Hibernate Error : org.hibernate.MappingException: Unknown entity

[Sanghamitra Parida]

Hello Experts,

I am new to hibernate. I am getting the below error:

org.hibernate.MappingException: Unknown entity: secDemo.Publisher
at org.hibernate.impl.SessionFactoryImpl.getEntityPersister(SessionFactoryImpl.java:489)
at org.hibernate.impl.SessionImpl.getEntityPersister(SessionImpl.java:1021)
at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:83)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:184)
at org.hibernate.event.def.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:33)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:173)
at org.hibernate.event.def.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:27)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:69)
at org.hibernate.impl.SessionImpl.save(SessionImpl.java:429)
at org.hibernate.impl.SessionImpl.save(SessionImpl.java:424)
at secDemo.FirstHibernateProgram.main(FirstHibernateProgram.java:29)

My code goes here:

import java.io.Serializable;
import javax.persistence.Column;
import javax.persistence.Id;
import javax.persistence.Entity;
import javax.persistence.Table;
@Entity
@Table(name = "PUBLISHER", schema = "public")
public class Publisher implements Serializable{
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	@Id
	private Long id;
	@Column(name = "CODE")
	private String code;
	@Column(name = "PUBLISHER_NAME")
	private String name;
	@Column(name = "ADDRESS")
	private String address;

	public Long getId() {
		return id;
	}

	public void setId(Long id) {
		this.id = id;
	}

	public String getCode() {
		return code;
	}

	public void setCode(String code) {
		this.code = code;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public String getAddress() {
		return address;
	}

	public void setAddress(String address) {
		this.address = address;
	}
}

The main class code:

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

/**
 * @author www.javaworkspace.com
 * 
 */
public class FirstHibernateProgram {

	/**
	 * @param args
	 */
	public static void main(String[] args) {

		Configuration configuration = new Configuration().configure();
		SessionFactory factory = configuration.buildSessionFactory();

		Session session = factory.openSession();

		try {
			Publisher publisher = new Publisher();
			publisher.setId(15l); // for long value suffix l at last
			publisher.setCode("SUN");
			publisher.setName("First Hibernate Example. www.javaworkspace.com");
			publisher.setAddress("Workspace");
			session.save(publisher);
			session.flush();
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			session.close();
		}
	}
}

Could you please kind enough to tell me where I am going wrong?

Regards
Sasanka

[Bill Gorder]

You need to specify your entities somewhere you can either add a <mapping class= to your hibernate.cfg.xml or add them using AnnotationConfiguration()

Read section 1.2
http://docs.jboss.org/hibernate/annotations/3.5/reference/en/html/ch01.html#setup-configuration

[Kaustubh G Sharma]

I am having same issue.. and tried all solution mentioned over here.... but it still not working

Kaustubh G Sharma wrote:
Hello I tried to run a hibernate 2 example but getting org.hibernate.MappingException: Unknown entity: com.training.HelloWorld ... Please help. Can see my code below

package com.training;

import java.io.Serializable;

public class HelloWorld implements Serializable{

	private long id;
	private String text;
	public long getId() {
		return id;
	}
	public void setId(long id) {
		this.id = id;
	}
	public String getText() {
		return text;
	}
	public void setText(String text) {
		this.text = text;
	}
	
	
	
}

package com.training;

import java.util.Iterator;
import java.util.Set;

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

public class TestHelloWorld {
	
	public static void main(String[] args) {
		Session session = null;

		try{
			// This step will read hibernate.cfg.xml and prepare hibernate for use
			//SessionFactory sessionFactory = new AnnotationConfiguration().configure("hibernate_helloWorld_Annotation.cfg.xml").buildSessionFactory();
			SessionFactory sessionFactory = new Configuration().configure("hibernate.cfg.xml").buildSessionFactory();
			 session =sessionFactory.openSession();             
			 Transaction tx = session.beginTransaction();
				//Create new instance of Contact and set values in it by reading them from form object
			 	HelloWorld helloWorld = new HelloWorld();
			 	helloWorld.setId(1);
			 	helloWorld.setText("Hello World!");
				session.save(helloWorld);
				helloWorld = (HelloWorld)session.get(HelloWorld.class, new Long(1));
				//tx.commit();
				
				System.out.println("DAta is :"+helloWorld.getText());

		}catch(Exception e){
			e.printStackTrace();
			System.out.println(e.getMessage());
		}finally{
			// Actual contact insertion will happen at this step
			System.out.println("test");
			 session.flush();
			 session.close();
			}
		
	}


}

<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<hibernate-configuration>
<session-factory>

		<property name="hibernate.connection.driver_class">oracle.jdbc.driver.OracleDriver</property>
     <!--  <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
      <property name="hibernate.connection.url">jdbc:mysql://localhost/hibernatetutorial</property>
      <property name="dialect">org.hibernate.dialect.MySQLDialect</property>
       -->
       <property name="hibernate.connection.url">jdbc:oracle:thin:@localhost:1521:xe</property>	
      <property name="hibernate.connection.username">SYSTEM</property>
      <property name="hibernate.connection.password">root</property>
      <property name="hibernate.connection.pool_size">10</property>
      <property name="show_sql">true</property>
      <property name="connection.autocommit">true</property>
      <property name="dialect">org.hibernate.dialect.OracleDialect</property>
      
      
     <property name="hibernate.hbm2ddl.auto">create</property>
    
       <mapping class="com.training.HelloWorld"/>
       
  
     
</session-factory>
</hibernate-configuration>

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC 
    "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
    "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
  <class name="com.nihilent.training.HelloWorld" table="HELLOWORLD">
	   <id name="id" type="long" column="ID" >
	   <generator class="assigned"/>
	  </id>
	  <property name="text">
		 <column name="TEXT" />
	  </property>
   </class>
   
    
</hibernate-mapping>