Spring - mongodb - aggregation - The 'cursor' option is required

Question

Executing the following aggregation pipeline:

public void getMostLikedItems () {
        UnwindOperation unwind = Aggregation.unwind(\"favoriteItems\");
             


        

Answer 1

You can provide outputmode as cursor as providing a cursor is mandatory

List list = new ArrayList();
list.add(unwind.toDBObject(Aggregation.DEFAULT_CONTEXT));
list.add(group.toDBObject(Aggregation.DEFAULT_CONTEXT));
list.add(sort.toDBObject(Aggregation.DEFAULT_CONTEXT));

DBCollection col = mongoTemplate.getCollection("users");

Cursor cursor = col.aggregate(list, AggregationOptions.builder().allowDiskUse(true).outputMode(OutputMode.CURSOR).build());

List result = new ArrayList();

while(cursor.hasNext()) {
     DBObject object = cursor.next();
     result.add(new AggregationResultVO(object.get("aggregationResultId").toString()));
}