HarmonyOS json数据和对象互转时问题

可以通过new对象来排除多余字段，参考代码如下：

import { JSON } from '@kit.ArkTS';

@Entry
@Component
struct Index3 {
  @State message: string = 'Hello World';
  aboutToAppear(): void {
    let src = `{
"id":936,
"schoolName":"广州校",
"schoolDesc":"gz",
"defaultFlag":0,
"companyId":4,
"indexDomain":"",
"companyIdentification":"",
"xzqhCode":"440000",
"provinceName":"广东省"
}`

    let param = JSON.parse(src) as SchoolBean
    let param2 = new SchoolBean(param)
    AlertDialog.show({ message: `${JSON.stringify(param2)}` })
  }

  build() {
    RelativeContainer() {
      Text(this.message)
        .id('Index3HelloWorld')
        .fontSize(50)
        .fontWeight(FontWeight.Bold)
        .alignRules({
          center: { anchor: '__container__', align: VerticalAlign.Center },
          middle: { anchor: '__container__', align: HorizontalAlign.Center }
        })
    }
    .height('100%')
    .width('100%')
  }
}

export class SchoolBean {
  constructor(param: SchoolBean) {
    this.id = param.id;
    this.schoolName = param.schoolName;
    this.provinceName = param.provinceName;
    this.xzqhCode = param.xzqhCode;
  }

  id: number = 0
  schoolName: string = ""
  provinceName: string = ""
  xzqhCode: string = ""
}