mongodb grouping and subgrouping with java driver -

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i need query mongodb db in such way kind of data hierarchy grouping field1 , field2. shell can run following:

db.collection.aggregate([{'$group': {'count': {'$sum': 1}, '_id': {'field1': '$field1', 'field2': '$field2'}}}])

does did same java?

it better if provide sample document.

you can convert query mongo-java driver following:

dbcollection collection = db.getcollection("collectionname");  dbobject groupfieldsinid = new basicdbobject(); groupfieldsinid.put( "field1", "$field1"); groupfieldsinid.put( "field2", "$field2"); dbobject groupfields = new basicdbobject( "_id", groupfieldsinid); groupfields.put("count", new basicdbobject( "$sum", 1)); dbobject group = new basicdbobject("$group", groupfields ); aggregationoutput output = collection.aggregate(group);

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