把下面代码修改为根据pushMailboxList的数量按每10条为一批多线程分批执行 pushMailboxList.stream().forEach(item -> { Township byId = townshipService.getById(item.getPushOrgid()); try { String email = byId.getEmail(); if (StrUtil.isNotBlank(email)) { String date = DateTime.now().toString(DatePattern.CHINESE_DATE_TIME_PATTERN); String content = "金平县气象局于" + date + "，发布了" + repProductContent.getReportName() + "气象服务通知，请您查收并注意做好防范工作。"; //发送邮件 MailUtil.send(email, repProductContent.getReportName(), content, false, FileUtil.file(filePath)); item.setIzEmailSuccess(1); pushMailboxList1.add(item); } else { item.setIzEmailSuccess(0); pushMailboxList1.add(item); } } catch (Exception e) { item.setIzEmailSuccess(0); pushMailboxList1.add(item); e.printStackTrace(); } });

将代码修改为根据 pushMailboxList 的数量按每 10 条为一批使用多线程分批执行的代码可能长这样:

List<List<PushMailbox>> pushMailboxLists = Lists.partition(pushMailboxList, 10);

for (List<PushMailbox> list : pushMailboxLists) {
    // 使用多线程运行
    ExecutorService executor = Executors.newFixedThreadPool(list.size());
    for (PushMailbox item : list) {
        executor.execute(() -> {
            Township byId = townshipService.getById(item.getPushOrgid());
            try {
                String email = byId.getEmail();
                if (StrUtil.isNotBlank(email)) {
                    String date = DateTime.now().toString(DatePattern.CHINESE_DATE_TIME_PATTERN);
                    String content = "金平县气象局于" + date + "，发布了" + repProductContent.getReportName() + "气象服务通知，请您查收并注意做好防范工作。";
                    //发送邮件
                    MailUtil.send(email, repProductContent.getReportName(), content, false, FileUtil.file(filePath));
                    item.setIzEmailSuccess(1);
                    pushMailboxList1.add(item);
                } else {
                    item.setIzEmailSuccess(0);
                    pushMailboxList1.add(item);
                }
            } catch (Exception e) {
                item.setIzEmailSuccess(0);
                pushMailboxList1.add(item);
                e.printStackTrace();
            }
        });
    }
    executor.shutdown();
    while (!executor.isTerminated()) {
    }
}

注意，上面的代码是假设 pushMailboxList 中的元素个数为n，则将其分为 n/10 个列表。每个列表都会在一个单独的线程中并行执行。