Unknown entity: org.hibernate.impl.SessionImpl

Question

Hi I am getting below error during session.save(). I didn't know why it is coming. I am not using annotations. I am learning it from basics. Please look at below error. I have spend more than 2 hours on this, but couldn't find the solution:

Aug 17, 2016 8:32:47 PM org.hibernate.impl.SessionFactoryObjectFactory addInstance
INFO: Not binding factory to JNDI, no JNDI name configured
Exception in thread "main" org.hibernate.MappingException: Unknown entity: org.hibernate.impl.SessionImpl
    at org.hibernate.impl.SessionFactoryImpl.getEntityPersister(SessionFactoryImpl.java:548)
    at org.hibernate.impl.SessionImpl.getEntityPersister(SessionImpl.java:1338)
    at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:96)
    at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:186)
    at org.hibernate.event.def.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:33)
    at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:175)
    at org.hibernate.event.def.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:27)
    at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:70)
    at org.hibernate.impl.SessionImpl.fireSave(SessionImpl.java:535)
    at org.hibernate.impl.SessionImpl.save(SessionImpl.java:523)
    at org.hibernate.impl.SessionImpl.save(SessionImpl.java:519)
    at beans.Test.main(Test.java:24)


My Mapping file is : 

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC 
 "-//Hibernate/Hibernate Mapping DTD//EN"
 "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">

 <hibernate-mapping>
    <class name="beans.Student" table="Student" schema="mysql">
        <id name="id" column="id"/>
        <property name="name" column="name"/>
        <property name="email" column="email"/>
        <property name="marks" column="marks"/>
    </class>
 </hibernate-mapping>


My Hibernate-cfg-file :

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration SYSTEM 
"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">

<hibernate-configuration>
    <session-factory>
        <property name="hibernate.connection.driver_class">
            com.mysql.jdbc.Driver
        </property>

        <property name="hibernate.connection.url">
            jdbc:mysql://localhost:3306/mysql
        </property>

        <property name="hibernate.connection.username">
            root
        </property>

        <property name="hibernate.connection.password">
            ?123
        </property>

        <property name="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</property>

        <property name="hibernate.hbm2ddl_auto">create</property>
        <property name="hibernate.show_sql">true</property>

        <mapping resource="resources/Student.hbm.xml"/>
    </session-factory>
</hibernate-configuration>

I am getting this error at session.save(). Please Help out in this. I am new to this and learning hibernate from basics.

Answer 1

You should check which class you're trying to save using session object. I encountered the same problem, after going through code I found that I was trying to persist session object. So I simply removed this flaw and program ran smoothly