Spring Data JPA

您需要

Specification

public class EntitySpecifications {    public static Specification<Entity> firstIdEquals(Optional<Long> firstId) {// or Long firstId. It is better to avoid Optional method parameters.        return (root, query, builder) ->  firstId.isPresent() ? // or firstId != null if you use Long method parameter builder.equal(root.get("firstId"), firstId.get()) : builder.conjunction(); // to ignore this clause    }    public static Specification<Entity> secondIdEquals(Optional<Long> secondId) {        return (root, query, builder) ->  secondId.isPresent() ?  builder.equal(root.get("secondId"), secondId.get()) : builder.conjunction(); // to ignore this clause    }}

然后你

EntityRepository

JpaSpecificationExecutor

@Repositorypublic interface EntityRepository     extends JpaRepository<Entity, Long>, JpaSpecificationExecutor<Entity> {}

用法：

@Servicepublic class EntityService {    @Autowired    EntityRepository repository;    public List<Entity> getEntities(Optional<Long> firstId, Optional<Long> secondId) {        Specification<Entity> spec =  Specifications.where(EntitySpecifications.firstIdEquals(firstId)) //Spring Data JPA 2.0: use Specification.where    .and(EntitySpecifications.secondIdEquals(secondId));        return repository.findAll(spec); }}