Ciao, mi sono imbattuto in questo "pacco" natalizio:
Nella generazione di un report con le librerie jasper mi dà questo errore:


log4j:WARN No appenders could be found for logger (net.sf.jasperreports.extensions.ExtensionsEnviron ment).
log4j:WARN Please initialize the log4j system properly.
Exception in thread "AWT-EventQueue-0" java.lang.NoClassDefFoundError: net/sf/jasperreports/compilers/GroovyEvaluator
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java :800)
at net.sf.jasperreports.engine.util.JRClassLoader.loa dClass(JRClassLoader.java:338)
at net.sf.jasperreports.engine.util.JRClassLoader.loa dClassFromBytes(JRClassLoader.java:261)
at net.sf.jasperreports.engine.design.JRAbstractJavaC ompiler.loadEvaluator(JRAbstractJavaCompiler.java: 102)
at net.sf.jasperreports.engine.design.JRAbstractCompi ler.loadEvaluator(JRAbstractCompiler.java:333)
at net.sf.jasperreports.engine.JasperCompileManager.g etEvaluator(JasperCompileManager.java:265)
at net.sf.jasperreports.engine.fill.JRFillDataset.cre ateCalculator(JRFillDataset.java:457)
at net.sf.jasperreports.engine.fill.JRBaseFiller.<ini t>(JRBaseFiller.java:379)
at net.sf.jasperreports.engine.fill.JRVerticalFiller. <init>(JRVerticalFiller.java:88)
at net.sf.jasperreports.engine.fill.JRVerticalFiller. <init>(JRVerticalFiller.java:103)
at net.sf.jasperreports.engine.fill.JRVerticalFiller. <init>(JRVerticalFiller.java:61)
at net.sf.jasperreports.engine.fill.JRFiller.createFi ller(JRFiller.java:153)
at net.sf.jasperreports.engine.fill.JRFiller.fill(JRF iller.java:55)
at net.sf.jasperreports.engine.JasperFillManager.fill (JasperFillManager.java:446)
at net.sf.jasperreports.engine.JasperFillManager.fill (JasperFillManager.java:276)
at net.sf.jasperreports.engine.JasperFillManager.fill Report(JasperFillManager.java:745)
at lotus.Consegna.print(Consegna.java:696)
at lotus.Lotus.jBPrintActionPerformed(Lotus.java:496)
at lotus.Lotus.access$400(Lotus.java:33)
at lotus.Lotus$5.actionPerformed(Lotus.java:142)
at javax.swing.AbstractButton.fireActionPerformed(Abs tractButton.java:2018)
at javax.swing.AbstractButton$Handler.actionPerformed (AbstractButton.java:2341)
at javax.swing.DefaultButtonModel.fireActionPerformed (DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultB uttonModel.java:259)
at javax.swing.plaf.basic.BasicButtonListener.mouseRe leased(BasicButtonListener.java:252)
at java.awt.Component.processMouseEvent(Component.jav a:6505)
at javax.swing.JComponent.processMouseEvent(JComponen t.java:3320)
at java.awt.Component.processEvent(Component.java:627 0)
at java.awt.Container.processEvent(Container.java:222 9)
at java.awt.Component.dispatchEventImpl(Component.jav a:4861)
at java.awt.Container.dispatchEventImpl(Container.jav a:2287)
at java.awt.Component.dispatchEvent(Component.java:46 87)
at java.awt.LightweightDispatcher.retargetMouseEvent( Container.java:4832)
at java.awt.LightweightDispatcher.processMouseEvent(C ontainer.java:4492)
at java.awt.LightweightDispatcher.dispatchEvent(Conta iner.java:4422)
at java.awt.Container.dispatchEventImpl(Container.jav a:2273)
at java.awt.Window.dispatchEventImpl(Window.java:2719 )
at java.awt.Component.dispatchEvent(Component.java:46 87)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.j ava:735)
at java.awt.EventQueue.access$200(EventQueue.java:103 )
at java.awt.EventQueue$3.run(EventQueue.java:694)
at java.awt.EventQueue$3.run(EventQueue.java:692)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPri vilege(ProtectionDomain.java:76)
at java.security.ProtectionDomain$1.doIntersectionPri vilege(ProtectionDomain.java:87)
at java.awt.EventQueue$4.run(EventQueue.java:708)
at java.awt.EventQueue$4.run(EventQueue.java:706)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPri vilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java: 705)
at java.awt.EventDispatchThread.pumpOneEventForFilter s(EventDispatchThread.java:242)
at java.awt.EventDispatchThread.pumpEventsForFilter(E ventDispatchThread.java:161)
at java.awt.EventDispatchThread.pumpEventsForHierarch y(EventDispatchThread.java:150)
at java.awt.EventDispatchThread.pumpEvents(EventDispa tchThread.java:146)
at java.awt.EventDispatchThread.pumpEvents(EventDispa tchThread.java:138)
at java.awt.EventDispatchThread.run(EventDispatchThre ad.java:91)
Caused by: java.lang.ClassNotFoundException: net.sf.jasperreports.compilers.GroovyEvaluator
at java.lang.ClassLoader.findClass(ClassLoader.java:5 31)
at java.lang.ClassLoader.loadClass(ClassLoader.java:4 25)
at java.lang.ClassLoader.loadClass(ClassLoader.java:3 58)
... 57 more