根据地区进行统计人数，如果没有显示为0

//Controller 层
/**
 * @Description
 * 根据地区查询所有用户信息
 * @author luying
 *
 */

@RequestMapping(value = "/toShiCountPage")
@ResponseBody
public ModelAndView toShiCountPage(Integer cid) {
    ModelAndView mv = new ModelAndView("admin/tosignup/toShiCountPage");
//    查询到所有地市级的人数统计
   Map<String,Object> areaPersonMap = toSignUpService.areaPersonNum(cid);
   mv.addObject("cid",cid);
   mv.addObject("areaPersonMap",areaPersonMap);
    return mv;
}

//service 层
/**
 * @Description
 *
 * 根据地区进行人员数量统计
 * @author luying
 *
 */
public Map<String,Object> areaPersonNum(Integer cid){
    List<ApplyParticipants> areaNum=null;
    Map mapArea = new HashMap<>();
 
    mapArea.put("桂林市","0");
    mapArea.put("北海市","0");
    mapArea.put("梧州市","0");
    mapArea.put("贵港市","0");
    mapArea.put("玉林市","0");
    mapArea.put("河池市","0");
    mapArea.put("百色市","0");
    mapArea.put("钦州市","0");
    mapArea.put("崇左市","0");
    mapArea.put("柳州市","0");
    mapArea.put("贺州市","0");
    mapArea.put("防城港市","0");
    mapArea.put("来宾市","0");
    try {
        areaNum=participantsMapper.countArea(cid);
        for(ApplyParticipants applyParticipants:areaNum){
            mapArea.put(applyParticipants.getArea(),applyParticipants.getNum());
        }

    } catch (Exception e) {
        e.printStackTrace();
    }
    return mapArea;
}

根据地区进行统计人数，如果没有显示为0

原文：https://www.cnblogs.com/luYing666/p/11590646.html