How to add custom method to Spring Data JPA

You need to create a separate interface for your custom methods:

public interface AccountRepository     extends JpaRepository<Account, Long>, AccountRepositoryCustom { ... }public interface AccountRepositoryCustom {    public void customMethod();}

and provide an implementation class for that interface:

public class AccountRepositoryImpl implements AccountRepositoryCustom {    @Autowired    @Lazy    AccountRepository accountRepository;  /* Optional - if you need it */    public void customMethod() { ... }}

See also:

• 4.6 Custom Implementations for Spring Data Repositories

• Note that the naming scheme has changed between versions. See https://stackoverflow.com/a/52624752/66686 for details.

In addition to axtavt's answer, don't forget you can inject Entity Manager in your custom implementation if you need it to build your queries:

public class AccountRepositoryImpl implements AccountRepositoryCustom {    @PersistenceContext    private EntityManager em;    public void customMethod() {         ...        em.createQuery(yourCriteria);        ...    }}

The accepted answer works, but has three problems:

• It uses an undocumented Spring Data feature when naming the custom implementation as AccountRepositoryImpl. The documentation clearly states that it has to be called AccountRepositoryCustomImpl, the custom interface name plus Impl
• You cannot use constructor injection, only @Autowired, that are considered bad practice
• You have a circular dependency inside of the custom implementation (that's why you cannot use constructor injection).

I found a way to make it perfect, though not without using another undocumented Spring Data feature:

public interface AccountRepository extends AccountRepositoryBasic,                                           AccountRepositoryCustom { }public interface AccountRepositoryBasic extends JpaRepository<Account, Long>{    // standard Spring Data methods, like findByLogin}public interface AccountRepositoryCustom {    public void customMethod();}public class AccountRepositoryCustomImpl implements AccountRepositoryCustom {    private final AccountRepositoryBasic accountRepositoryBasic;    // constructor-based injection    public AccountRepositoryCustomImpl(        AccountRepositoryBasic accountRepositoryBasic)    {        this.accountRepositoryBasic = accountRepositoryBasic;    }    public void customMethod()     {        // we can call all basic Spring Data methods using        // accountRepositoryBasic    }}