BarRenderer barrenderer = (BarRenderer)categoryplot.getRenderer();
barrenderer.setDrawBarOutline(false);
GradientPaint gradientpaint = new GradientPaint(0.0F, 0.0F, Color.blue, 0.0F, 0.0F, new Color(0, 0, 64));
GradientPaint gradientpaint1 = new GradientPaint(0.0F, 0.0F, Color.green, 0.0F, 0.0F, new Color(0, 64, 0));
barrenderer.setSeriesPaint(0, gradientpaint);
barrenderer.setSeriesPaint(1, gradientpaint1);
> That will set the Bar's Gradient, not the
> CategoryPlot object.
So you need something likeCategoryPlot categoryPlot = jfreechart.getCategoryPlot();
GradientPaint gradientPaint = new GradientPaint(0.0F, 0.0F, Color.BLUE, 10.0F, 10.0F, Color.RED, true);
categoryPlot.setBackgroundPaint(gradientPaint);