private String newStaffId(String position) {
   if (position.equals("管理员")) {
     List<Staff> list = staffDao.findByPosition(position);
     int num = list.size() + 1;
     String id = "";
     if (num < 10) {
       id = "S" + "000" + num;
     } else if (100 > num && num >= 10) {
       id = "S" + "00" + num;
     } else if (1000 > num && num >= 100) {
       id = "S" + "0" + num;
     } else {
       id = "S" + num;
     }
     return id;
   } else if (position.equals("经理")) {
     List<Staff> list = staffDao.findByPosition(position);
     int num = list.size() + 1;
     String id = "";
     if (num < 10) {
       id = "A" + "000" + num;
     } else if (100 > num && num >= 10) {
       id = "A" + "00" + num;
     } else if (1000 > num && num >= 100) {
       id = "A" + "0" + num;
     } else {
       id = "A" + num;
     }
     return id;
   } else {
     List<Staff> list = staffDao.findByPosition(position);
     int num = list.size() + 1;
     String id = "";
     if (num < 10) {
       id = "C" + "000" + num;
     } else if (100 > num && num >= 10) {
       id = "C" + "00" + num;
     } else if (1000 > num && num >= 100) {
       id = "C" + "0" + num;
     } else {
       id = "C" + num;
     }
     return id;
   }
 }
  @Override
  public List<StaffInfo> searchStaffByProposition(String position) {
    List<StaffInfo> stafflist = new ArrayList<StaffInfo>();
    List<Staff> entitylist = staffDao.findByPosition(position);

    if (entitylist != null) {
      for (int i = 0; i < entitylist.size(); i++) {
        StaffInfo temp = convertEntity(entitylist.get(i));
        stafflist.add(temp);
      }
    }

    return stafflist;
  }