优化以下代码List<SalaryBillListOfPermits> salaryBillListOfPermitsList = new ArrayList<>(); for (OnWorkingEmployeeVO onWorkingEmployee : onWorkingEmployees) { Integer numbs = hrmSalaryBillRecordDAO.getCountByCorpIdAndUserId(param.getCorpId(), onWorkingEmployee.getUserId()); SalaryBillListOfPermits salaryBillListOfPermits = new SalaryBillListOfPermits(); salaryBillListOfPermits.setNumbs(numbs); salaryBillListOfPermits.setDeptName(onWorkingEmployee.getMainDeptName()); salaryBillListOfPermits.setJobNumber(onWorkingEmployee.getEmpJobNumber()); salaryBillListOfPermits.setPersonId(onWorkingEmployee.getUserId()); salaryBillListOfPermits.setPersonName(onWorkingEmployee.getName()); salaryBillListOfPermitsList.add(salaryBillListOfPermits); }

可以优化的地方有以下几点：

1. 减少数据库查询次数：可以使用一条 SQL 语句查询出所有员工的薪资单数量，避免每个员工都要单独查询一次。比如可以使用 `IN` 关键字将所有员工的 ID 拼接成一个字符串，然后在 SQL 语句中使用 `WHERE user_id IN (id1, id2, ...)` 来查询。

2. 使用 stream API：可以使用 Java 8 引入的 stream API 来简化代码。比如可以使用 `stream().map()` 将 `onWorkingEmployees` 转换成 `SalaryBillListOfPermits` 列表，然后使用 `collect(Collectors.toList())` 将其收集起来。

优化后的代码如下：

List<Integer> userIds = onWorkingEmployees.stream()
        .map(OnWorkingEmployeeVO::getUserId)
        .collect(Collectors.toList());

Map<Integer, Integer> salaryBillCounts = hrmSalaryBillRecordDAO.getCountsByCorpIdAndUserIds(param.getCorpId(), userIds);

List<SalaryBillListOfPermits> salaryBillListOfPermitsList = onWorkingEmployees.stream()
        .map(onWorkingEmployee -> {
            Integer numbs = salaryBillCounts.getOrDefault(onWorkingEmployee.getUserId(), 0);

            SalaryBillListOfPermits salaryBillListOfPermits = new SalaryBillListOfPermits();
            salaryBillListOfPermits.setNumbs(numbs);
            salaryBillListOfPermits.setDeptName(onWorkingEmployee.getMainDeptName());
            salaryBillListOfPermits.setJobNumber(onWorkingEmployee.getEmpJobNumber());
            salaryBillListOfPermits.setPersonId(onWorkingEmployee.getUserId());
            salaryBillListOfPermits.setPersonName(onWorkingEmployee.getName());
            return salaryBillListOfPermits;
        })
        .collect(Collectors.toList());