I'm trying to customize a bar chart. I have implemented a JRChartCustomizer with this snipet code: Code:import org.jfree.chart.JFreeChart; import org.jfree.chart.renderer.category.BarRenderer; import net.sf.jasperreports.engine.JRChart; import net.sf.jasperreports.engine.JRChartCustomizer; public class BarChartCustomizer implements JRChartCustomizer { public void customize(JFreeChart chart, JRChart jasperChart) { BarRenderer renderer = (BarRenderer) chart.getCategoryPlot().getRenderer(); renderer.setMaxBarWidth (0.1); } } But when I execute the report the following error occurs: Code:[code]Filling report... Error filling print... net.sf.jasperreports.engine.JRRuntimeException: BarChartCustomizer at net.sf.jasperreports.engine.fill.JRFillChart.<init>(JRFillChart.java:253) at net.sf.jasperreports.engine.fill.JRFillObjectFactory.getChart(JRFillObjectFactory.java:464) at net.sf.jasperreports.engine.base.JRBaseChart.getCopy(JRBaseChart.java:430) at net.sf.jasperreports.engine.fill.JRFillElementGroup.<init>(JRFillElementGroup.java:87) at net.sf.jasperreports.engine.fill.JRFillBand.<init>(JRFillBand.java:113) at net.sf.jasperreports.engine.fill.JRFillObjectFactory.getBand(JRFillObjectFactory.java:287) at net.sf.jasperreports.engine.fill.JRBaseFiller.<init>(JRBaseFiller.java:579) at net.sf.jasperreports.engine.fill.JRVerticalFiller.<init>(JRVerticalFiller.java:93) at net.sf.jasperreports.engine.fill.JRVerticalFiller.<init>(JRVerticalFiller.java:75) at net.sf.jasperreports.engine.fill.JRFiller.createFiller(JRFiller.java:113) at net.sf.jasperreports.engine.fill.JRFiller.fillReport(JRFiller.java:83) at net.sf.jasperreports.engine.JasperFillManager.fillReport(JasperFillManager.java:428) at net.sf.jasperreports.engine.JasperFillManager.fillReport(JasperFillManager.java:344) at it.businesslogic.ireport.IReportCompiler.run(IReportCompiler.java:604) at java.lang.Thread.run(Unknown Source) Print not filled. Try to use an EmptyDataSource...! By the web application, the error is the same. Please everyone, what should I do???