axios发送post请求springMVC接收不到参数的解决方法

//设置全局的axios.defaults.headers.post['Content-Type'] = 'application/x-www-form-urlencoded';var instance = axios.create({}) // 这样创建出来的 只需要：instance.defaults.headers.post['Content-Type'] = 'application/x-www-form-urlencoded';

var params = new URLSearchParams();params.append("username", _this.username);params.append("password", _this.password);axios.post("/service/login", paramsOfJson   ).then(function (response) {    console.log(response);   }).catch(function (error) {    console.log(error);   })

@PostMapping(value = "/login")public String testLogin(@RequestBody Map dataMap)