Interval Marker | Set Goal or Target line in Bar Chart
Interval Marker is a special feature that allows you set targets or reference point for your bar or line charts.
Here is a basic bar chart

To add a reference line or interval marker as below

Use the following code for the javascript
//import the necessary classes
import org.jfree.*;
import org.jfree.chart.axis.CategoryAxis;
//import org.jfree.chart.axis.CategoryLabelPositions;
import org.jfree.chart.axis.NumberAxis;
//import org.jfree.chart.labels.CategoryItemLabelGenerator;
//import org.jfree.chart.labels.StandardCategoryItemLabelGenerator;
import org.jfree.chart.plot.CategoryPlot;
import org.jfree.chart.plot.PiePlot3D;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.renderer.category.BarRenderer;
import org.jfree.chart.renderer.category.BarRenderer3D;
//import org.jfree.chart.renderer.category.CategoryItemRenderer;
//import org.jfree.chart.renderer.category.LineAndShapeRenderer;
import org.jfree.ui.GradientPaintTransformType;
import org.jfree.ui.StandardGradientPaintTransformer;
import org.jfree.chart.plot.IntervalMarker;
import org.jfree.ui.Layer;import org.jfree.ui.RectangleAnchor;
import org.jfree.ui.RefineryUtilities;
import org.jfree.ui.TextAnchor;BarRenderer barRenderer = (BarRenderer)plot.getRenderer();
barRenderer.setDrawBarOutline(false);
IntervalMarker target = new IntervalMarker(70000,75000);
target.setLabelFont(new Font(”SansSerif”, Font.ITALIC, 11));
target.setLabelAnchor(RectangleAnchor.LEFT);
target.setLabelTextAnchor(TextAnchor.CENTER_LEFT);
plot.addRangeMarker(target, Layer.BACKGROUND);