Dynamic Queries in Spring Data JPA

Question

I am looking for a solution to dynamically build queries using Spring Data JPA. I have a GameController which has a RESTful service endpoint /games which takes 4 optional pa

Answer 1

I would say that using QueryDSL is one way of doing what you want.

For example I have a repository defined as below:

public interface UserRepository extends PagingAndSortingRepository, QueryDslPredicateExecutor {

    public Page findAll(Predicate predicate, Pageable p);
}

I can call this method with any combination of parameters, like below:

public class UserRepositoryTest{

    @Autowired
    private UserRepository userRepository;

    @Test
    public void testFindByGender() {
        List users = userRepository.findAll(QUser.user.gender.eq(Gender.M));
        Assert.assertEquals(4, users.size());

        users = userRepository.findAll(QUser.user.gender.eq(Gender.F));
        Assert.assertEquals(2, users.size());
    }

    @Test
    public void testFindByCity() {

        List users = userRepository.findAll(QUser.user.address.town.eq("Edinburgh"));
        Assert.assertEquals(2, users.size());

        users = userRepository.findAll(QUser.user.address.town.eq("Stirling"));
        Assert.assertEquals(1, users.size());
    }

    @Test
    public void testFindByGenderAndCity() {
        List users = userRepository.findAll(QUser.user.address.town.eq("Glasgow").and(QUser.user.gender.eq(Gender.M)));
        Assert.assertEquals(2, users.size());

        users = userRepository.findAll(QUser.user.address.town.eq("Glasgow").and(QUser.user.gender.eq(Gender.F)));
        Assert.assertEquals(1, users.size());
    }
}