MongoTest.java

package com.smartbear.saas.rs.storage;

import com.github.fakemongo.Fongo;
import com.mongodb.util.JSONSerializers;
import org.jongo.Jongo;
import org.jongo.MongoCollection;
import org.junit.Test;

import static java.util.stream.Collectors.joining;

public class MongoTest
{
	@Test
	public void projectTest()
	{
		/*
		 	Get started with `help`
			To try out an interactive tutorial type `tutorial`
			> db.foo.insert( {bar: "bazz"} )
			> db.foo.aggregate( [ {$project: { bla: {$divide: [4,2]} } } ] )
			{
				"ok" : 1,
				"result" : [
					{
						"_id" : ObjectId("5368e0011cdcaf5f6a800b03"),
						"bla" : 2
					}
				]
			}

		 */

		Fongo fongo = new Fongo( "fongo" );
		Jongo jongo = new Jongo( fongo.getMongo().getDB( "myDb" ) );
		MongoCollection collection = jongo.getCollection( "foo" );

		collection.insert( "{bar: 'bazz'}" );

		String result = collection
				.aggregate( "{ $project: { bla: {$divide: [4,2]} } }" )
				.map( r -> JSONSerializers.getStrict().serialize( r ) )
				.stream()
				.collect( joining( "," ) );

		System.out.println( result ); // { "_id" : { "$oid" : "5368e0f3cf5a47d5a22d7b75"}}
	}
}