= Spring Data REST URI customizations
This example shows how to customize which property of the domain type shall be used to create URIs for item resources. This is achieved by implementing an `EntityLookup` and declaring it as Spring bean:
[source, java]
----
@Component
@RequiredArgsConstructor(onConstructor = @__(@Autowired) )
public class UserEntityLookup extends EntityLookupSupport<User> {
private final @NonNull UserRepository repository;
@Override
public Serializable getResourceIdentifier(User entity) {
return entity.getUsername();
}
@Override
public Object lookupEntity(Serializable id) {
return repository.findByUsername(id.toString());
}
}
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As you can see the customization consists of two methods that need to be symmetric in their functionality. `getResourceIdentifier(…)` returns the property that's supposed to be used in the URI while `lookupEntity(…)` uses the value to lookup an entity via a query method for exactly that property.
