优化代码Set<String> rdsSet = new HashSet<>(); Set<String> empSet = new HashSet<>(); int rdsPageNum = 1; int empPageNum = 1; boolean rdsFinished = false; boolean empFinished = false; while (!rdsFinished || !empFinished) { if (!rdsFinished) { PageHelper.startPage(rdsPageNum, 1000); List<String> accountCode = idmEmployeeMapper.getaccountCode(); if (accountCode.isEmpty()) { rdsFinished = true; } else { rdsSet.addAll(accountCode); rdsPageNum++; } } if (!empFinished) { PageHelper.startPage(empPageNum, 1000); List<String> userId = idmEmployeeMapper.getEmployeeUserId(); if (userId.isEmpty()) { empFinished = true; } else { empSet.addAll(userId); empPageNum++; } } } List<String> result = new ArrayList<>(empSet); result.removeAll(rdsSet);

可以考虑将两个while循环合并成一个，减少重复代码。同时，可以使用Set的addAll方法来添加元素，避免每次添加都需要遍历一遍。最终代码可优化为：

Set<String> rdsSet = new HashSet<>();
Set<String> empSet = new HashSet<>();
int rdsPageNum = 1;
int empPageNum = 1;
boolean rdsFinished = false;
boolean empFinished = false;

while (!rdsFinished || !empFinished) {
    List<String> accountCode = new ArrayList<>();
    List<String> userId = new ArrayList<>();

    if (!rdsFinished) {
        PageHelper.startPage(rdsPageNum, 1000);
        accountCode = idmEmployeeMapper.getaccountCode();
        if (accountCode.isEmpty()) {
            rdsFinished = true;
        } else {
            rdsSet.addAll(accountCode);
            rdsPageNum++;
        }
    }

    if (!empFinished) {
        PageHelper.startPage(empPageNum, 1000);
        userId = idmEmployeeMapper.getEmployeeUserId();
        if (userId.isEmpty()) {
            empFinished = true;
        } else {
            empSet.addAll(userId);
            empPageNum++;
        }
    }

    // 如果两个列表都为空，则跳出循环
    if (accountCode.isEmpty() && userId.isEmpty()) {
        break;
    }
}

List<String> result = new ArrayList<>(empSet);
result.removeAll(rdsSet);