Mapping of Value Type Object by making Object Embedable in Hibernate 4.x

In Hibernate we can map a java object by two way .
1. Value type :- by marking class  @Embeddable annotation ;
2. Entity type :- by marking class  @Entity annotation ;

Both of above technique used association to associate one java class to another java class .


Difference between  Value type  and  Entity type mapping

Value type used aggregation a weak form of association in which life cycle of value type object is not dependent on in which it associate (embed) . on other hand Entity Type is used composition to associate object . in case composition  object is tightly coupled and object life cycle is completely dependent on object in which it is composite.

Note : In Value type Object mapping in database table value type object(Embeddable) object property embedded in same table there is  no separate table value type object .

To mapping a Value type object we need following file .

Step 1 . Create Hibernate.cfg.xml configuration file .
Step 2 . Create Hibernate Entity  which Employee.java
Step 2 . Create Embeddable  class which is Adreess.java
Step 3 . Create  Main class to create session  and create java object . and persist class .




Hibernate.cfg.xml  : contain various configuration property like database driver name ,database url
                                 user name and password and all mapping class .

<?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.show_sql">true</property>

<property name="hbm2ddl.auto">update</property>
<property name="hibernate.dialect">org.hibernate.dialect.ProgressDialect</property>
<property name="hibernate.connection.driver_class">org.postgresql.Driver</property>
<!-- Assume hibernate is the database name -->

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

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

<property name="hibernate.connection.password">postgres</property>

<mapping class="in.jk.embed.Employee" />

</session-factory>

</hibernate-configuration>


 

Step 2 Create Hibernate Entity java Class :

To Create java persistent class just create simple plain java class  and decorated minimum two annotation

@Entity for mark java class  hibernate entity and @Id  to mark field for primary key .  also create Address class reference in Employee class

package in.jk.embed;

import javax.persistence.Entity;
import javax.persistence.Id;

@Entity

public class Employee {

 

@Id

private int empId;

private String emapName;

private String companyName;

 

@embedded  // this annotation is optional
private Address address;

public int getEmpId() {
return empId;
}

public void setEmpId(int empId) {
this.empId = empId;
}

public String getEmapName() {
return emapName;

}

public void setEmapName(String emapName) {
this.emapName = emapName;
}
public String getCompanyName() {
return companyName;
}
public void setCompanyName(String companyName) {
this.companyName = companyName;
}
public Address getAddress() {
return address;
}
public void setAddress(Address address) {
this.address = address;
}
}

 

 

Step 3 .  Create value type class (Embeddable  class )  by marking  class @Embeddable annotation  .

 

Adreess.java

 

package in.jk.embed;

import javax.persistence.Embeddable;

 

 

 

@Embeddable

public class Address {

 

private String flatNo;

private String streetName;

private String cityName;

private String pincode;

private String stateName

public String getFlatNo() {

return flatNo;

 

}

public void setFlatNo(String flatNo) {

this.flatNo = flatNo;

 

}

public String getStreetName() {

return streetName;

 

}

public void setStreetName(String streetName) {

this.streetName = streetName;

 

}

public String getCityName() {

return cityName;

 

}

public void setCityName(String cityName) {

this.cityName = cityName;

 

}

public String getPincode() {

return pincode;

 

}

public void setPincode(String pincode) {

this.pincode = pincode;

 }

 

public String getStateName() {

return stateName;

}

public void setStateName(String stateName) {

this.stateName = stateName;

 

}

 

Step  Create a main class to persist class : To persistent a java object with hibernate we have require Configuration object  , SessionFactory object and session object .

 

import org.hibernate.Session;

import org.hibernate.SessionFactory;

import org.hibernate.Transaction;

import org.hibernate.cfg.Configuration;

import org.hibernate.service.ServiceRegistry;

import org.hibernate.service.ServiceRegistryBuilder;

 

public class HibernateTest {

 

public static void main(String[] args) {

 

Configuration configuration = new Configuration(); //  

configuration.configure("hibernate.cfg.xml");

ServiceRegistry serviceRegistry = new ServiceRegistryBuilder().applySettings(configuration.getProperties())

 buildServiceRegistry();

SessionFactory sessionFactory = configuration.buildSessionFactory(serviceRegistry);

 

Session session = sessionFactory.openSession();

Transaction transaction = session.beginTransaction();

Address addressJK = new Address();

addressJK.setFlatNo("44/45");

addressJK.setStreetName("Loyal Line ");
ddressJK.setCityName("Noida");
ddressJK.setStateName("Uttar Pradesh");
addressJK.setPincode("251201");

Address addressRam = new Address();

addressRam.setFlatNo("55/45");
addressRam.setStreetName("Railways Line ");
addressRam.setCityName("Ghaziabad");
addressRam.setStateName("Uttar Pradesh");
addressRam.setPincode("251155");

Employee employeeJK= new Employee();

employeeJK.setEmpId(1);

employeeJK.setCompanyName("Johny kumar");

employeeJK.setCompanyName("Google.com");
employeeJK.setAddress(addressJK);

 

Employee employeeRam = new Employee();

employeeRam .setEmpId(2);

employeeRam .setCompanyName("Ram");

employeeRam .setCompanyName("Amazon");
employeeRam.setAddress(addressRam);

 session.persist(employeeJK);

session.persist(employeeRam );

 

transaction.commit();

session.flush();

 

session.close();

System.out.println("Saved.............");

}

}

 


In Database table data look like this ......

 

 

 

 

 

 

 

 

 

 

 

 

 ;