微信小程序request出现400的问题解决办法

wx.request({
  url : "https://api.douban.com/v2/movie/top250",
  data: {},
  header:{
    "Content-Type":"application/json"
  },
  success: function(res) {
    console.log(res.data);
    var data = res.data;
    currentPage.setData({
      list : data.subjects
    })
  },
});  

header:{
  "Content-Type":"json"
},