"Unknown entity bean class"

Question

Hi there,
I'm learning using JPA by writing a web application example that check username and password. I use Sun Application Server 9.1 and Myeclipse to build and deloy.
I've got Runtime Exception:
Unknown entity bean class: class vn.kbnn.dtkb.system.dto.UserDTO, please verify that this class has been marked with the @Entity annotation.
Please help me because this error message is not help, my class have @Entity annotation already. Not redeploy bug also.
Here is my code:
package vn.kbnn.framework.controller;
// ... imports
public abstract class XApplicationManager implements ServletContextListener {
bq. protected static EntityManagerFactory entityManagerFactory; \\ protected static ThreadLocal<EntityManager> threadLocal; \\ protected static ServletContext servletContext; \\ protected static Logger logger;
//... contructors, setters, getters
package vn.kbnn.dtkb.controller;
//... imports
public class ApplicationManager extends XApplicationManager {
bq. public ApplicationManager() {bq. super(); \\ ApplicationManager.entityManagerFactory = Persistence.createEntityManagerFactory("vn.kbnn.dtkb.dao.JPA"); \\ ApplicationManager.threadLocal = new ThreadLocal<EntityManager>(); \\ ApplicationManager.logger = Logger.getLogger("vn.kbnn.dtkb.dao.Logger"); \\ logger.setLevel(Level.ALL);
bq. public void     contextInitialized(ServletContextEvent ce) {bq. ApplicationManager.servletContext = ce.getServletContext();
bq. public void contextDestroyed(ServletContextEvent ce) {}
package vn.kbnn.framework.dao;
//... imports
public abstract class XDAO {
bq. protected EntityManager em;
bq. public XDAO(EntityManagerFactory emf, ThreadLocal<EntityManager> threadLocal){bq. this.em = getEntityManager(_emf, _threadLocal);
     private EntityManager getEntityManager(EntityManagerFactory emf, ThreadLocal<EntityManager> threadLocal) {
bq. EntityManager manager = _threadLocal.get(); \\ if (manager == null || !manager.isOpen()) {bq. manager = _emf.createEntityManager(); \\ _threadLocal.set(manager);
          return manager;
package vn.kbnn.framework.system.dao;
//... imports
public abstract class XUserDAO extends XDAO {
bq. public XUserDAO(EntityManagerFactory emf, ThreadLocal<EntityManager> threadLocal) {bq. super(_emf, _threadLocal);
package vn.kbnn.dtkb.system.dao;
//... imports
public class UserDAO extends XUserDAO {
bq. public UserDAO(EntityManagerFactory emf, ThreadLocal<EntityManager> threadLocal) {bq. super(_emf, _threadLocal);
     public UserDTO findByPk(String _pk) throws RuntimeException {
bq. try {bq. UserDTO instance = em.find(UserDTO.class, _pk);
bq. return instance;
          } catch (RuntimeException re) {
bq. throw re;
package vn.kbnn.framework.facade;
public abstract class XFacade {
package vn.kbnn.framework.system.facade;
//... imports
bq. public abstract class XLoginFacade extends XFacade { \\ public abstract XUserDTO login(String _id, String _password) throws RuntimeException, XProfessionalException;
package vn.kbnn.dtkb.login.facade;
//... imports
public class LoginFacade extends XLoginFacade {
bq. public UserDTO login(String id, String password) throws RuntimeException, XProfessionalException{bq. UserDTO userDTO = new UserDTO(); \\ UserDAO userDAO = new UserDAO(ApplicationManager.getEntityManagerFactory(), ApplicationManager.getThreadLocal()); \\ try {bq. userDTO = userDAO.findByPk(_id);
bq. if (userDTO.getPassword() == _password) {
bq. bq. return userDTO;
bq. } else {
bq. bq. XProfessionalException xProfessionalException = new XProfessionalException("Id and password are not matched.");
bq. throw xProfessionalException;
bq. bq. }
bq. } catch (RuntimeException re){bq. throw re;
package vn.kbnn.framework.dto;
//... imports
@SuppressWarnings("serial")
@MappedSuperclass
public abstract class XDTO implements java.io.Serializable {
bq. @Id     @Column(name="pk", unique=true, nullable=false, insertable=true, updatable=false, length=8) \\ private String pk; \\ @Column(name="sid", unique=true, nullable=false, insertable=true, updatable=false, length=8) \\ private String sid;
//... constructors, setters, getters
package vn.kbnn.framework.system.dto;
//...imports
bq. @SuppressWarnings("serial") \\ @MappedSuperclass \\ public abstract class XUserDTO extends XDTO { \\ @Column(name="password", unique=false, nullable=false, insertable=true, updatable=true, length=8) \\ private String password;
//... contructors, setters, getters
package vn.kbnn.dtkb.system.dto;
*//... imports*
*@SuppressWarnings("serial")*
*@Entity*
*@Table(name = "t_User", schema = "DTKB")*
*public class UserDTO extends XUserDTO {*
bq. *public UserDTO() {*
bq. bq. super();
bq. *     }*
persistence.xml
<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd" version="1.0">
bq. <persistence-unit name="vn.kbnn.dtkb.dao.JPA" transaction-type="JTA">bq. <jta-data-source>jdbc/dtkb</jta-data-source>
     </persistence-unit>
</persistence>

Answer 1

I've got the same error for a long time and I still can't fix it, did you?