Spring Data – Add custom method to Repository
In this article, we will show you how to add a custom method to Spring Data JPA CrudRepository
and MongoDB MongoRepository
1. CrudRepository
1.1 Review a CustomerRepository
, we will add a custom method to this repository.
package com.mkyong.dao;
import com.mkyong.model.Customer;
import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.CrudRepository;
import org.springframework.data.repository.query.Param;
import java.util.Date;
import java.util.List;
import java.util.stream.Stream;
public interface CustomerRepository extends CrudRepository<Customer, Long> {
List<Customer> findByEmail(String email);
@Query("select c from Customer c where c.email = :email")
Stream<Customer> findByEmailReturnStream(@Param("email") String email);
// I have a complicated logic, no idea how to implement with @Query ...
}
1.2 Create an interface.
package com.mkyong.dao;
import com.mkyong.model.Customer;
import java.util.List;
public interface CustomerRepositoryCustomAbc {
List<Customer> findByAVeryComplicatedQuery(Long id, String name, String address);
}
1.3 For implementation class, the class name is very strict, you need to follow the “core repository interface + Impl” pattern. Failed to follow this pattern will cause the “Spring property unable to find” error message.
package com.mkyong.dao;
import com.mkyong.model.Customer;
import java.util.List;
public class CustomerRepositoryImpl implements CustomerRepositoryCustomAbc {
@Override
public List<Customer> findByAVeryComplicatedQuery(Long id, String name, String address) {
//...
}
}
1.4 Update CustomerRepository
to extend the new CustomerRepositoryCustomAbc
interface.
package com.mkyong.dao;
import com.mkyong.model.Customer;
import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.CrudRepository;
import org.springframework.data.repository.query.Param;
import java.util.Date;
import java.util.List;
import java.util.stream.Stream;
public interface CustomerRepository extends CrudRepository<Customer, Long>, CustomerRepositoryCustomAbc{
//...
}
Done.
2. MongoRepository
2.1 Another example to add a new “update a particular field” method to MongoRepository
package com.mkyong.domain;
import org.springframework.data.mongodb.repository.MongoRepository;
import org.springframework.data.mongodb.repository.Query;
import java.util.List;
public interface DomainRepository extends MongoRepository<Domain, Long> {
Domain findByDomainAndIP(String domain, String ip);
@Query("{domain: { $regex: ?0 } })")
List<Domain> findCustomByRegExDomain(String domain);
//how to update a particular field? save() is not what I want.
}
2.2 Custome interface.
package com.mkyong.domain;
public interface DomainRepositoryCustomAnyName {
int updateDomainDisplayFlagOnly(String domain, boolean flag);
}
2.3 Custom implementation.
package com.mkyong.domain;
import com.mongodb.WriteResult;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.mongodb.core.MongoTemplate;
import org.springframework.data.mongodb.core.query.Criteria;
import org.springframework.data.mongodb.core.query.Query;
import org.springframework.data.mongodb.core.query.Update;
//Impl postfix of the name on it compared to the core repository interface
public class DomainRepositoryImpl implements DomainRepositoryCustomAnyName {
@Autowired
MongoTemplate mongoTemplate;
@Override
public int updateDomainDisplayFlagOnly(String domain, boolean flag) {
Query query = new Query(Criteria.where("domain").is(domain));
Update update = new Update();
update.set("display", flag);
WriteResult result = mongoTemplate.updateFirst(query, update, Domain.class);
if(result!=null)
return result.getN();
else
return 0;
}
}
2.4 Update DomainRepository
to extend the new custom interface – DomainRepositoryCustomAnyName
package com.mkyong.domain;
import org.springframework.data.mongodb.repository.MongoRepository;
import org.springframework.data.mongodb.repository.Query;
import java.util.List;
public interface DomainRepository extends MongoRepository<Domain, Long>, DomainRepositoryCustomAnyName {
//...
}
Done.
Hello Mr Mkyong, I have some difficulty to test this kind of custom implementation with JUnit Test, I got a NoSuchElementExeption. Is there anything I would be doing wrong?
I too face this same issue. Have you found any solutions ?
How can i query if i have a mongoDB structure as follows: countries –> states –> particularState.
query.addCriteria(Criteria.where(“countries.states.StateID”).is(123));
How to deal with three level nested attributes.
I need Spring to auto-create implementations out of my @Repository interfaces, but I need to alter the delete method.
And this seems like exactly what I was looking for.
Thank you very much, sir 🙂