引入js

  <script th:src="@{/js/ajaxfileupload.js}"></script>

html

<tr>
        <td>附件:</td>
        <td>
             <input type="hidden" id="insertcyefuji"  name="fuji" />
             <input type="file"  id="uploadcyefuji"  name="file" />
        </
 
td>
</tr>

js代碼-----選擇完文件後自動上傳

$(‘input[id="uploadcyefuji"]‘).change(function(e){
              var formData = new FormData();
                formData.append(‘file‘, $(‘#uploadcyefuji‘)[0].files[0]);
                $.ajax({
                    url: ‘/fileUpload‘,
                    type: ‘POST‘,
                    cache: false,
                    data: formData,
                    processData: false,
                    contentType: false
                }).done(function(res) {
                    alert("上傳成功")
                }).fail(function(res) {
                    alert("上傳失敗");
                });
     
 })
 

controller後臺代碼

 1 /**
 2      * 實現文件上傳
 3      * @throws IOException 
 4      * @throws IllegalStateException 
 5      * */
 6     @RequestMapping(value="fileUpload",method = RequestMethod.POST)
 7     @ResponseBody 
 8     public String fileUpload(HttpServletRequest req,MultipartFile file) throws
 
 IllegalStateException, IOException{
 9         if(file.getOriginalFilename()==null||file.getOriginalFilename().equals("")){
10             System.err.println("為空++++");
11             return "";
12         }else{
13             String picName = UUID.randomUUID().toString();
14             // 獲取文件名
15             String oriName = file.getOriginalFilename();
16                 System.err.println(oriName+"圖片名字");
17             // 獲取圖片後綴
18             String extName = oriName.substring(oriName.lastIndexOf("."));
19                 System.err.println("後綴名字"+extName);
20             if(extName.equals(".jpg") || extName.equals(".JPG")  ||extName.equals(".png") ||  extName.equals(".PNG")){
21                 String path = req.getSession().getServletContext().getRealPath("/");
22                 System.out.println("path="+path);
23                 
24                 file.transferTo(new File(path+"upload/"+picName + extName));
25                 //user.setUsername(picName + extName);
26                 //m.addAttribute("fileName"+count, picName + extName);
27                 //count--;
28                 //list.add(user);
29                
30                 // 設置圖片名到商品中
31                 System.err.println("上傳圖片完成");
32                 return "上傳成功";
33             }else {
34                 System.err.println("格式不對");
35                 return "格式不對"; 
36                
37             }
38         }
39 }

springmvc_ajax異步上傳文件(基於ajaxfileupload.js)