SpringBoot如何实现一个实时更新的进度条的示例代码

<div class="progress progress-striped active">
  <div class="progress-bar progress-bar-success" role="progressbar"
     aria-valuenow="60" aria-valuemin="0" aria-valuemax="100"
     style="width: 40%;">
    40%
  </div>
</div>

//点击确认导入执行此方法
function bulkImportChanges() {
  //获取批量操作状态文件
  var files = $("#importChanges").prop("files");
  var changesFile = files[0];
  var formData = new FormData();
  formData.append("importFile",changesFile);
  $.ajax({
    type : 'post',
    url : "/risk/bulk***es",
    data : formData,
    processData : false,   //文件ajax上传要加这两个的，要不然上传不了
    contentType : false,   //
    success : function(obj) {
      //导入成功
      if (obj.rspCode == "00") {
        //定时任务获取redis导入修改进度
        var progress = "";
        var timingTask = setInterval(function(){
          $.ajax({
            type: 'post',
            url: "/risk/t***k",
            dataType : 'json',
            success: function(result) {
              progress = result.value;
              if (progress != "error"){
                var date = progress.substring(0,6);
                //这里更新进度条的进度和数据
                $(".progress-bar").width(parseFloat(date)+"%");
                $(".progress-bar").text(parseFloat(date)+"%");
              }
            }
          });
          //导入修改完成或异常（停止定时任务）
          if (parseInt(progress)==100 || progress == "error") {
            //清除定时执行
            clearInterval(timingTask);
            $.ajax({
              type: 'post',
              url: "/risk/de***ess",
              dataType : 'json',
              success: function(result) {
                $("#bulkImportChangesProcessor").hide();
                if (parseInt(progress) == 100) {
                  alert("批量导入修改状态成功");
                }
                if (progress == "error") {
                  alert("批量导入修改状态失败");
                }
                //获取最新数据
                window.location.href="/risk/re***ByParam" rel="external nofollow" rel="external nofollow" ;
              }
            });
          }
        }, 1000)
      }else {
        $("#bulkImportChangesProcessor").hide();
        alert(obj.rspMsg);
        window.location.href="/risk/re***ByParam" rel="external nofollow" rel="external nofollow" ;
      }
    }
  });
}

/**
 * 退单管理批量修改状态导入文件
 * @param importFile
 * @return
 */
 @ResponseBody
 @RequestMapping("/bulk***es")
 public Map<String,Object> bulk***es(MultipartFile importFile){
   log.info("退单管理批量修改状态导入文件，传入参数："+importFile);
 Map<String,Object> map = new HashMap<>();
 List<Bulk***esEntity> fromExcel = null;
 try{
      //使用工具类导入转成list
  String[] header = {"sy***um","t***mt","ha***ult","re***nd","sy***nd","r**k"};
  fromExcel = importExcelUtil.importDataFromExcel(importFile, header, BulkImportChangesEntity.class);
  if (fromExcel.size()==0){
  map.put("rspCode","99");
  map.put("rspMsg","导入数据不能为空");
  return map;
  }
 }catch (Exception e){
  map.put("rspCode","99");
  map.put("rspMsg","导入操作表失败,请注意数据列格式");
  return map;
 }
 try {
  //这里会对list集合中的数据进行处理

  log.info("调用服务开始，参数："+JSON.toJSONString(fromExcel));
  //String url = p4_zuul_url+"/***/ri***eat/bu***nges";
  String url = p4_zuul_url+"/***-surpass/ri***eat/bu***nges";
  String result = HttpClientUtil.doPost(url,JSON.toJSONString(fromExcel));
  log.info("调用服务结束，返回数据："+result);
  if (result != null){
  map = JSONObject.parseObject(result, Map.class);
  log.info("批量修改状态导入："+JSON.toJSONString(map));
  }
 }catch (Exception e){
  map.put("rspCode","99");
  map.put("rspMsg","导入操作表失败");
  log.info("bu***es exception",e);
  return map;
 }
 return map;
 }

 /**
 * 获取退单管理批量修改状态导入文件进度条进度
 * @return
 */
 @ResponseBody
 @RequestMapping("/t***sk")
 public Map<String,Object> t***sk(){
 Map<String,Object> map = new HashMap<>();
    //获取redis值
 String progress = HttpClientUtil.doGet(
  p4_zuul_url + "/" + p4_redis + "/redis***ler/get?key=progressSchedule");
 if (progress != null){
  map = JSONObject.parseObject(progress, Map.class);
  log.info("进度条进度："+JSON.toJSONString(map));
  map.put("progressSchedule",progress);
 }else {
  HttpClientUtil.doGet(
   p4_zuul_url + "/" + p4_redis + "/redis***ler/del?key=progressSchedule");
 }
 return map;
 }

 /**
 * 清除redis进度条进度
 * @return
 */
 @ResponseBody
 @RequestMapping("/de***ess")
 public Map<String,Object> de***ess(){
 Map<String,Object> map = new HashMap<>();
 String progress = HttpClientUtil.doGet(
  p4_zuul_url + "/" + p4_redis + "/redis***ler/del?key=progressSchedule");
 if (progress != null){
  map = JSONObject.parseObject(progress, Map.class);
  log.info("返回数据："+JSON.toJSONString(map));
 }
 return map;
 }

@Async//开启异步
 @Transactional(rollbackFor = Exception.class)//事务回滚级别
 @Override
 public void bulkImportChanges(List<BulkImportChangesParam> list) {
 //初始化进度
 Double progressBarSchedule = 0.0;
 redisClient.set("progressSchedule", progressBarSchedule + "");//存redis
 try {
  for (int i = 1; i <= list.size(); i++) {
  RiskRetreatEntity entity = riskRetreatMapper.selectRetreatListBySysRefNum(list.get(i-1).getSysRefNum());
  if (entity == null){
   //查询结果为空直接进行下次循环不抛出
   continue;
  }
  //实体封装
        ···
        //更新
  riskRetreatMapper.updateRetreatByImport(entity);
  //计算修改进度并存放redis保存(1.0 / list.size())为一条数据进度
  progressBarSchedule = (1.0 / list.size()) * i*100;
  redisClient.set("progressSchedule", progressBarSchedule+"");
  if (i==list.size()){
   redisClient.set("progressSchedule", "100");
  }
  }
 }catch (Exception e){
  //当发生错误则清除缓存直接抛出回滚
  redisClient.set("progressSchedule","error");
  log.info("导入更新错误，回滚");
  log.info("bulkImportChanges exception:",e);
  throw e;
 }
 }

@EnableAsync
···//其他注解
public class Application {
  public static void main(String[] args) {
    SpringApplication.run(Application.class, args);
  }
}