List<RsysMenu> rootMenus = list.stream().filter(item -> "M".equals(item.getParentId())).sorted().collect(Collectors.toList()); List<RsysMenu> rootMenus = list.stream().filter(item -> "M".equals(item.getParentId())).sorted().collect(Collectors.toList()); List<RsysMenu> rootMenus = list.stream().filter(item -> "M".equals(item.getParentId())).sorted().collect(Collectors.toList()); List<RsysMenu> rootMenus = list.stream().filter(item -> "M".equals(item.getParentId())).sorted().collect(Collectors.toList()); List<RsysMenu> rootMenus = list.stream().filter(item -> "M".equals(item.getParentId())).sorted().collect(Collectors.toList());

这段代码是一个Java代码片段，它的作用是从一个列表中过滤出所有父节点为"M"的菜单项，并按照一定规则进行排序，最后将结果收集到一个新的列表中。

首先，通过使用`stream()`方法将列表转换为流，然后使用`filter()`方法过滤出父节点为"M"的菜单项。接着，使用`sorted()`方法对菜单项进行排序。最后，使用`collect()`方法将过滤和排序后的菜单项收集到一个新的列表中。

请注意，代码中多次出现的重复行是输入错误，应该删除多余的行。正确的代码应该是这样的：

List<RsysMenu> rootMenus = list.stream()
    .filter(item -> "M".equals(item.getParentId()))
    .sorted()
    .collect(Collectors.toList());

这样，你就可以得到一个包含所有父节点为"M"的菜单项，并按照排序规则排列的列表。

相关问题

优化这段代码：List<CompletableFuture<CallIntersectionVo>> futureList = Lists.newArrayList(); for (Map.Entry<String, List<String>> entry : intersectionResult.entrySet()) { CompletableFuture<CallIntersectionVo> future = CompletableFuture.supplyAsync(() -> { String account = entry.getKey(); List<String> personNoList = entry.getValue().stream().distinct().collect(Collectors.toList()); CallIntersectionVo vo = new CallIntersectionVo(); if (personNoList.size() >= 2) { List<PersonBasicVo> personVoList = Lists.newArrayList(); int count = 0; for (String personNo : personNoList) { Map<String, Object> callMap = callMapList.stream().filter(map -> personNo.equals(map.get("personNo"))).findAny().get(); List<CallRecord> callList = (List<CallRecord>) callMap.get("callList"); // 统计通话频率 count += callList.stream().filter(x -> account.equals(x.getRelationshipAccount())).count(); // 获取涉案人 personVoList.add(personList.stream().filter(person -> personNo.equals(person.getPersonNo())).findAny().get()); } // 共同号码是否属于涉案人 String commonPersonName = getCommonPersonName(personList, account); if (frequency != null && frequency > 0) { if (count >= frequency) { vo.setPersons(personVoList); vo.setCommonAccount(account); vo.setFrequency(count); vo.setCommonPersonName(commonPersonName); } return vo; } else { vo.setPersons(personVoList); vo.setCommonAccount(account); vo.setFrequency(count); vo.setCommonPersonName(commonPersonName); return vo; } } else { return vo; } }, executor); futureList.add(future); } voList.addAll(futureList.stream().map(CompletableFuture::join) .distinct().sorted(Comparator.comparing(vo -> vo.getPersons().size())) .collect(Collectors.toList()));

优化后的代码如下：

List<CompletableFuture<CallIntersectionVo>> futureList = intersectionResult.entrySet().stream()
        .map(entry -> CompletableFuture.supplyAsync(() -> {
            String account = entry.getKey();
            List<String> personNoList = entry.getValue().stream().distinct().collect(Collectors.toList());
            CallIntersectionVo vo = new CallIntersectionVo();
            if (personNoList.size() >= 2) {
                List<PersonBasicVo> personVoList = personNoList.stream()
                        .map(personNo -> {
                            Map<String, Object> callMap = callMapList.stream()
                                    .filter(map -> personNo.equals(map.get("personNo")))
                                    .findAny()
                                    .orElseThrow(() -> new NoSuchElementException("Person not found"));
                            List<CallRecord> callList = (List<CallRecord>) callMap.get("callList");
                            int count = (int) callList.stream().filter(x -> account.equals(x.getRelationshipAccount())).count();
                            return personList.stream()
                                    .filter(person -> personNo.equals(person.getPersonNo()))
                                    .findAny()
                                    .orElseThrow(() -> new NoSuchElementException("Person not found"));
                        })
                        .collect(Collectors.toList());
                String commonPersonName = getCommonPersonName(personList, account);

                vo.setPersons(personVoList);
                vo.setCommonAccount(account);
                vo.setFrequency(personVoList.size());
                vo.setCommonPersonName(commonPersonName);

                return vo;
            } else {
                return vo;
            }
        }, executor))
        .collect(Collectors.toList());

List<CallIntersectionVo> voList = futureList.stream()
        .map(CompletableFuture::join)
        .distinct()
        .sorted(Comparator.comparingInt(vo -> vo.getPersons().size()))
        .collect(Collectors.toList());

主要优化：
1. 使用流式编程，替换原来的for循环和entrySet遍历。
2. 使用`stream()`和`collect(Collectors.toList())`方法来收集结果，代替手动添加到列表中。
3. 使用`orElseThrow`方法来处理可能找不到元素的情况，避免空指针异常。
4. 将lambda表达式内联，使代码更简洁。
5. 使用`Comparator.comparingInt`方法来指定排序规则，避免编译器警告。

识别代码 @RequestMapping(value = "/common/tree", method = RequestMethod.GET) public ResponseInfo getCommentTree(Integer siteId, @RequestParam Short operator, HttpServletRequest request) throws GlobalException { if (siteId == null) { siteId = SystemContextUtils.getSiteId(request); } final Integer sid = siteId; List<Channel> channels = SystemContextUtils.getUser(request).getChannelsByOperator(siteId, operator); if (channels.size() > 0) { channels = channels.stream() .filter(channel -> !channel.getRecycle() && !channel.getHasDeleted() && channel.getSiteId().equals(sid)) .sorted(Comparator.comparing(Channel::getSortNum) .thenComparing( Comparator.comparing(Channel::getCreateTime))) .collect(Collectors.toList()); } return new ResponseInfo(super.getChildTree(channels, false, "name", "id", "editAble", "createChildAble", "deleteAble", "mergeAble", "staticAble", "permAssignAble", "viewAble")); }

这是一个 Java Spring 框架中的控制器方法，用于获取评论树形结构。其中 @RequestMapping 注解指定了请求的 URL 和请求方法，@RequestParam 注解指定了请求参数。代码中还包含了一些业务逻辑，如获取站点 ID、获取用户权限等。