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Spring Data MongoDB – Aggregation Grouping Example

In this tutorial, we will show you how to do the data grouping with Spring Data + MongoDB aggregation framework.

1. Test Data

domain.json

{ "_id" : 1, "domainName" : "test1.com", "hosting" : "hostgator.com" }
{ "_id" : 2, "domainName" : "test2.com", "hosting" : "aws.amazon.com"}
{ "_id" : 3, "domainName" : "test3.com", "hosting" : "aws.amazon.com" }
{ "_id" : 4, "domainName" : "test4.com", "hosting" : "hostgator.com" }
{ "_id" : 5, "domainName" : "test5.com", "hosting" : "aws.amazon.com" }
{ "_id" : 6, "domainName" : "test6.com", "hosting" : "cloud.google.com" }
{ "_id" : 7, "domainName" : "test7.com", "hosting" : "aws.amazon.com" }
{ "_id" : 8, "domainName" : "test8.com", "hosting" : "hostgator.com" }
{ "_id" : 9, "domainName" : "test9.com", "hosting" : "cloud.google.com" }
{ "_id" : 10, "domainName" : "test10.com", "hosting" : "godaddy.com" }
...
{ "_id" : 100, "domainName" : "test10.com", "hosting" : "godaddy.com" }

2. MongoDB Aggregation Example

MongoDB aggregation example to sum the total number of hosting :


db.domain.aggregate(
    {
	$match : {_id:{$lt:10}}
    },
    { 
	$group : {_id : "$hosting", total : { $sum : 1 }}
    },
    {
	$sort : {total : -1}
    }
);

Output


{ "_id" : "aws.amazon.com", "total" : 4 }
{ "_id" : "hostgator.com", "total" : 3 }
{ "_id" : "cloud.google.com", "total" : 2 }
{ "_id" : "godaddy.com", "total" : 1 }

2. Spring Data + MongoDB Aggregation Example

This is the equivalent example in Spring Data MongoDB.

DomainDaoImpl.java

package com.mkyong.core.domain.dao;

//imports as static
import static org.springframework.data.mongodb.core.aggregation.Aggregation.group;
import static org.springframework.data.mongodb.core.aggregation.Aggregation.match;
import static org.springframework.data.mongodb.core.aggregation.Aggregation.newAggregation;
import static org.springframework.data.mongodb.core.aggregation.Aggregation.project;
import static org.springframework.data.mongodb.core.aggregation.Aggregation.sort;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Sort;
import org.springframework.data.mongodb.core.MongoTemplate;
import org.springframework.data.mongodb.core.aggregation.Aggregation;
import org.springframework.data.mongodb.core.aggregation.AggregationResults;
import org.springframework.data.mongodb.core.query.Criteria;
import org.springframework.data.mongodb.core.query.Query;
import org.springframework.data.mongodb.core.query.Update;
import org.springframework.stereotype.Repository;
import com.mkyong.core.domain.model.Domain;
import com.mkyong.core.hosting.model.HostingCount;
import java.util.List;

@Repository
public class DomainDaoImpl implements DomainDao {

	@Autowired
	MongoTemplate mongoTemplate;
	
	public List<HostingCount> getHostingCount() {
	
		Aggregation agg = newAggregation(
			match(Criteria.where("_id").lt(10)),
			group("hosting").count().as("total"),
			project("total").and("hosting").previousOperation(),
			sort(Sort.Direction.DESC, "total")
				
		);

		//Convert the aggregation result into a List
		AggregationResults<HostingCount> groupResults 
			= mongoTemplate.aggregate(agg, Domain.class, HostingCount.class);
		List<HostingCount> result = groupResults.getMappedResults();
		
		return result;
		
	}
HostingCount.java

package com.mkyong.core.hosting.model;

public class HostingCount {

	private String hosting;

	private long total;

	//...
}
More Examples
Refer to this official Spring data – Aggregation Framework Support

References

  1. MongoDB – Aggregation Concepts
  2. MongoDB – Aggregate And Group Example
  3. Spring.io – Aggregation Framework Support

About Author

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Founder of Mkyong.com, love Java and open source stuff. Follow him on Twitter. If you like my tutorials, consider make a donation to these charities.

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???? ?????????
8 years ago

May yuo give me source code of this example please?.Unfortunately id doesn’t work for me. It give null result without any errors

???? ?????????
8 years ago

Ok. I solved my problem. I just commended ” match(Criteria.where(“_id”).lt(10))” May be it doesn’t work for me because i have LongNumber id

Arun Shiva
5 years ago

What is the Domain class

Arun Shiva
5 years ago

Can you please add the Domain class

ravi
5 years ago

I don’t want to give limit how should I do it.

choubani amir
5 years ago

does aggregation works with spring data mongodb in fields of nested array using DBREF?
I tried first aggregation of mongodb shell and I find that it does not work with references

Chiang
4 years ago
Reply to  choubani amir

If you want to use aggregations with references check out RelMongo https://github.com/kaiso/relmongo

pankaj
8 years ago

I am getting this error. Please help

java.lang.NoClassDefFoundError: org/springframework/data/mongodb/core/aggregation/AggregationOperation

Vincensius Adi Nugroho
8 years ago

hi, i got this error

errmsg” : “exception: aggregation result exceeds maximum document size (16MB)

guest
4 years ago

use the $AllowDiskUse in the Aggregation Query