilityAccessCtrl'; 
import buffer from '@ohos.buffer'; 
@Entry 
@Component 
struct Index { 
  private context:Context = getContext(this) ; 
  private str:string = '' 
  getRawFile(): ESObject{ 
    //调用getRawFileContent接口获取json文件内容，并读为string 
    getContext(this).resourceManager.getRawFileContent("data.json",(err,data)=>{ 
      try { 
        this.str = buffer.from(data.buffer).toString(); 
        console.info(JSON.stringify(this.str)) 
      }catch (e){ 
        console.info(JSON.stringify(e)) 
      } 
    }) 
    //也可以调用getRawFileContentSync接口获取json文件内容，并读为string 
    try { 
      let data: Uint8Array= this.context.resourceManager.getRawFileContentSync("data.json"); 
      this.str = buffer.from(data.buffer).toString(); 
    } catch (e) { 
      console.info(JSON.stringify(e)) 
    } 
    // string转为ESObject 
    let obj:ESObject = JSON.parse(this.str) 
    return obj 
  } 
  build() { 
    Column() { 
      Button("get") 
        .onClick(() => { 
          this.getRawFile() 
        }) 
    }.width('100%') 
  } 
}