<p>选择图片附件</p>
<div class="upload">
  <div class="upload_warp_left" @click="fileClick" >
    <button class="btn btn-success">上传图片</button>
  </div>
  <div class="upload_warp_text">
    已选中{{imgList.length}}张图片
  </div>
  <div class="upload_warp" style="border: 1px solid white;">
    <div class="upload_warp_img" v-show="imgList.length!=0" >
      <div class="upload_warp_img_div" v-for="(item,index) of imgList" >
        <div class="upload_warp_img_div_top" >
          <div class="upload_warp_img_div_text" >
            {{item.file.name}}
          </div>
          <img src="../../../static/images/delete.png" class="upload_warp_img_div_del" @click="fileDel(index)">
        </div>
        <img :src="item.file.src">
      </div>
    </div>
  </div>
  <input type="file" id="files" ref="files" multiple v-on:change="handleFilesUpload($event)" style="display: none"/>
 <!-- <input v-on:change="fileChange()" ref="files" type="file" id="files"  multiple />-->
</div>

样式
.upload_warp_img_div_del {
  position: absolute;
  top: 6px;
  width: 16px;
  right: 4px;
}

.upload_warp_img_div_top {
  position: absolute;
  top: 0;
  width: 100%;
  height: 30px;
  background-color: rgba(0, 0, 0, 0.4);
  line-height: 30px;
  text-align: left;
  color: #fff;
  font-size: 12px;
  text-indent: 4px;
}

.upload_warp_img_div_text {
  white-space: nowrap;
  width: 80%;
  overflow: hidden;
  text-overflow: ellipsis;
}

.upload_warp_img_div img {
  max-width: 100%;
  max-height: 100%;
  vertical-align: middle;
}

.upload_warp_img_div {
  position: relative;
  height: 100px;
  width: 120px;
  border: 1px solid #ccc;
  margin: 0px 5px 5px 0px;
  float: left;
  line-height: 100px;
  display: table-cell;
  text-align: center;
  background-color: #eee;
  cursor: pointer;
}

.upload_warp_img {

  padding: 5px 0 0 5px;
  overflow: hidden
}

.upload_warp_text {
  text-align: left;
  margin-bottom: 5px;
  padding-top: 5px;
  text-indent: 14px;
  border-top: 1px solid #ccc;
  font-size: 14px;
}

.upload_warp_right {
  float: left;
  width: 57%;
  margin-left: 2%;
  height: 100%;
  border: 1px dashed #999;
  border-radius: 4px;
  line-height: 130px;
  color: #999;
}

.upload_warp_left button {
  margin: 8px 5px 0px 5px;
  cursor:pointer;
}

.upload_warp_left {
  float: left;
}

.upload_warp {
  margin: 5px;
}

.upload {
  border-left: 1px solid #ccc;
  border-right: 1px solid #ccc;
  background-color: #fff;

  box-shadow: 0px 1px 0px #ccc;
  border-radius: 4px;
}

定义全局的formdata

let formData;
export default {

}
mounted () {
  this.formData = new FormData();
},

methods:{

  addIrrInfor(){  //上传按钮
      let config = {
        headers: {
          'Content-Type': 'multipart/form-data'  //之前说的以表单传数据的格式来传递fromdata
       }
      }；
      formData.append('a','aa'); //appeend其他参数
       this.$axios.post(上传地址,formData,config
          ).then((response) => {
            if(response.data.stateCode === 200){
              alert("成功")
            }
          }) .catch((error) =>{
            console.log(error);
          });
      
  },

  fileClick(){  //点击选择图片按钮
    document.getElementById('files').click()
  },
  handleFilesUpload(el){   //一定要在这选择一次时，append一次
    this.filesArr=this.$refs.files.files
    //console.log(this.filesArr)
    for( var i = 0; i < this.filesArr.length; i++ ){
      formData.append('file',this.filesArr[i]);
    }
    if (!el.target.files[0].size) return;
    this.fileList(el.target.files);

  },
  fileList(files){
    for (let i = 0; i < files.length; i++) {
      this.fileAdd(files[i]);
    }
  },
  fileAdd(file){
    this.size = this.size + file.size;//总大小
    let reader = new FileReader();
    reader.vue = this;
    reader.readAsDataURL(file);
    reader.onload = function () {
      file.src = this.result;
      this.vue.imgList.push({
        file
      });
    }
  },
  fileDel(index){  //删除已选择的图片
    this.size = this.size - this.imgList[index].file.size;//总大小
    this.imgList.splice(index, 1);
  },
 
},

后端代码：

public void saveComplaintInfo(ComplaintInfo complaint, List<MultipartFile> file, HttpServletRequest request) {
    complaint.setId(UUID.randomUUID().toString());
    complaint.setCreate_time(DateUtils.DateFormatUnit.DATE_TIME.getDateStr(new Date()));
    complaint.setJk_allocate_status(0);
    complaint.setGu_allocate_status(0);
    complaint.setProcess_status(0);
    String url = "";       //保存的文件名

    for(MultipartFile picture: file){
        String orgFileName = picture.getOriginalFilename();
        String sname = orgFileName.substring(orgFileName.lastIndexOf("."));
        String id= UUID.randomUUID().toString()+sname;
       // File saveFile = new File(request.getSession().getServletContext().getRealPath("/upload/") + id);
          File saveFile = new File("/home/file/"+ id);
       // File saveFile = new File("E:/"+ id);
        if (!saveFile.getParentFile().exists()) {
            saveFile.getParentFile().mkdirs();
        }
        url += id + ",";
        try {
            BufferedOutputStream out = new BufferedOutputStream(new FileOutputStream(saveFile));
            out.write(picture.getBytes());
            out.flush();
            out.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    if(!url.equals("")){
        url.substring(0,url.length()-1);      //去除最后一个逗号
    }
    complaint.setPicture_name(url);
    complaintDao.save(complaint);
}

@RequestMapping("/saveComplaintInfo")
    @ResponseBody
    public JSONObject saveComplaintInfo(ComplaintInfo complaint, @RequestParam(value = "file",required = false) List<MultipartFile> file, HttpServletRequest request, HttpServletResponse response) {
        ResultOMUI result = new ResultOMUI(CommUtils.SUCCODE);
        response.setContentType("text/html;charset=utf-8");
        try{
            //@RequestBody ComplaintInfo complaint,
//            ComplaintInfo complaint = new ComplaintInfo();
//            complaint.setComplaint_title("测试");
            complaintService.saveComplaintInfo(complaint,file,request);
            result.setData("");
            result.setMessage("新增成功");
        }catch(Exception e){
            result.setData("服务器错误");
            result.setStateCode(CommUtils.ERRCODE);
            LOGGER.error(new SimpleDateFormat("yyyy年MM月dd日 HH时mm分ss秒").format(new Date()) + "--保存用户信息失败！", e.getMessage());
        }
        return JSONObject.fromObject(result);
    }