Why methods doesn't see values set in constructor? (Spring Boot) - spring

Question

I have a class AuthorizationService like this:
#Service
public class AuthorizationService {
private final String code;
private final String client_id;
private final String redirect_uri;
private final String scope;
private final String show_dialog;
#Autowired
public AuthorizationService(
#Value("${spotify-property.response_type}") String code,
#Value("${spotify-property.client_id}") String client_id,
#Value("${spotify-property.redirect_uri}") String redirect_uri,
#Value("${spotify-property.scope}") String scope,
#Value("${spotify-property.redirect_uri}") String show_dialog) {
this.code = code;
this.client_id = client_id;
this.redirect_uri = redirect_uri;
this.scope = scope;
this.show_dialog = show_dialog;
System.out.println(code); //works
}
public ResponseEntity<HttpHeaders> getSpotifyRedirectionCode() {
HttpHeaders headers = new HttpHeaders();
System.out.println(client_id); //doesn't work
System.out.println(this.code); //does not work either
System.out.println(redirect_uri);
System.out.println(scope);
System.out.println(show_dialog);
//more code doesn't matter
return new ResponseEntity<>(headers, HttpStatus.TEMPORARY_REDIRECT);
}
Why these variables are ok in constructor but in methods are null, how to set them in correct way? Also
#Value("${spotify-property.response_type}")
private final String code;
does not work either.

Answer 1

Your class fields are final so get instantiated without your configuration values.
You can either use the constructor as you have before, or remove the final from your fields.

Answer 2

I'm not sure if my answer is 100% correct. But I believe that you cannot change final variables. The right way would be to remove the final keyword and keep the #Value annotations on the fields and the you don't have to use it in the constructor.
#Service
#RequiredArgsConstructor
public class AuthorizationService {
#Value("${spotify-property.response_type}")
private String code;
#Value("${spotify-property.client_id}")
private String client_id;
#Value("${spotify-property.redirect_uri}")
private String redirect_uri;
#Value("${spotify-property.scope}")
private String scope;
#Value("${spotify-property.redirect_uri}")
private String show_dialog;
public ResponseEntity<HttpHeaders> getSpotifyRedirectionCode() {
HttpHeaders headers = new HttpHeaders();
System.out.println(client_id); //works
System.out.println(this.code); //works too
System.out.println(this.redirect_uri);
System.out.println(this.scope);
System.out.println(this.show_dialog);
//more code doesn't matter
return new ResponseEntity<>(headers, HttpStatus.TEMPORARY_REDIRECT);
} }