Trendline on a bar chart

I am trying to add a trendline (going up or down) on a bar chart. Does anyone have any idea on how to do this?

I used addRangeMarker to add a horizontal line, but I couldn’t get to make the line to have a up or down trend.


You might have better luck with a CategoryLineAnnotation: CategoryLineAnnotation (JFreeChart 1.5.0 API)