小编pet*_*iza的帖子

这是我的代码（Spring 数据）：

        MatchOperation matchOperation = Aggregation.match(new Criteria("stats.channelId").is(channelId));

        UnwindOperation unwindOperation = Aggregation.unwind("stats");

        GroupOperation groupOperation = Aggregation.group("id", "discordId")
                .push("stats").as("stats");

        AggregationOperation addFields = (AggregationOperationContext aggregationOperationContext) -> {
                DBObject dbObject =
                        new BasicDBObject("allGamesOnChannel",
                                new BasicDBObject("$sum", "$stats.pickupsPlayed"));
                return new BasicDBObject("$addFields", dbObject);
            };

        SortOperation sortOperation = Aggregation.sort(new Sort(Sort.Direction.DESC, "allGamesOnChannel"));
        LimitOperation limitOperation = Aggregation.limit(maxElements);

        ProjectionOperation projectionOperation = Aggregation.project("id", "discordId", "stats");

        Aggregation aggregation = Aggregation.newAggregation(matchOperation,unwindOperation, matchOperation,groupOperation,addFields,
                sortOperation,limitOperation,projectionOperation);

        AggregationResults<UserSummaryChannel> userSummaries = mongoTemplate.aggregate(aggregation, "pickupUser", UserSummaryChannel.class);

我在上面执行时遇到这个异常：

Caused by: java.lang.IllegalArgumentException: Invalid reference 'allGamesOnChannel'!
    at org.springframework.data.mongodb.core.aggregation.ExposedFieldsAggregationOperationContext.getReference(ExposedFieldsAggregationOperationContext.java:99) ~[spring-data-mongodb-1.10.10.RELEASE.jar:na]
    at org.springframework.data.mongodb.core.aggregation.ExposedFieldsAggregationOperationContext.getReference(ExposedFieldsAggregationOperationContext.java:80) ~[spring-data-mongodb-1.10.10.RELEASE.jar:na]
    at org.springframework.data.mongodb.core.aggregation.SortOperation.toDBObject(SortOperation.java:73) …

我希望能够以时间解析时间（天，小时，分钟）+可选的字符串，所以输入如下所示：<time>(white_spaces)<optional_string>。我知道正则表达式是处理这些事情的正确工具，所以我想出了这样的表达：

Pattern.compile("((?<days>\\d+)d)?((?<hours>\\d+)h)?((?<minutes>\\d+)m)?\\s+?(?<reason>.+)?");

基本上它按预期工作，但是在此表达式中，所有时间组（天、小时、分钟）都是可选的，我希望输入至少包含分钟组。但是，如果指定了小时或天，则不需要分钟。此外，时间组（d+h、h+m、d+m、d+h+m）的所有组合都是可能的。那么我该如何纠正我的表达呢？或者也许有其他方法来解析一段时间？

编辑：输入示例：

12h64m - 正确的

12d43m dsd - 正确的

- 空字符串 - 不正确