Hibernate错误 ，Unknown entity: com.gssh.entity.Employee

Employee.java

package com.gssh.entity;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;
@Entity
@Table(name="employee")
public class Employee {
  private int id;
  private String firstName; 
  private String lastName;   
  private int salary;
  public Employee() {}
  public Employee(String fname, String lname, int salary) {
     this.firstName = fname;
     this.lastName = lname;
     this.salary = salary;
  }
@Id
   @GeneratedValue
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
public int getSalary() {
return salary;
}
public void setSalary(int salary) {
this.salary = salary;
} 
  

}

Employee.hbm.xml

  "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
  "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">

 
   
     
   
     
   
   
    
   

 

  hibernate.cfg.xml

     "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
     "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">

 
   
    org.hibernate.dialect.MySQLDialect
   
    jdbc:mysql://localhost:3306/factory?
   
    root
   
    root
   
    com.mysql.jdbc.Driver
   
    true
   
    update
   
   
     
 

ManageEmployee.java

package com.gssh.entity;
import java.util.List; 
import java.util.Date;
import java.util.Iterator; 


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


public class ManageEmployee {
   private static SessionFactory factory; 
   public static void main(String[] args) {
      try{
         factory = new Configuration().configure().buildSessionFactory();
      }catch (Throwable ex) { 
         System.err.println("Failed to create sessionFactory object." + ex);
         throw new ExceptionInInitializerError(ex); 
      }
      ManageEmployee ME = new ManageEmployee();


      /* Add few employee records in database */
      Integer empID1 = ME.addEmployee("Zara", "Ali", 1000);
      Integer empID2 = ME.addEmployee("Daisy", "Das", 5000);
      Integer empID3 = ME.addEmployee("John", "Paul", 10000);


      /* List down all the employees */
      ME.listEmployees();


      /* Update employee's records */
      ME.updateEmployee(empID1, 5000);


      /* Delete an employee from the database */
      ME.deleteEmployee(empID2);


      /* List down new list of the employees */
      ME.listEmployees();
   }
   /* Method to CREATE an employee in the database */
   public Integer addEmployee(String fname, String lname, int salary){
      Session session = factory.openSession();
      Transaction tx = null;
      Integer employeeID = null;
      try{
         tx = session.beginTransaction();
         Employee employee = new Employee(fname, lname, salary);
         employeeID = (Integer) session.save(employee); 
         tx.commit();
      }catch (HibernateException e) {
         if (tx!=null) tx.rollback();
         e.printStackTrace(); 
      }finally {
         session.close(); 
      }
      return employeeID;
   }
   /* Method to  READ all the employees */
   public void listEmployees( ){
      Session session = factory.openSession();
      Transaction tx = null;
      try{
         tx = session.beginTransaction();
         List employees = session.createQuery("from Employee").list(); 
         for (Iterator iterator = 
                           employees.iterator(); iterator.hasNext();){
            Employee employee = (Employee) iterator.next(); 
            System.out.print("First Name: " + employee.getFirstName()); 
            System.out.print("  Last Name: " + employee.getLastName()); 
            System.out.println("  Salary: " + employee.getSalary()); 
         }
         tx.commit();
      }catch (HibernateException e) {
         if (tx!=null) tx.rollback();
         e.printStackTrace(); 
      }finally {
         session.close(); 
      }
   }
   /* Method to UPDATE salary for an employee */
   public void updateEmployee(Integer EmployeeID, int salary ){
      Session session = factory.openSession();
      Transaction tx = null;
      try{
         tx = session.beginTransaction();
         Employee employee = 
                    (Employee)session.get(Employee.class, EmployeeID); 
         employee.setSalary( salary );
         session.update(employee); 
         tx.commit();
      }catch (HibernateException e) {
         if (tx!=null) tx.rollback();
         e.printStackTrace(); 
      }finally {
         session.close(); 
      }
   }
   /* Method to DELETE an employee from the records */
   public void deleteEmployee(Integer EmployeeID){
      Session session = factory.openSession();
      Transaction tx = null;
      try{
         tx = session.beginTransaction();
         Employee employee = 
                   (Employee)session.get(Employee.class, EmployeeID); 
         session.delete(employee); 
         tx.commit();
      }catch (HibernateException e) {
         if (tx!=null) tx.rollback();
         e.printStackTrace(); 
      }finally {
         session.close(); 
      }
   }

}

运行时报错

org.hibernate.MappingException: Unknown entity: com.gssh.entity.Employee
at org.hibernate.internal.SessionFactoryImpl.getEntityPersister(SessionFactoryImpl.java:1141)
at org.hibernate.internal.SessionImpl.getEntityPersister(SessionImpl.java:1433)
at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:116)
at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:206)
at org.hibernate.event.internal.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:55)
at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:191)
at org.hibernate.event.internal.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:49)
at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:90)
at org.hibernate.internal.SessionImpl.fireSave(SessionImpl.java:764)
at org.hibernate.internal.SessionImpl.save(SessionImpl.java:756)
at org.hibernate.internal.SessionImpl.save(SessionImpl.java:752)
at com.gssh.entity.ManageEmployee.addEmployee(ManageEmployee.java:48)
at com.gssh.entity.ManageEmployee.main(ManageEmployee.java:24)
org.hibernate.MappingException: Unknown entity: com.gssh.entity.Employee
at org.hibernate.internal.SessionFactoryImpl.getEntityPersister(SessionFactoryImpl.java:1141)
at org.hibernate.internal.SessionImpl.getEntityPersister(SessionImpl.java:1433)
at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:116)
at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:206)
at org.hibernate.event.internal.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:55)
at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:191)
at org.hibernate.event.internal.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:49)
at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:90)
at org.hibernate.internal.SessionImpl.fireSave(SessionImpl.java:764)
at org.hibernate.internal.SessionImpl.save(SessionImpl.java:756)
at org.hibernate.internal.SessionImpl.save(SessionImpl.java:752)
at com.gssh.entity.ManageEmployee.addEmployee(ManageEmployee.java:48)
at com.gssh.entity.ManageEmployee.main(ManageEmployee.java:25)
org.hibernate.MappingException: Unknown entity: com.gssh.entity.Employee
at org.hibernate.internal.SessionFactoryImpl.getEntityPersister(SessionFactoryImpl.java:1141)
at org.hibernate.internal.SessionImpl.getEntityPersister(SessionImpl.java:1433)
at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:116)
at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:206)
at org.hibernate.event.internal.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:55)
at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:191)
at org.hibernate.event.internal.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:49)
at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:90)
at org.hibernate.internal.SessionImpl.fireSave(SessionImpl.java:764)
at org.hibernate.internal.SessionImpl.save(SessionImpl.java:756)
at org.hibernate.internal.SessionImpl.save(SessionImpl.java:752)
at com.gssh.entity.ManageEmployee.addEmployee(ManageEmployee.java:48)
at com.gssh.entity.ManageEmployee.main(ManageEmployee.java:26)
org.hibernate.hql.internal.ast.QuerySyntaxException: Employee is not mapped [from Employee]
at org.hibernate.hql.internal.ast.util.SessionFactoryHelper.requireClassPersister(SessionFactoryHelper.java:180)
at org.hibernate.hql.internal.ast.tree.FromElementFactory.addFromElement(FromElementFactory.java:110)
at org.hibernate.hql.internal.ast.tree.FromClause.addFromElement(FromClause.java:93)
at org.hibernate.hql.internal.ast.HqlSqlWalker.createFromElement(HqlSqlWalker.java:324)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromElement(HqlSqlBaseWalker.java:3420)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromElementList(HqlSqlBaseWalker.java:3309)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromClause(HqlSqlBaseWalker.java:706)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.query(HqlSqlBaseWalker.java:562)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.selectStatement(HqlSqlBaseWalker.java:299)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.statement(HqlSqlBaseWalker.java:247)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.analyze(QueryTranslatorImpl.java:249)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:184)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:137)
at org.hibernate.engine.query.spi.HQLQueryPlan.(HQLQueryPlan.java:105)
at org.hibernate.engine.query.spi.HQLQueryPlan.(HQLQueryPlan.java:80)
at org.hibernate.engine.query.spi.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:168)
at org.hibernate.internal.AbstractSessionImpl.getHQLQueryPlan(AbstractSessionImpl.java:221)
at org.hibernate.internal.AbstractSessionImpl.createQuery(AbstractSessionImpl.java:199)
at org.hibernate.internal.SessionImpl.createQuery(SessionImpl.java:1778)
at com.gssh.entity.ManageEmployee.listEmployees(ManageEmployee.java:64)
at com.gssh.entity.ManageEmployee.main(ManageEmployee.java:29)
org.hibernate.MappingException: Unknown entity: com.gssh.entity.Employee
at org.hibernate.internal.SessionFactoryImpl.getEntityPersister(SessionFactoryImpl.java:1141)
at org.hibernate.internal.SessionImpl.locateEntityPersister(SessionImpl.java:2487)
at org.hibernate.internal.SessionImpl.access$1900(SessionImpl.java:175)
at org.hibernate.internal.SessionImpl$IdentifierLoadAccessImpl.(SessionImpl.java:2429)
at org.hibernate.internal.SessionImpl$IdentifierLoadAccessImpl.(SessionImpl.java:2433)
at org.hibernate.internal.SessionImpl$IdentifierLoadAccessImpl.(SessionImpl.java:2420)
at org.hibernate.internal.SessionImpl.byId(SessionImpl.java:1065)
at org.hibernate.internal.SessionImpl.get(SessionImpl.java:988)
at com.gssh.entity.ManageEmployee.updateEmployee(ManageEmployee.java:87)
at com.gssh.entity.ManageEmployee.main(ManageEmployee.java:32)
org.hibernate.MappingException: Unknown entity: com.gssh.entity.Employee
at org.hibernate.internal.SessionFactoryImpl.getEntityPersister(SessionFactoryImpl.java:1141)
at org.hibernate.internal.SessionImpl.locateEntityPersister(SessionImpl.java:2487)
at org.hibernate.internal.SessionImpl.access$1900(SessionImpl.java:175)
at org.hibernate.internal.SessionImpl$IdentifierLoadAccessImpl.(SessionImpl.java:2429)
at org.hibernate.internal.SessionImpl$IdentifierLoadAccessImpl.(SessionImpl.java:2433)
at org.hibernate.internal.SessionImpl$IdentifierLoadAccessImpl.(SessionImpl.java:2420)
at org.hibernate.internal.SessionImpl.byId(SessionImpl.java:1065)
at org.hibernate.internal.SessionImpl.get(SessionImpl.java:988)
at com.gssh.entity.ManageEmployee.deleteEmployee(ManageEmployee.java:105)
at com.gssh.entity.ManageEmployee.main(ManageEmployee.java:35)
org.hibernate.hql.internal.ast.QuerySyntaxException: Employee is not mapped [from Employee]
at org.hibernate.hql.internal.ast.util.SessionFactoryHelper.requireClassPersister(SessionFactoryHelper.java:180)
at org.hibernate.hql.internal.ast.tree.FromElementFactory.addFromElement(FromElementFactory.java:110)
at org.hibernate.hql.internal.ast.tree.FromClause.addFromElement(FromClause.java:93)
at org.hibernate.hql.internal.ast.HqlSqlWalker.createFromElement(HqlSqlWalker.java:324)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromElement(HqlSqlBaseWalker.java:3420)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromElementList(HqlSqlBaseWalker.java:3309)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromClause(HqlSqlBaseWalker.java:706)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.query(HqlSqlBaseWalker.java:562)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.selectStatement(HqlSqlBaseWalker.java:299)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.statement(HqlSqlBaseWalker.java:247)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.analyze(QueryTranslatorImpl.java:249)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:184)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:137)
at org.hibernate.engine.query.spi.HQLQueryPlan.(HQLQueryPlan.java:105)
at org.hibernate.engine.query.spi.HQLQueryPlan.(HQLQueryPlan.java:80)
at org.hibernate.engine.query.spi.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:168)
at org.hibernate.internal.AbstractSessionImpl.getHQLQueryPlan(AbstractSessionImpl.java:221)
at org.hibernate.internal.AbstractSessionImpl.createQuery(AbstractSessionImpl.java:199)
at org.hibernate.internal.SessionImpl.createQuery(SessionImpl.java:1778)
at com.gssh.entity.ManageEmployee.listEmployees(ManageEmployee.java:64)

at com.gssh.entity.ManageEmployee.main(ManageEmployee.java:38)

请问这边是什么问题呢