How to create mongodb collection in spring boot without using pojo class?

Question

I have a spring boot app with a MongoDB connection. On using the POJO/Model class with @Document(Collection = "CompanyDetails"), it successfully creates the collection in MongoDB after "POSTMAPPING" and the result goes inside the CompanyDetails collection as expected.

I have used controller, service, repository, and used the Map<String, Object> in parenthesis of the repository rather than using POJO class.

Controller:

@PostMapping("/addRecords")
public Map<String, Object> addCompanyDetails(@RequestBody Map<String, Object> companyDetails) {
    return companyDetailsService.addCompanyDetails(companyDetails);
}

Service:

@Service
public class CompanyDetailsService {

@Autowired
CompanyDetailsRepository companyDetailsRepository;

public Map<String, Object> addCompanyDetails(Map<String, Object> companyDetails) {
        return companyDetailsRepository.insert(companyDetails);
        
    }
}

Repository:

@Repository
public interface CompanyDetailsRepository extends MongoRepository<Map<String, Object>, String> {}

My requirement is to create a collection without a POJO class. Because, the fields are not fixed(while inserting records). So, I can't declare fields in the POJO class & generate a getter setter.

As I'm not using the POJO class, when I POST record, it creates a collection with the name "map" & insert records inside that. But, expected was to create "CompanyDetails" collection & store data inside that.

Answer 1

Yes, people using MongoDB faced this issue as MongoDB is a schemaless database and creating POJO will be difficult. So, here is the solution for such use-cases.

Firstly, you can use the MongoClient to connect with your database. Check out this document for your reference: Connect to MongoDB

Secondly, you can create databases and collections using that `mongoClient object. Check out this document for your reference Create database and collection

Finally, you can use some generic objects like HashMap or BasicDBObject to perform your CRUD operation