Spring Data optional parameter in query method

I don't believe you'll be able to do that with the method name approach to query definition. From the documentation (reference):

Although getting a query derived from the method name is quite convenient, one might face the situation in which either the method name parser does not support the keyword one wants to use or the method name would get unnecessarily ugly. So you can either use JPA named queries through a naming convention (see Using JPA NamedQueries for more information) or rather annotate your query method with @Query

I think you have that situation here, so the answer below uses the @Query annotation approach, which is almost as convenient as the method name approach (reference).

    @Query("select foo from Foo foo where foo.bar = :bar and "
        + "(:goo is null or foo.goo = :goo)")
    public List<Foo> findByBarAndOptionalGoo(
        @Param("bar") Bar bar, 
        @Param("goo") Goo goo);

Complementing the answer of @chaserb, I personally would add the parameter as a Java8 Optional type to make it explicit in the signature of the method the semantics that is an optional filter.

@Query("select foo from Foo foo where foo.bar = :bar and "
   + "(:goo is null or foo.goo = :goo)")
public List<Foo> findByBarAndOptionalGoo(
     @Param("bar") Bar bar, 
     @Param("goo") Optional<Goo> goo);

So many great answers already, but I specifically implemented this using the answer from @Pankaj Garg (Using the Spring Specification API). There are a few use cases I am adding to my answer

• 4 parameters that may or may not be null.
• Paginated response from the repository.
• Filtering by a field in a nested object.
• Ordering by a specific field.

First I create a couple of entities, specifically Ticket, Movie and Customer. Nothing fancy here:

import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;

import javax.persistence.*;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;
import java.io.Serializable;
import java.math.BigDecimal;
import java.util.Date;
import java.util.UUID;

@Entity
@Table(name = "ticket", schema = "public")
@Data
@NoArgsConstructor
@AllArgsConstructor
@Builder(toBuilder = true)
public class Ticket implements Serializable  {

    @Id
    @Basic(optional = false)
    @NotNull
    @Column(name = "id", nullable = false)
    private UUID id;

    @JoinColumn(name = "movie_id", referencedColumnName = "id", nullable = false)
    @ManyToOne(fetch = FetchType.EAGER)
    private Movie movie;

    @JoinColumn(name = "customer_id", referencedColumnName = "id", nullable = false)
    @ManyToOne(fetch = FetchType.EAGER)
    private Customer customer;

    @Column(name = "booking_date")
    @Temporal(TemporalType.TIMESTAMP)
    private Date bookingDate;
}

Movie:

import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;

import javax.persistence.*;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;
import java.io.Serializable;

@Entity
@Table(name = "movie", schema = "public")
@Data
@NoArgsConstructor
@AllArgsConstructor
@Builder(toBuilder = true)
public class Movie implements Serializable {

    @Id
    @Basic(optional = false)
    @NotNull
    @Column(name = "id", nullable = false)
    private UUID id;

    @Basic(optional = false)
    @NotNull
    @Size(max = 100)
    @Column(name = "movie_name", nullable = false, length = 100)
    private String movieName;
}

Customer:

import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;

import javax.persistence.*;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;
import java.io.Serializable;

@Entity
@Table(name = "customer", schema = "public")
@Data
@NoArgsConstructor
@AllArgsConstructor
@Builder(toBuilder = true)
public class Customer implements Serializable {

    @Id
    @Basic(optional = false)
    @NotNull
    @Column(name = "id", nullable = false)
    private UUID id;

    @Basic(optional = false)
    @NotNull
    @Size(max = 100)
    @Column(name = "full_name", nullable = false, length = 100)
    private String fullName;
}

Then I create a class with fields for the parameters I wish to filter by:

import lombok.AllArgsConstructor;
import lombok.Data;

import java.util.Date;
import java.util.UUID;

@Data
@AllArgsConstructor
public class TicketFilterParam {
    private UUID movieId;
    private UUID customerId;
    private Date start;
    private Date end;
}

Next I create a class to generate a Specification based on the filter parameters. Note the way nested objects are accessed, as well as the way ordering is added to the query.

import org.springframework.data.jpa.domain.Specification;

import javax.persistence.criteria.Predicate;
import java.util.ArrayList;
import java.util.List;
import java.util.UUID;

public class TicketSpecifications {
    public static Specification<Ticket> getFilteredTickets(TicketFilterParam params) {
        return (root, criteriaQuery, criteriaBuilder) -> {
            List<Predicate> predicates = new ArrayList<>();

            if (params.getMovieId() != null) {
                predicates.add(criteriaBuilder.equal(root.get("movie").<UUID> get("id"), params.getMarketerId()));
            }

            if (params.getCustomerId() != null) {
                predicates.add(criteriaBuilder.equal(root.get("customer").<UUID> get("id"), params.getDepotId()));
            }

            if (params.getStart() != null && params.getEnd() != null) {
                predicates.add(criteriaBuilder.between(root.get("bookingDate"), params.getStart(), params.getEnd()));
            }

            criteriaQuery.orderBy(criteriaBuilder.desc(root.get("bookingDate")));

            return criteriaBuilder.and(predicates.toArray(new Predicate[0]));
        };
    }
}

Next I define the Repository interface. This would have not only JpaRepository, but also JpaSpecificationExecutor:

import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.JpaSpecificationExecutor;
import org.springframework.stereotype.Repository;

@Repository
public interface TicketRepository extends JpaRepository<Ticket, UUID>, JpaSpecificationExecutor<Ticket> {
}

Finally, in some service class, I obtain results like this:

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.jpa.domain.Specification;
import org.springframework.stereotype.Service;

@Service
public class TicketService {
    @Autowired
    private TicketRepository ticketRepository;

    public Page<Ticket> getTickets(TicketFilterParam params, PageRequest pageRequest) {
        Specification<Ticket> specification = TicketSpecifications.getFilteredTickets(params);
        return ticketRepository.findAll(specification, pageRequest);
    }
}

PageRequest and TicketFilterParam would probably be obtained from some parameters and values on a rest endpoint.

You can use JpaSpecificationExecutor //import org.springframework.data.jpa.repository.JpaSpecificationExecutor;

Step 1: Implement JpaSpecificationExecutor in your JPA Repository

Ex:

public interface TicketRepo extends JpaRepository<Ticket, Long>, JpaSpecificationExecutor<Ticket> {

Step 2 Now to fetch tickets based on optional parameters you can build Specification query using CriteriaBuilder

Ex:

public Specification<Ticket> getTicketQuery(Integer domainId, Calendar startDate, Calendar endDate, Integer gameId, Integer drawId) {
    return (root, query, criteriaBuilder) -> {
        List<Predicate> predicates = new ArrayList<>();

        predicates.add(criteriaBuilder.equal(root.get("domainId"), domainId));
        predicates.add(criteriaBuilder.greaterThanOrEqualTo(root.get("createdAt"), startDate));
        predicates.add(criteriaBuilder.lessThanOrEqualTo(root.get("createdAt"), endDate));

        if (gameId != null) {
            predicates.add(criteriaBuilder.equal(root.get("gameId"), gameId));
        }

        return criteriaBuilder.and(predicates.toArray(new Predicate[0]));
    };
}

Step 3: Pass the Specification instance to jpaRepo.findAll(specification), it will return you the list of your entity object (Tickets here in the running example)

ticketRepo.findAll(specification); // Pass output of function in step 2 to findAll

You could code this yourself in just a few lines:

List<Foo> findByBarAndOptionalGoo(Bar bar, Goo goo) {
   return (goo == null) ? this.findByBar(bar) : this.findByBarAndGoo(bar, goo);
}

Otherwise, I don't know if Spring-Data supports this out of the box.

It is too late too answer, but for anyone who looks for a solution yet there is a more simple way as below, I have faced the same issue and finally could find this solution that looks like very simple and efficient than the others to me:

my Controller Class:

@RestController
@RequestMapping("/order")
public class OrderController {

    private final IOrderService service;

    public OrderController(IOrderService service) {
        this.service = service;
    }

    @RequestMapping(value = "/{username}/", method = RequestMethod.GET)
    public ResponseEntity<ListResponse<UserOrdersResponse>> getUserOrders(
            @RequestHeader Map<String, String> requestHeaders,
            @RequestParam(required=false) Long id,
            @RequestParam(required=false) Long flags,
            @RequestParam(required=true) Long offset,
            @RequestParam(required=true) Long length) {
        // Return successful response
        return new ResponseEntity<>(service.getUserOrders(requestDTO), HttpStatus.OK);
    }
}

As you can see, I have Username as @PathVariable and length and offset which are my required parameters, but I accept id and flags for filtering search result, so they are my optional parameters and are not necessary for calling the REST service.

my Repository interface:

@Query("select new com.ada.bourse.wealth.services.models.response.UserOrdersResponse(FIELDS ARE DELETED TO BECOME MORE READABLE)" +
        " from User u join Orders o on u.id = o.user.id where u.userName = :username" +
        " and (:orderId is null or o.id = :orderId) and (:flag is null or o.flags = :flag)")
Page<UserOrdersResponse> findUsersOrders(String username, Long orderId, Long flag, Pageable page);

And that's it, you can see that I checked my optional arguments with (:orderId is null or o.id = :orderId) and (:flag is null or o.flags = :flag) and I think it needs to be emphasized that I checked my argument with is null condition not my columns data, so if client send Id and flags parameters for me I will filter the Result with them otherwise I just query with username which was my @PathVariable.