when I add the code into my spring configuration file beans-hibernate.xml <bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager"> <property name="sessionFactory" ref="sessionFactory" /> </bean> It doesn't work and I don't know why, can someone help me please ? My Dao Class is : public class CourseDaoImpl implements CourseDao { private SessionFactory sessionFactory; public void setSessionFactory(SessionFactory sessionFactory) { this.sessionFactory = sessionFactory; } @Transactional public void store(Course course) { sessionFactory.getCurrentSession().saveOrUpdate(course); } @Transactional public void delete(Long courseId) { Course course = (Course)sessionFactory.getCurrentSession().get(Course.class, courseId); sessionFactory.getCurrentSession().delete(course); } @Transactional(readOnly=true) public Course findById(Long courseId) { return (Course)sessionFactory.getCurrentSession().get(Course.class, courseId); } @Transactional public List<Course> findAll() { Query query = sessionFactory.getCurrentSession().createQuery("FROM Course"); return (List<Course>)query.list(); } } but : juil. 04, 2012 3:38:18 AM org.springframework.context.support.AbstractApplicationContext prepareRefresh Infos: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@6ba8fb1b: startup date [Wed Jul 04 03:38:18 CEST 2012]; root of context hierarchy juil. 04, 2012 3:38:18 AM org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions Infos: Loading XML bean definitions from class path resource [beans-hibernate.xml] juil. 04, 2012 3:38:19 AM org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons Infos: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@5a7fed46: defining beans [org.springframework.aop.config.internalAutoProxyCreator,org.springframework.transaction.annotation.AnnotationTransactionAttributeSource#0,org.springframework.transaction.interceptor.TransactionInterceptor#0,org.springframework.transaction.config.internalTransactionAdvisor,sessionFactory,transactionManager,courseDao]; root of factory hierarchy juil. 04, 2012 3:38:19 AM org.hibernate.annotations.common.Version INFO: HCANN000001: Hibernate Commons Annotations {4.0.1.Final} juil. 04, 2012 3:38:19 AM org.hibernate.Version logVersion INFO: HHH000412: Hibernate Core {4.1.3.Final} juil. 04, 2012 3:38:19 AM org.hibernate.cfg.Environment INFO: HHH000206: hibernate.properties not found juil. 04, 2012 3:38:19 AM org.hibernate.cfg.Environment buildBytecodeProvider INFO: HHH000021: Bytecode provider name : javassist juil. 04, 2012 3:38:19 AM org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure INFO: HHH000402: Using Hibernate built-in connection pool (not for production use!) juil. 04, 2012 3:38:19 AM org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure INFO: HHH000115: Hibernate connection pool size: 20 juil. 04, 2012 3:38:19 AM org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure INFO: HHH000006: Autocommit mode: false juil. 04, 2012 3:38:19 AM org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure INFO: HHH000401: using driver [org.hibernate.dialect.PostgreSQLDialect] at URL [jdbc:postgresql://localhost:5432/spring] juil. 04, 2012 3:38:19 AM org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure INFO: HHH000046: Connection properties: {user=Bilal, password=**} juil. 04, 2012 3:38:19 AM org.hibernate.dialect.Dialect INFO: HHH000400: Using dialect: org.hibernate.dialect.PostgreSQLDialect juil. 04, 2012 3:38:19 AM org.hibernate.engine.jdbc.internal.LobCreatorBuilder useContextualLobCreation INFO: HHH000423: Disabling contextual LOB creation as JDBC driver reported JDBC version [3] less than 4 juil. 04, 2012 3:38:19 AM org.hibernate.engine.transaction.internal.TransactionFactoryInitiator initiateService INFO: HHH000399: Using default transaction strategy (direct JDBC transactions) juil. 04, 2012 3:38:19 AM org.hibernate.hql.internal.ast.ASTQueryTranslatorFactory INFO: HHH000397: Using ASTQueryTranslatorFactory juil. 04, 2012 3:38:19 AM org.hibernate.tool.hbm2ddl.SchemaUpdate execute INFO: HHH000228: Running hbm2ddl schema update juil. 04, 2012 3:38:19 AM org.hibernate.tool.hbm2ddl.SchemaUpdate execute INFO: HHH000102: Fetching database metadata juil. 04, 2012 3:38:19 AM org.hibernate.tool.hbm2ddl.SchemaUpdate execute INFO: HHH000396: Updating schema juil. 04, 2012 3:38:19 AM org.hibernate.tool.hbm2ddl.TableMetadata INFO: HHH000261: Table found: public.course juil. 04, 2012 3:38:19 AM org.hibernate.tool.hbm2ddl.TableMetadata INFO: HHH000037: Columns: [fee, id, title, end_date, begin_date] juil. 04, 2012 3:38:19 AM org.hibernate.tool.hbm2ddl.TableMetadata INFO: HHH000108: Foreign keys: [] juil. 04, 2012 3:38:19 AM org.hibernate.tool.hbm2ddl.TableMetadata INFO: HHH000126: Indexes: [course_pkey] juil. 04, 2012 3:38:19 AM org.hibernate.tool.hbm2ddl.SchemaUpdate execute INFO: HHH000232: Schema update complete juil. 04, 2012 3:38:19 AM org.springframework.beans.factory.support.DefaultSingletonBeanRegistry destroySingletons Infos: Destroying singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@5a7fed46: defining beans [org.springframework.aop.config.internalAutoProxyCreator,org.springframework.transaction.annotation.AnnotationTransactionAttributeSource#0,org.springframework.transaction.interceptor.TransactionInterceptor#0,org.springframework.transaction.config.internalTransactionAdvisor,sessionFactory,transactionManager,courseDao]; root of factory hierarchy juil. 04, 2012 3:38:19 AM org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl stop INFO: HHH000030: Cleaning up connection pool [jdbc:postgresql://localhost:5432/spring] Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'transactionManager' defined in class path resource [beans-hibernate.xml]: Invocation of init method failed; nested exception is java.lang.NoClassDefFoundError: org/hibernate/engine/SessionFactoryImplementor at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1455) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456) at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:294) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:225) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:291) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193) at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:585) at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:913) at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:464) at org.springframework.context.support.ClassPathXmlApplicationContext.(ClassPathXmlApplicationContext.java:139) at org.springframework.context.support.ClassPathXmlApplicationContext.(ClassPathXmlApplicationContext.java:83) at com.boutaya.bill.main.Main.main(Main.java:14) Caused by: java.lang.NoClassDefFoundError: org/hibernate/engine/SessionFactoryImplementor at org.springframework.orm.hibernate3.SessionFactoryUtils.getDataSource(SessionFactoryUtils.java:123) at org.springframework.orm.hibernate3.HibernateTransactionManager.afterPropertiesSet(HibernateTransactionManager.java:411) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1514) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1452) ... 12 more Caused by: java.lang.ClassNotFoundException: org.hibernate.engine.SessionFactoryImplementor at java.net.URLClassLoader$1.run(Unknown Source) 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) ... 16 more I think the problem is when I use the Class : org.springframework.orm.hibernate3.HibernateTransactionManager ???