10 - Saving-Collections

@ElementCollection: It is used to save collection of elements

HibernateTest.java

package org.yash.hibernate;

import org.hibernate.Session;

import org.hibernate.SessionFactory;

import org.hibernate.cfg.Configuration;

import org.yash.dto.Address;

import org.yash.dto.UserDetails;

public class HibernateTest {

      public static void main(String args[]){

            UserDetails user = new UserDetails();

            user.setUserName("First User");

            UserDetails user2 = new UserDetails();

            user2.setUserName("Second User");

           

            Address addr1 = new Address();

            addr1.setCity("First City");

            addr1.setPincode("9999");

            addr1.setState("AB");

            addr1.setStreet("2355 SE Saint");

           

            Address addr2 = new Address();

            addr2.setCity("Second City");

            addr2.setPincode("7676");

            addr2.setState("AC");

            addr2.setStreet("2399 Hilton");

           

            user.getListOfAddresses().add(addr1);

            user.getListOfAddresses().add(addr2);

           

            SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();         

            Session session = sessionFactory.openSession();

            /* It is used to save all the objects and to define single unit of work */

            session.beginTransaction();

           

            session.save(user);

            //session.save(user2);

            session.getTransaction().commit();

           

            user = null;

           

            session = sessionFactory.openSession();

            session.beginTransaction();

            user = (UserDetails) session.get(UserDetails.class, 1);

            System.out.println("User name retrieved is "+user.getUserName());

      }

}

Address.java

package org.yash.dto;

import javax.persistence.Column;

import javax.persistence.Embeddable;

@Embeddable

public class Address {

      @Column(name="STREET_NAME")

      private String street;

      @Column(name="CITY_NAME")

      private String city;

      @Column(name="STATE_NAME")

      private String state;

      @Column(name="PIN_CODE")

      private String pincode;

     

      public String getStreet() {

            return street;

      }

      public void setStreet(String street) {

            this.street = street;

      }

      public String getCity() {

            return city;

      }

      public void setCity(String city) {

            this.city = city;

      }

      public String getState() {

            return state;

      }

      public void setState(String state) {

            this.state = state;

      }

      public String getPincode() {

            return pincode;

      }

      public void setPincode(String pincode) {

            this.pincode = pincode;

      }

     

}

UserDetails.java

package org.yash.dto;

import java.util.HashSet;

import java.util.Set;

import javax.persistence.ElementCollection;

import javax.persistence.Entity;

import javax.persistence.GeneratedValue;

import javax.persistence.GenerationType;

import javax.persistence.Id;

import javax.persistence.Table;

@Entity

@Table(name="USER_DETAILS")

public class UserDetails {

      /* @Id says "userId" is primary key */

      @Id @GeneratedValue (strategy=GenerationType.AUTO)

      private int userId;    

      private String userName;

      @ElementCollection

      private Set<Address> listOfAddresses = new HashSet<Address>();

     

      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;

      }

      public void setListOfAddresses(Set<Address> listOfAddresses) {

           this.listOfAddresses = listOfAddresses;

     }

     public Set<Address> getListOfAddresses() {

           return listOfAddresses;

     }

}

hibernate.cfg.xml

<?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="connection.driver_class">

            org.postgresql.Driver

        </property>

        <property name="connection.url">

            jdbc:postgresql://localhost:5433/hibernatedb

        </property>

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

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

        <!-- JDBC connection pool (use the built-in) -->

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

        <!-- SQL dialect -->

        <property name="dialect">

            org.hibernate.dialect.PostgreSQLDialect

        </property>

        <!-- Enable Hibernate's automatic session context management -->

        <property name="current_session_context_class">thread</property>

       

        <!-- Echo all executed SQL to stdout -->

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

       

        <!-- Drop and re-create the database schema on startup -->

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

<!-- create / update -->

   

       <!-- Names the annotated entity class -->

       <mapping class="org.yash.dto.UserDetails"/>   

    </session-factory>

</hibernate-configuration>