title: node jquery ajax servie side can not get data
body: <p>I'm a chinese,so my english is bad,and I give two pitcures to show my question
  <a href="https://i.stack.imgur.com/Daqq2.png" rel="nofollow noreferrer">enter image description here</a></p>
  
  <p><a href="https://i.stack.imgur.com/ydXJZ.png" rel="nofollow noreferrer">enter image description here</a></p>
  
  <p>and if I go to localhost:8000/get and the page is empty。req.body.length is empty   why? </p>