sto cercando di generare un report pdf con JasperReports e mi viene segnalato un errore (credo) nel metodo fillReport...di seguito posto il codice e l'eccezione sollevata:

codice:
package principale;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

import net.sf.jasperreports.engine.JRException;
import net.sf.jasperreports.engine.JasperCompileManager;
import net.sf.jasperreports.engine.JasperExportManager;
import net.sf.jasperreports.engine.JasperFillManager;
import net.sf.jasperreports.engine.JasperPrint;
import net.sf.jasperreports.engine.design.JasperDesign;
import net.sf.jasperreports.engine.xml.JRXmlLoader;

public class Avvio
{
  public static String JASPER_REPORT_FOLDER = "C:\\TEMP\\";
  public static String JASPER_FILENAME      = "SituazionePrenotazioni";
  public static String DRIVER               = "com.mysql.jdbc.Driver";
  public static String DB_URL               = "jdbc:mysql://localhost/schedule";
  public static String DB_NAME              = "schedule";
  public static String DB_USERNAME          = "root";
  public static String DB_PASSWORD          = "";
  
  public static void main(String[] args) throws ClassNotFoundException, SQLException, JRException {

    //inizializzazione connessione al database
    Class.forName(DRIVER);
    Connection conn = DriverManager.getConnection(DB_URL, DB_USERNAME, DB_PASSWORD);
    
    //rendering e generazione del file PDF
    JasperPrint sitPren = JasperFillManager.fillReport(JASPER_REPORT_FOLDER + JASPER_FILENAME +	".jasper", null, conn);
    JasperExportManager.exportReportToPdfFile(sitPren, JASPER_REPORT_FOLDER + "report.pdf");

  }
}
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/commons/logging/LogFactory
at net.sf.jasperreports.engine.fill.JRBaseFiller.<cli nit>(JRBaseFiller.java:96)
at net.sf.jasperreports.engine.fill.JRFiller.createFi ller(JRFiller.java:147)
at net.sf.jasperreports.engine.fill.JRFiller.fillRepo rt(JRFiller.java:57)
at net.sf.jasperreports.engine.JasperFillManager.fill Report(JasperFillManager.java:402)
at net.sf.jasperreports.engine.JasperFillManager.fill Report(JasperFillManager.java:234)
at principale.Avvio.main(Avvio.java:32)
Caused by: java.lang.ClassNotFoundException: org.apache.commons.logging.LogFactory
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClassInternal(Unknown Source)
... 6 more