Spring Data MongoDb是否支持$ filter数组聚合运算符？

您可以通过提供自己的解决方案来解决此问题

Aggregationexpression

ProjectionOperation agg = Aggregation.project() //      .and(new Aggregationexpression() {        @Override        public DBObject toDbObject(AggregationOperationContext context) {          DBObject filterexpression = new BasicDBObject();          filterexpression.put("input", "$answer_list");          filterexpression.put("as", "answer");          filterexpression.put("cond", new BasicDBObject("$eq2", Arrays.<Object> asList("$$answer.question", 2)));          return new BasicDBObject("$filter", filterexpression);        }      }).as("profile");