HarmonyOS axios请求问题

demo如下：

postMethod() {
  let postUrl: string = 'http://localhost:8848/checkParams';

  let simpleForm: rcp.FormFields = {};
  simpleForm['txnBody'] = "XXX";
  simpleForm['txnHeaderInfo'] = "xxx"

  let rcpSession: rcp.Session = rcp.createSession();
  let result = rcpSession.post(postUrl, simpleForm)
  result.then((res) => {
    console.log('res： ' + JSON.stringify(res))
    if (res.body) {
      let re = this.ArrayBuffer2String(res.body)
      console.log('re： ' + re)
    }
  }).catch((err: BusinessError) => {
    console.error(`err: err code is ${err.code}, err message is ${err.message}`);
  });
}

ArrayBuffer2String(buf: ArrayBuffer) {
  const decoder = util.TextDecoder.create("utf-8");
  const str = decoder.decodeWithStream(new Uint8Array(buf));
  return str;
}

simpleForm支持动态增减入参对象。请求到后台后，Java侧可以使用IOUtils.toString(request.getReader())解析出响应参数