Fetch only matched array object from a list of available array objects with MongoTemplate and Query API

Question

I have a scenario where i pass a parameters to a collection in MongoDB and fetch only that particular array object serviceType which matched my criteria "serviceType"= Repairs & Fixes.

Collection Sample

"serviceTypes": [
        {
            "serviceType": "Installation/Uninstallation Service",
        },
        {
            "serviceType": "Repairs & Fixes",
        },
        {
            "serviceType": "Electricity Breakdown",
        },
        {
            "serviceType": "Electricity Wiring",
        }
    ]

As per my implementation below, it fetches all the array objects instead of that particular array object. The above collection sample is the actual response for the below code.

import org.springframework.data.mongodb.core.MongoTemplate;
import org.springframework.data.mongodb.core.mapping.Field;
import org.springframework.data.mongodb.core.query.Criteria;
import org.springframework.data.mongodb.core.query.Query;
@Override
public ServiceList findOneByServiceType(String categoryName, String 
serviceType1) {
    // TODO Auto-generated method stub
    Query query = new Query() ;
query.addCriteria(Criteria.where("categoryName").is(categoryName).andOperator(Criteria.where("serviceTypes").elemMatch(Criteria.where("serviceType").is(serviceType1))));
    query.fields().include("serviceTypes.serviceType");
    return (ServiceList) mongoTemplate.findOne(query,ServiceList.class);
}

How to handle this scenario with mongotemplate and Query api of Spring boot Mongo?

Answer 1

You just need to replace this line

query.fields().include("serviceTypes.serviceType");

with the below line

query.fields().include("serviceTypes").position("serviceTypes",1);