Java – MongoDB aggregation using Java

I

use GroupOperation in java to group fields and calculate values, but I don’t get the results I want.

I’m using Mongo Operation to connect to MongoDB via Java. I can group based on the field “Company”, but the count is always 0. I can’t figure out why.

GroupOperation 
group=Aggregation.group("company").sum("company").as("count");
    Aggregation aggregation=Aggregation.newAggregation(group);
    AggregationResults<ResultMap> orderAggregate = 
mongoOperations.aggregate(aggregation,EmpDesc.class,ResultMap.class);

orderAggregate.getMappedResults().forEach(s->System.out.println("^^ 
"+s.toString()));

Always get:

 ResultMap [company=ABC, count=0]
 ResultMap [company=XYZ, count=0]

It should be

Aggregation.group("company").count().as("count");