Erro na geração de relatorio com jasperriport como resolver?

olá galera do guj,
estou com um problema com a geração de relatorio do meu sistema quando clico em gerar relatorio aparece um mensagem de erro e não sei por que isso está ocorrendo pq antes ele funcionava normalmente.
abaixo tenho o código que faz a chamada do relatorio:

try{ Connection con = new Conexao().getConnection(); HashMap parameters = new HashMap(); parameters.put("num_amostra", numAmostraField.getText()); JasperPrint jp = JasperFillManager.fillReport("c:/Arquivos de programas/programa/relatorio/Relatorio_Bacteriologica.jasper", parameters, con); JasperViewer jrv = new JasperViewer(jp,false); jrv.setVisible(true); } catch(Exception e){ e.printStackTrace(); }

esse é o erro que está aparecendo:
Exception in thread “AWT-EventQueue-0” java.lang.NoClassDefFoundError: Lorg/apache/commons/logging/Log;
at java.lang.Class.getDeclaredFields0(Native Method)
at java.lang.Class.privateGetDeclaredFields(Class.java:2291)
at java.lang.Class.getDeclaredField(Class.java:1880)
at java.io.ObjectStreamClass.getDeclaredSUID(ObjectStreamClass.java:1610)
at java.io.ObjectStreamClass.access$700(ObjectStreamClass.java:52)
at java.io.ObjectStreamClass$2.run(ObjectStreamClass.java:425)
at java.security.AccessController.doPrivileged(Native Method)
at java.io.ObjectStreamClass.(ObjectStreamClass.java:413)
at java.io.ObjectStreamClass.lookup(ObjectStreamClass.java:310)
at java.io.ObjectStreamClass.initNonProxy(ObjectStreamClass.java:547)
at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1583)
at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1496)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1732)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1329)
at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1947)
at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1871)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1753)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1329)
at java.io.ObjectInputStream.readArray(ObjectInputStream.java:1667)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1323)
at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1947)
at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1871)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1753)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1329)
at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1947)
at java.io.ObjectInputStream.defaultReadObject(ObjectInputStream.java:480)
at net.sf.jasperreports.engine.base.JRBaseReport.readObject(JRBaseReport.java:742)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:974)
at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1849)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1753)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1329)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:351)
at net.sf.jasperreports.engine.util.JRLoader.loadObject(JRLoader.java:90)
at net.sf.jasperreports.engine.JasperFillManager.fillReport(JasperFillManager.java:243)
at br.com.programa.BacteriologicaView.jButton1ActionPerformed(BacteriologicaView.java:820)
at br.com.programa.BacteriologicaView.access$900(BacteriologicaView.java:37)
at br.com.programa.BacteriologicaView$FormListener.actionPerformed(BacteriologicaView.java:741)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2318)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:236)
at java.awt.Component.processMouseEvent(Component.java:6263)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3267)
at java.awt.Component.processEvent(Component.java:6028)
at java.awt.Container.processEvent(Container.java:2041)
at java.awt.Component.dispatchEventImpl(Component.java:4630)
at java.awt.Container.dispatchEventImpl(Container.java:2099)
at java.awt.Component.dispatchEvent(Component.java:4460)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4574)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4238)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4168)
at java.awt.Container.dispatchEventImpl(Container.java:2085)
at java.awt.Window.dispatchEventImpl(Window.java:2478)
at java.awt.Component.dispatchEvent(Component.java:4460)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)
Caused by: java.lang.ClassNotFoundException: org.apache.commons.logging.Log
at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
… 66 more

espero que vcs possam me ajudar a resolver esse problema. agradeço desde já

Boa noite amigo

Está faltando a biblioteca Apache Commons no seu projeto.

Aqui voçê a encontra: http://commons.apache.org/

Espero ter ajudado,

Abços.