[S1258] False positive on missing constructor for @FXML tag

SonarQube Server / Community Build
1

Sonar and Sonarlint report a false positive [S1258] when the JavaFX @FXML tag is used in the code and nothing is done in the constructor. However, according to the tag documentation:

The @FXML annotation enables an FXMLLoader to inject values defined in an FXML file into references in the controller class.

Classes and enums with private members should have a constructor

Code smell

Major
java:S1258

Non-abstract classes and enums with non-static, private members should explicitly initialize those members, either in a constructor or with a default value.

Versions used:

  • InteliJ: IntelliJ IDEA 2024.1 (Ultimate Edition) Build #IU-241.14494.240
  • SonarQube 9.9.2 (build 77730)
  • SonarLint plugin for InteliJ: 10.5.0.78339
  • JDK 11 (AdoptOpenJDK 11.0.7+10)
  • JavaFX 17.0.6

Minimal code sample to reproduce:

import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.Label;

import java.net.URL;
import java.util.ResourceBundle;

public class Demo implements Initializable
{ //[S1258] SonarLint: Add a constructor to the class, or provide default values.

    @FXML
    private Label label;

    @Override
    public void initialize(URL url, ResourceBundle resourceBundle)
    {}
}
4

Hello @Astella, welcome to the Sonar Community and thank you for reporting this false positive.

You can track the progress with its resolution at [SONARJAVA-5136] - Jira.

Cheers,
Angelo