How to return values of only one parameter in GetMapping?

I have an API. How to return the values of only one column (name) from the database? Request code in the controller:

@RestController
public class PURController {
    @Autowired
    private PURRepository purRepository;
@CrossOrigin()
    @GetMapping("/purs/getname/{device}")
    public ResponseEntity<ArrayList<PUR>> getPurName(@PathVariable(value = "device") String device){
         ArrayList<PUR> pur = purRepository.findAllByDevice(device);
        return ResponseEntity.ok().body(pur);
    }

In this case, all rows found by the "device" field are returned. Also I have a method in PUR.java:

public String getName() {
        return name;
    }

How can it all be connected?

Also: my repository class:

@Repository
public interface PURRepository extends JpaRepository<PUR, Long> {
    ArrayList<PUR> findAllByDevice(String device);
    Optional<PUR> findByDevice(String device);}

Response now:

[{"id":48,"name":"6-PRN.00-00.01","quantity":3,"device":"6-PRN.01-01.000"},{"id":49,"name":"6-PRN.00-00.02","quantity":7,"device":"6-PRN.01-01.000"},{"id":50,"name":"6-PRN.00-00.03","quantity":4,"device":"6-PRN.01-01.000"}]

Response i want:

[{6-PRN.00-00.01},{6-PRN.00-00.02},{6-PRN.00-00.03}]

Solution

You don't need to use stream. You can solve it easily:

  @Query(value = "SELECT p.name FROM PUR p where p.device= :device", nativeQuery = true)
  List<String> findAllNamesByDevice(@Param("device") String device);