Hibernate erro

package modelo;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.AnnotationConfiguration;
import org.hibernate.cfg.Configuration;

public class TestaUsuario {

	public static void main(String[] args) {

		// configura o hibernate
		Configuration conf = new AnnotationConfiguration();
		conf.configure();
		SessionFactory factory = conf.buildSessionFactory();
		Session session = factory.openSession();
		// cria um usuario
		Usuario u = new Usuario();
	
		u.setLogin("admin");
		u.setSenha("admin");
		// abre transacao e insere
		Transaction t = session.beginTransaction();
		session.save(u);
		t.commit();
		session.close();
	}
}

Exception in thread “main” java.lang.NoClassDefFoundError: org/apache/commons/collections/map/LRUMap

at org.hibernate.util.SimpleMRUCache.init(SimpleMRUCache.java:71)

at org.hibernate.util.SimpleMRUCache.(SimpleMRUCache.java:55)

at org.hibernate.util.SimpleMRUCache.(SimpleMRUCache.java:50)

at org.hibernate.engine.query.QueryPlanCache.(QueryPlanCache.java:65)

at org.hibernate.impl.SessionFactoryImpl.(SessionFactoryImpl.java:176)

at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1327)18:37:15.921 [main] INFO  org.hibernate.cfg.SettingsFactory - Connection release mode: auto

at org.hibernate.cfg.AnnotationConfiguration.buildSessionFactory(AnnotationConfiguration.java:867)
at modelo.TestaUsuario.main(TestaUsuario.java:16)

Caused by: java.lang.ClassNotFoundException: org.apache.commons.collections.map.LRUMap

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)

… 8 more