解释一下这段代码 if (!CollectionUtils.isEmpty(maritalItems) && !CollectionUtils.isEmpty(specialItems)) { Iterator<ItemsInfo> iterator = maritalItems.iterator(); while (iterator.hasNext()) { ItemsInfo maritalItem = iterator.next(); for (ItemsInfo specialItem : specialItems) { if (maritalItem.getItemId().equals(specialItem.getItemId())) { i++; iterator.remove(); break; } } }

这段代码是在判断maritalItems这个集合是否为空。

CollectionUtils是Apache Commons Collections库中的一个工具类，isEmpty方法用于判断集合是否为空。如果maritalItems集合为空，那么if语句中的条件为true，将会执行if语句块中的代码。如果maritalItems集合不为空，那么if语句中的条件为false，将不会执行if语句块中的代码。

相关问题

for (DatabaseType d : dataTypes) { DatabaseContextHolder.setDatabaseType(d); List<String> bankPaidOutRefNbrs = unionLoanMapper.getCustPaidOutRefNbrsUnionLoan(); if(!CollectionUtils.isEmpty(bankPaidOutRefNbrs)){ DatabaseContextHolder.setDatabaseType(d); List<PaidOutRemainBalVo> unionBankBals = unionLoanMapper.getUnionBalByRefNbrs(bankPaidOutRefNbrs); List<String> refNbrs = unionBankBals.stream().map(p -> p.getRefNbr()).collect(Collectors.toList()); DatabaseContextHolder.setDatabaseType(d); List<String> waiveRefNbrs = new ArrayList<>(); if (!CollectionUtils.isEmpty(refNbrs)){ waiveRefNbrs = unionLoanMapper.getUnionWaiveRefNbr(refNbrs); } Iterator<PaidOutRemainBalVo> iterator = unionBankBals.iterator(); while (iterator.hasNext()) { PaidOutRemainBalVo vo = iterator.next(); //排除豁免未入账 if (!CollectionUtils.isEmpty(waiveRefNbrs)) { if (waiveRefNbrs.contains(vo.getRefNbr())) { iterator.remove(); continue; } } //去除三峡本金为负数的告警 if (vo.getCoopId() != null && vo.getCoopId().contains("SXBANK") && vo.getPrincipalBal().compareTo(BigDecimal.ZERO) < 0) { iterator.remove(); } } if (!CollectionUtils.isEmpty(unionBankBals)){ unionBalsAll.addAll(unionBankBals); } } } 用多线程实现该循环

可以使用Python内置的`concurrent.futures`模块中的`ThreadPoolExecutor`来实现多线程循环。具体代码如下：

from concurrent.futures import ThreadPoolExecutor
from functools import partial

def process_data(d, data):
    DatabaseContextHolder.setDatabaseType(d)
    bankPaidOutRefNbrs = unionLoanMapper.getCustPaidOutRefNbrsUnionLoan()
    if not bankPaidOutRefNbrs:
        return []
    DatabaseContextHolder.setDatabaseType(d)
    unionBankBals = unionLoanMapper.getUnionBalByRefNbrs(bankPaidOutRefNbrs)
    refNbrs = [p.getRefNbr() for p in unionBankBals]
    DatabaseContextHolder.setDatabaseType(d)
    waiveRefNbrs = unionLoanMapper.getUnionWaiveRefNbr(refNbrs) if refNbrs else []
    result = []
    for vo in unionBankBals:
        if waiveRefNbrs and vo.getRefNbr() in waiveRefNbrs:
            continue
        if vo.getCoopId() and "SXBANK" in vo.getCoopId() and vo.getPrincipalBal() < 0:
            continue
        result.append(vo)
    return result

dataTypes = [...]
with ThreadPoolExecutor(max_workers=2) as executor:
    func = partial(process_data, data=dataTypes)
    results = executor.map(func, dataTypes)
    unionBalsAll = []
    for result in results:
        if result:
            unionBalsAll.extend(result)

以上代码中，我们将原来的循环拆分成了一个`process_data`函数，并使用`partial`函数将`dataTypes`作为参数传递给该函数。接着，创建一个`ThreadPoolExecutor`实例，设置最大工作线程数为2。使用`map`方法将`process_data`函数提交给线程池，并传入`dataTypes`参数，得到一个生成器对象`results`。最后，遍历`results`并将结果存入`unionBalsAll`中。这样就实现了多线程循环。

优化这段代码 List<ThirdLogDetail> detailList = thirdLogDetailMapper.selectByExample(example); if (!detailList.isEmpty()&&detailList.size()>0) { ThirdLogDetail detail = detailList.get(0); if (detail.getFileMd5().equals(thirdLogDetail.getFileMd5())){ updateLogDetail(detail); log.info("ThirdLogDetail addLog querylogName重复:{},md5:{}", thirdLogDetail.getLogName(), thirdLogDetail.getFileMd5()); return detail; } }

这段代码可以进行如下优化：

1. 将 `!detailList.isEmpty()&&detailList.size()>0` 改为 `!detailList.isEmpty()`，因为 `List` 的 `isEmpty()` 方法已经包含了 `size()>0` 的判断。

2. 将 `detailList.get(0)` 改为 `detailList.iterator().next()`，因为这样可以避免在 `detailList` 为空时出现 `IndexOutOfBoundsException` 异常。

3. 将 `detail.getFileMd5().equals(thirdLogDetail.getFileMd5())` 改为 `Objects.equals(detail.getFileMd5(),thirdLogDetail.getFileMd5())`，因为这样可以避免在 `detail.getFileMd5()` 或 `thirdLogDetail.getFileMd5()` 为 `null` 时出现 `NullPointerException` 异常。

优化后的代码如下：

List<ThirdLogDetail> detailList = thirdLogDetailMapper.selectByExample(example);
if (!detailList.isEmpty()) {
    ThirdLogDetail detail = detailList.iterator().next();
    if (Objects.equals(detail.getFileMd5(), thirdLogDetail.getFileMd5())) {
        updateLogDetail(detail);
        log.info("ThirdLogDetail addLog querylogName重复:{},md5:{}", thirdLogDetail.getLogName(), thirdLogDetail.getFileMd5());
        return detail;
    }
}