java.lang.ExceptionInInitializerError
Caused by: org.hibernate.MappingException: Could not determine type for: com.pra.dto.collections.Phone, at table: UserD_phone, for columns: [org.hibernate.mapping.Column(phone)]
   at org.hibernate.mapping.SimpleValue.getType(SimpleValue.java:306)
   at org.hibernate.mapping.SimpleValue.isValid(SimpleValue.java:290)
   at org.hibernate.mapping.Collection.validate(Collection.java:313)
   at org.hibernate.mapping.Set.validate(Set.java:42)
   at org.hibernate.cfg.Configuration.validate(Configuration.java:1336)
   at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1835)
   at base.SFCreator.<clinit>(SFCreator.java:9)
Exception in thread "main"

<?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">com.mysql.jdbc.Driver</property>
     <property name="hibernate.connection.url">jdbc:mysql://localhost/hibtut</property>
     <property name="hibernate.connection.username">root</property>
     <property name="hibernate.connection.password"></property>
     <property name="hibernate.connection.pool_size">10</property>
     <property name="show_sql">true</property>
     <property name="dialect">org.hibernate.dialect.MySQLDialect</property>
     <property name="hibernate.hbm2ddl.auto">create</property>
     <!-- Mapping files -->
     <mapping class="com.pra.dto.collections.Phone"/>
     <mapping class="com.pra.dto.collections.UserD"/>
</session-factory>
</hibernate-configuration>

package com.pra.dto.collections;

import java.util.HashSet;
import java.util.Set;

import javax.persistence.ElementCollection;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;

@Entity
public class UserD {

   private int userID;
   
   private String userName;
   
   private Set<Phone> phone = new HashSet<Phone>();

   @Id
   @GeneratedValue
   public int getUserID() {
      return userID;
   }

   public void setUserID(int userID) {
      this.userID = userID;
   }

   public String getUserName() {
      return userName;
   }

   public void setUserName(String userName) {
      this.userName = userName;
   }

   @ElementCollection
   public Set<Phone> getPhone() {
      return phone;
   }

   public void setPhone(Set<Phone> phone) {
      this.phone = phone;
   }

}

package com.pra.dto.collections;

import javax.persistence.GeneratedValue;
import javax.persistence.Id;


public class Phone {

   private int phoneID;
   
   private String phoneNo;

   @Id
   @GeneratedValue
   public int getPhoneID() {
      return phoneID;
   }

   public void setPhoneID(int phoneID) {
      this.phoneID = phoneID;
   }

   public String getPhoneNo() {
      return phoneNo;
   }

   public void setPhoneNo(String phoneNo) {
      this.phoneNo = phoneNo;
   }
   
}

package com.pra.dto.collections;

import org.hibernate.Session;

import base.SFCreator;

public class TestCollection extends SFCreator {
   public static void main(String[] args) {
      UserD detail = new UserD();
      detail.setUserName("Praveen");

      Phone p1 = new Phone();
      p1.setPhoneNo("34343434");

      Phone p2 = new Phone();
      p2.setPhoneNo("34343434");

      Phone p3 = new Phone();
      p3.setPhoneNo("34343434");

      Phone p4 = new Phone();
      p4.setPhoneNo("34343434");

      detail.getPhone().add(p1);
      detail.getPhone().add(p2);
      detail.getPhone().add(p3);
      detail.getPhone().add(p4);

      Session session = sessionFactory.openSession();
      session.beginTransaction();
      session.save(detail);
      session.getTransaction().commit();
      session.close();
   }
}