Hibernate Component Mapping Using Annotations Part -2

The @Embedded annotation is used to specify the Address entity should be stored in the STUDENTtable as a component.

@Embeddable annotation is used to specify the Address class will be used as a component. TheAddress class cannot have a primary key of its own, it uses the enclosing class primary key.

package com.vaannila.student;

 

import javax.persistence.Column;

import javax.persistence.Embeddable;

 

@Embeddable

public class Address {

 

private String street;

private String city;

private String state;

private String zipcode;

 

public Address() {

}

 

public Address(String street, String city, String state, String zipcode) {

this.street = street;

this.city = city;

this.state = state;

this.zipcode = zipcode;

}

 

@Column(name = "ADDRESS_STREET", nullable = false, length=250)

public String getStreet() {

return this.street;

}

 

public void setStreet(String street) {

this.street = street;

}

 

@Column(name = "ADDRESS_CITY", nullable = false, length=50)

public String getCity() {

return this.city;

}

 

public void setCity(String city) {

this.city = city;

}

 

@Column(name = "ADDRESS_STATE", nullable = false, length=50)

public String getState() {

return this.state;

}

 

public void setState(String state) {

this.state = state;

}

 

@Column(name = "ADDRESS_ZIPCODE", nullable = false, length=10)

public String getZipcode() {

return this.zipcode;

}

 

public void setZipcode(String zipcode) {

this.zipcode = zipcode;

}

 

}

Now create the hibernate configuration file and add the Student and Address classes.

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE hibernate-configuration PUBLIC

"-//Hibernate/Hibernate Configuration DTD 3.0//EN"

"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<hibernate-configuration>

<session-factory>

<property name="hibernate.connection.driver_class"> org.hsqldb.jdbcDriver</property>

<property name="hibernate.connection.url"> jdbc:hsqldb:hsql://localhost<;/property>

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

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

<property name="connection.pool_size">1</property>

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

<property name="show_sql">true</property>

<property name="hbm2ddl.auto">create-drop</property>

<mapping class="com.vaannila.student.Student" />

<mapping class="com.vaannila.student.Address" />

</session-factory>

</hibernate-configuration>

Create the Main class to run the example.

package com.vaannila.student;

 

import org.hibernate.HibernateException;

import org.hibernate.Session;

import org.hibernate.Transaction;

 

import com.vaannila.util.HibernateUtil;

 

public class Main {

 

public static void main(String[] args) {

Session session = HibernateUtil.getSessionFactory().openSession();

Transaction transaction = null;

try {

transaction = session.beginTransaction();

Address address = new Address("OMR Road", "Chennai", "TN","600097");

Student student = new Student("Eswar", address);

session.save(student);

transaction.commit();

} catch (HibernateException e) {

transaction.rollback();

e.printStackTrace();

} finally {

session.close();

}

 

}

 

}