Spring Data Mongodb Bulk Operation Example

Question

Can some one please point me a complete example of Spring Data Mongodb DB bulk operation example.

I am trying to switch to bulk updates using spring data mongodb. Not able to find a good example.

Thank you.

Answer 1

BulkOprations in Spring data mongodb uses bulkWrite() from mongodb.
From mongoDB documentation ->

So When you want to update many entities with different updated in one query you can do that via this bulkOps.

Let us see an example eventhough it may not be an perfect one. Lets consider you have an Employee Collection with employees working in a company. Now After appraisal there will be change in salary for all the employees, and each employee salary change will be different and let's pretend there is no percentage wise hike involved and if you want to update the changes in one go you can use bulkOps.

import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.mongodb.core.BulkOperations;
import org.springframework.data.mongodb.core.MongoTemplate;
import org.springframework.data.mongodb.core.query.Query;
import org.springframework.data.mongodb.core.query.Update;
import org.springframework.data.util.Pair;

public class Example {
    @Autowired
    MongoTemplate mongoTemplate;
    public int bulkUpdateEmployee(List<Pair<Query, Update>> updates){
        return mongoTemplate.bulkOps(BulkOperations.BulkMode.UNORDERED,"employees",Employee.class).updateMulti(updates).execute().getModifiedCount();
    }
}

--------------Here we can prepare the pair of query and update from ------- -------for each employee-> ---"query" - id of employee is blabla ---"update"- set salary to xxx

Answer 2

Sharing the code for bulk operations which worked for me

BulkOperations bulkOps = mongoTemplate.bulkOps(BulkMode.UNORDERED, Person.class);
for(Person person : personList) {
    Query query = new Query().addCriteria(new Criteria("id").is(person.getId()));
    Update update = new Update().set("address", "new Address as per requirement");
    bulkOps.updateOne(query, update);
}
BulkWriteResult results = bulkOps.execute();