JPA fully dynamic and multi level criteria api

Question

I\'m trying to see how I would create a JPA Critera query which allows for fully dynamic filtering with multiple levels.

For example

select * 
from tabl         


        

Answer 1

You need to create a Specification as in the test below. This can be dynamic.

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes=HelloWorldConfig.class)
public class SpecificationTest {

    @Autowired
    private AccountRepository repository;

    @Test
    public void test1() {
        final List<String> names = Arrays.asList(new String[]{"George","Max"});
        Specification<Account> specification = new Specification<Account>() {
            public Predicate toPredicate(Root<Account> root, CriteriaQuery<?> query, CriteriaBuilder builder) {
                List<Predicate> predicates = new ArrayList<Predicate>();
                predicates.add(root.get("name").in(names).not());
                return builder.and(predicates.toArray(new Predicate[predicates.size()]));
            }
        };
        assertNotNull(repository);
        repository.save(makeAccount("Greg", "123456787", "01-02-01"));
        repository.save(makeAccount("George", "123456788", "01-02-02"));
        repository.save(makeAccount("Max", "123456789", "01-02-03"));

        List<Account> accounts = repository.findAll(specification);
        assertEquals(1,accounts.size());
        assertEquals("123456787",accounts.get(0).getAccountNumber());
    }

    private Account makeAccount(String name, String accountNumber, String sortCode) {
        Account account = new Account();
        account.setName(name);
        account.setAccountNumber(accountNumber);
        account.setSort(sortCode);
        return account;
    }
}

Where the repository looks like :

@Repository
public interface AccountRepository extends JpaRepository<Account, Long>, JpaSpecificationExecutor<Account> {
}