415报错

报错 Content type ‘application/x-www-form-urlencoded;charset=UTF-8’ not supported
ajax要设置请求头类型，类似以下方式：

  putJSON: function(url, param) {
    let jsonParam = JSON.stringify(param)
    let headers = {}
    headers['Content-Type'] = 'application/json'
    return axios.put(url, jsonParam, { headers: headers }).then(res => {
      return res
    })
  },