I need a function that will be filter parameters and build query. I have 4 parameters therefore if I would try to implement query for each condition I would have to write 16 (2^4) implementations - it's not good idea.
I try to improve my code with interface Specification from Spring Data JPA but I cannot create conjunction of predicates.
Implementation of Specification interface :
public class UserSpecification implements Specification { private final UserSearchCriteria criteria; public UserSpecification(UserSearchCriteria criteria) { this.criteria = criteria; } @Override public Predicate toPredicate(Root root, CriteriaQuery> query, CriteriaBuilder builder) { final List predicates = new ArrayList(); if (criteria.getName() != null) { final Predicate name = builder.equal(root.get("name"), criteria.getName()); predicates.add(name); } else if (criteria.getSurname() != null) { final Predicate surname = builder.equal(root.get("surname"), criteria.getSurname()); predicates.add(surname); } else if (criteria.getCity() != null) { final Predicate city = builder.equal(root.get("city"), criteria.getCity()); predicates.add(city); } else if (criteria.getCountry() != null) { final Predicate country = builder.equal(root.get("country"), criteria.getCountry()); predicates.add(country); } return builder.and(predicates.toArray(new Predicate[predicates.size()])); } } And test doesn't work :
@Test @Sql( scripts = "classpath:sql/specification.sql", executionPhase = Sql.ExecutionPhase.BEFORE_TEST_METHOD ) public void specificationTest() { // given final UserSearchCriteria criteria = UserSearchCriteria.builder() .name("john") .surname("smith") .build(); final UserSpecification specification = new UserSpecification(criteria); // when final List result = userRepository.findAll(specification); userRepository.flush(); // then assertThat(result).hasSize(3); } Before test I insert to database following users:
INSERT INTO users (id, name, surname, city, country) VALUES (1, 'john', 'smith', null, null); INSERT INTO users (id, name, surname, city, country) VALUES (2, 'john', 'smith', null, null); INSERT INTO users (id, name, surname, city, country) VALUES (3, 'john', 'smith', null, null); INSERT INTO users (id, name, surname, city, country) VALUES (4, 'john', 'abc', null, null); INSERT INTO users (id, name, surname, city, country) VALUES (5, 'abcd', 'abc', null, null); INSERT INTO users (id, name, surname, city, country) VALUES (6, 'abcd', 'abc', null, null); And as a result I get first four rows. Repository matches only first parameter "name" and doesn't match "surname". What is the cause?
(UserSearchCriteria has the same fields as User: name, surname, city, country).