RatingColumnInitializer.java

public class RatingColumnInitializer implements ColumnInitializer<RatingDto> {
    @Override
    public void initializeColumns(CellTable<RatingDto> table) {
        initIdColumn(table);
        initCarColumn(table);
        initRatingColumn(table);
    }

    private void initIdColumn(CellTable<RatingDto> table) {
        Column<RatingDto, Number> idColumn = new Column<RatingDto, Number>(new NumberCell()) {
            @Override
            public Long getValue(RatingDto ratingDto) {
                return ratingDto.getId();
            }
        };

        table.addColumn(idColumn, "ID");
    }

    private void initCarColumn(CellTable<RatingDto> table) {
        Column<RatingDto, String> carColumn = new Column<RatingDto, String>(new TextCell()) {
            @Override
            public String getValue(RatingDto ratingDto) {
                return ratingDto.toString();
            }
        };

        table.addColumn(carColumn, "Car");
    }

    private void initRatingColumn(CellTable<RatingDto> table) {
        Column<RatingDto, Number> ratingColumn = new Column<RatingDto, Number>(new NumberCell()) {
            @Override
            public Number getValue(RatingDto ratingDto) {
                return ratingDto.getRating();
            }
        };

        table.addColumn(ratingColumn, "Rating");
    }
}