java - Spring CrudRepository .orElseThrow() -

java - Spring CrudRepository .orElseThrow() -

what proper way throw exception if database query returns empty? i'm trying utilize .orelsethrow() method won't compile :

meeting meeting = meetingrepository.findbymeetingid(meetingid).orelsethrow(new meetingdoesnotexistexception(meetingid));

the compiler saying :

"he method orelsethrow(supplier) in type optional not applicable arguments (meetingrestcontroller.meetingdoesnotexistexception)

is possible lambda expressions?

crudrepository :

import java.util.optional; import org.springframework.data.repository.crudrepository; public interface meetingrepository extends crudrepository<meeting, long>{ optional<meeting> findbymeetingid(long id); }

exception :

@responsestatus(httpstatus.conflict) // 409 class meetingdoesnotexistexception extends runtimeexception{ public meetingdoesnotexistexception(long meetingid){ super("meeting " + meetingid + " not exist."); } }

try passing lambda look of type supplier<meetingdoesnotexistexception> :

meeting meeting = meetingrepository.findbymeetingid(meetingid) .orelsethrow(() -> new meetingdoesnotexistexception(meetingid));

java spring java-8 crud spring-boot