How do I draw a horizontal line?

[cclement]

What would be the best practice in drawing a horizontal line on an existing chart? Would love to avoid having to create a multi-axis chart as I need to do this for a ton of graphs. Basically I just want to have a few thresholds defined that show if my data is anywhere near hitting that threshold.

So for example CPU usage I want to have a line that exists at 90 (or 90%) which would indicate to the reviewer that perhaps cpu should be upgraded on this particular server if the values were near or above that threshold..

[elizam]

If you're using JFreeCharts, you can write a chart customizer.  The JFreeChart setting is described in a couple of places:

http://stackoverflow.com/questions/9214682/how-to-draw-line-over-a-jfreechart-chart

http://www.jfree.org/phpBB2/viewtopic.php?f=3&t=24865

Chart customizers require you to write a little Java and then apply it to your report.

Here's an example of a simple customizer & how to add it:

http://community.jaspersoft.com/questions/537753/help-use-chart-customizer

and some more info on customizers:

http://community.jaspersoft.com/blog/implementation-and-usage-chart-customizer-classes-customizing-jfreecharts-jasperreports