在vue中post传参数为null如何处理

npm install axios --save

import axios from 'axios'
axios.defaults.headers.post['Content-Type'] = 'application/x-www-form-urlencoded';
axios.defaults.baseURL = 'http://localhost:7878/zkview';
Vue.prototype.$ajax = axios;

testGet: function () {
 this.$ajax({
  method: 'get',
  url: '/test/greeting',
  params: {
   firstName: 'Fred',
   lastName: 'Flintstone'
  }
 }).then(function (response) {
  console.log(response);
 }).catch(function (error) {
  console.log(error);
 });
},

testPost: function () {
    var params = new URLSearchParams();
    params.append('name', 'hello jdmc你好');
    params.append('id', '2');
    this.$ajax({
     method: 'post',
     url: '/test/greeting2',
     data:params
//     data: {id: '3', name: 'abc'}
    }).then(function (response) {
     console.log(response);
    }).catch(function (error) {
     console.log(error);
    })
   }

var params = new URLSearchParams();
params.append('name', 'hello jdmc你好');
params.append('id', '2');
data:params

public Student greeting2(int id,String name) {

data: {id: '3', name: 'abc'}

public Object greeting2(@RequestBody Object student) {