<!DOCTYPE html>
<html>
  <head>
    <title>test</title>
  </head>
  <body>
    <input type="file" id="fileUpload">
    <button id="submit">点击上传文件</button>
<script src="javascripts/jquery-3.2.1.min.js"></script>//此处需自己引入jquery文件
<script>
//方法一:原生ajax上传文件
document.getElementById(‘submit‘).onclick = function(){
var file = document.getElementById(‘fileUpload‘).files[0];
   var formData = new FormData();
   formData.append(‘name‘,‘libin‘);
   formData.append(‘userFile‘,file);
   var oFileBody = ‘<a id="a"><b id="b">hey!</b></a>‘; // Blob对象包含的文件内容
   var oBlob = new Blob([oFileBody], { type: "text/xml"});
   var oReq = new XMLHttpRequest();
   oReq.open("POST", "http://localhost:3000/formUpload");
// 文件上传完毕的回调
oReq.upload.onloadend = function(e) {
  console.log(‘接收完成‘+e.loaded+‘/‘+e.total);
}
oReq.send(formData);
//方法二:通过jquery的ajax方法上传文件
 document.getElementById(‘submit‘).onclick = function(){
   var file = document.getElementById(‘fileUpload‘).files[0];
   var formData = new FormData();
   formData.append(‘name‘,‘libin‘);
   formData.append(‘userFile‘,file);
   $.ajax({
       url: ‘http://localhost:3000/formUpload‘,
       data: formData,
       contentType: false,
       processData: false,
       type: ‘POST‘,
       success: function (result) {
           console.log(result);
       },
       error: function (err) {
           console.error(err);
       }
   });
 }
</script>
</body>
</html>