[FIXED] Spring Error:(21, 34) java: variable customUriBuilder not initialized in the default constructor

Issue

I have Spring bean

@Component
public class CustomUriBuilder {

    private final String cUrl;
    private final String redirectUri;
    private final String clientId;

    public CustomUriBuilder (@Value("${project.url}") String cUrl,
                          @Value("${project.redirect.url}") String redirectUri, @Value("${project.client-id}") String clientId) {
        this.cUrl= cUrl;
        this.redirectUri = redirectUri;
        this.clientId = clientId;
    }
    //No default constructor
}

I need to inject this bean in another bean

@Component
public class LinksBuilder {
    @Autowired
    private final CustomUriBuilder customUriBuilder ;
    //No constructors
}

But i got compilation error

Error:(21, 34) java: variable customUriBuilder not initialized in the default constructor

At the same time i am injecting LinksBuilder(as final) in another controller without any problems

@RestController
@RequestMapping(produces = "application/json")
public class resourceV4 {

    private final LinksBuilder linksBuilder;
    //No constructors 
    .
}

Why in the first case it gives an error but in the second case it is working fine?

Solution

Since spring 4.3 there is a feature - you can not add Autowired annotation for the final fields injection

You must have a constructor initialization for the final fields. I can not see one for the LinksBuilder and resourceV4. See lombok @RequiredArgsContructor for short.

It is impossible that one class with a final field is compiled ok and without constructor, but another one with an error.

Run other compilers or build ways (terminal gradlew/maven etc) to clarify the situation for you

Answered By - Artem Ptushkin