为什么Sonar说没有可覆盖的方法调用时，构造函数调用Overridable方法？

Question

我在SONAR中遇到以下代码问题。但是该类实现了BaseDatabase接口，其方法不是从构造函数调用的。

public class DerbyDatabaseHelper implements BaseDatabase {

    private static boolean isInitializationDone;
    private static Connection connection;
    private static final Logger LOGGER = Logger
            .getLogger(DerbyDatabaseHelper.class);

    /**
     * @param connection
     *            the connection to set
     */
    private static void setConnection(Connection connection) {
        DerbyDatabaseHelper.connection = connection;
    }

    public DerbyDatabaseHelper() {
        deleteDerbyFolder(new File("NewDB"));
        if (!isInitializationDone) {
            initializeDB();
            setInitializationDone(true);
        }
    }

    /**
     * This method initializes the Derby Schema.
     */
    private void initializeDB() {
        try {
            // ScriptRunner of Apache ibatis to execute the sql file for
            // creating database schema in DerbyDB .
            new ScriptRunner(getConnection())
                    .runScript(new InputStreamReader(new FileInputStream(
                            ConfigReader.getValue("schemaFilePath")), Charset
                            .defaultCharset()));
        } catch (Exception e) {
            LOGGER.error(
                    "Exception occurred during Initialization of DB.  Exception details :: ",
                    e);
        } finally {
            closeConnection();
        }

    }

    /**
     * This method is used to get the derby database connection object
     */
    @Override
    public Connection getConnection() {
        if (connection == null) {
            try {
                loadDerbyClass();
                // Create jdbc Connection
                setConnection(DriverManager.getConnection(ConfigReader
                        .getValue("initialUrl")
                        + ConfigReader.getValue("dbName")
                        + ConfigReader.getValue("createDb")));

            } catch (SQLException e) {
                LOGGER.error(
                        "Exception occurred during creating connection.  Exception details :: ",
                        e);
            }
        }
        return connection;
    }

    /**
     * This method is used to close the acquired derby database connection
     * object.
     */
    @Override
    public void closeConnection() {
        if (connection != null) {
            try {
                connection.close();
            } catch (Exception e) {
                LOGGER.error(
                        "Exception occurred during closing connection.  Exception details :: ",
                        e);
            }
        }
    }

和界面

public interface BaseDatabase {

    Connection getConnection();

    void closeConnection();

}

正如我们所看到的，没有从构造函数调用的覆盖方法，声纳无法解释该问题。