Missing CrudRepository#findOne method

Question

I am using Spring 5 in my project. Until today there was available method CrudRepository#findOne.

But after downloading latest snapshot it suddenly disappeared! Is t

Answer 1

Please see DATACMNS-944 which is associated to this commit which has the following renames

╔═════════════════════╦═══════════════════════╗
║      Old name       ║       New name        ║
╠═════════════════════╬═══════════════════════╣
║ findOne(…)          ║ findById(…)           ║
╠═════════════════════╬═══════════════════════╣
║ save(Iterable)      ║ saveAll(Iterable)     ║
╠═════════════════════╬═══════════════════════╣
║ findAll(Iterable)   ║ findAllById(…)        ║
╠═════════════════════╬═══════════════════════╣
║ delete(ID)          ║ deleteById(ID)        ║
╠═════════════════════╬═══════════════════════╣
║ delete(Iterable)    ║ deleteAll(Iterable)   ║
╠═════════════════════╬═══════════════════════╣
║ exists()            ║ existsById(…)         ║
╚═════════════════════╩═══════════════════════╝

Answer 2

An other way more. Add a @Query. Even if I would prefer to consume the Optional:

@Repository
public interface AccountRepository extends JpaRepository<AccountEntity, Long> {

    @Query("select a from AccountEntity a where a.id=?1")
    public AccountEntity findOne(Long id);

Answer 3

We had many hundreds of usages of the old findOne() method. Rather than embark on a mammoth refactor, we ended up creating the following intermediary interface and had our repositories extend it instead of extending JpaRepository directly

@NoRepositoryBean
public interface BaseJpaRepository<T, ID> extends JpaRepository<T, ID> { 
    default T findOne(ID id) { 
        return (T) findById(id).orElse(null); 
    } 
} 

Answer 4

Note that findById is not an exact replacement for findOne, it returns an Optional instead of null.

Being not very familiar with new java things it took me a little while to figure out, but this turns the findById behavior into the findOne one:

return rep.findById(id).orElse(null);

Answer 5

A pragmatic transform

Old way:

Entity aThing = repository.findOne(1L);

New way:

Optional<Entity> aThing = repository.findById(1L);