How to make JavaFX Chart NumberAxis only show Inte

Question

I'm trying to create a chart who's yAxis is designed to show number of employee number, so it must only show whole numbers.
But I found it's not that easy as I already tried to yAxis.setTickUnit(1) but it won't work when the values are small(etc. the max value is 3, it'll still show 0.5,1.5..., I only want tick value like 1,2,3,4..)
How Could I to achieve this?

According to @jewelsea 's answer, I tried this(In javafx 2.2 jdk7)

class IntegerStringConverter extends StringConverter<Number>{

    public IntegerStringConverter() {
    }

    @Override
    public String toString(Number object) {
        if(object.intValue()!=object.doubleValue())
            return "";
        return ""+(object.intValue());
    }

    @Override
    public Number fromString(String string) {
        Number val = Double.parseDouble(string);
        return val.intValue();
    }
}  

It's result is kind of acceptable. Double value's are gone, but there ticks are still there.

Answer 1

Set a tickLabelFormatter on the axis.

Answer 2

You can set the NumberAxis(double lowerBound, double upperBound, double tickUnit) values by using the constructor. This works fine for JaxaFX 8, in case people like me are still looking for this.

Source: https://docs.oracle.com/javase/8/javafx/api/javafx/scene/chart/NumberAxis.html