Katharsis + SpringBoot + Postgresql

[tr3mendous]

Hello,
I can't understand how to connect my RestController to db, how i can send queries to db and get it's response?
I tried some ugly ways like this

    @RequestMapping(method = GET)
    @ResponseBody
    public ResourceList<TestEntity> getAllEntities() {
        TestEntityRepository repository = new TestEntityRepository();
        for (RegistryEntry entry : resourceRegistry.getResources()) {
             repository = (TestEntityRepository)entry.getResourceRepository(null).getResourceRepository();
        }
        return repository.findAll(new QuerySpec(TestEntity.class));
    }

and others. Could somebody help my with this issue?