Maping of Set Collection with Hibernate 4.x

In Java java.util.Set is Hashtable based unordered collection not  allow duplicate entry. to mapping Set type collection  a separate table maintain to hold Set collection value and  foreign key used to map one object with multiple value of set collection for particular object .

suppose we have following Polyglot programmer can have do  programing  in multiple language .they can have  knowledge of multiple programing  language .
we can  map one polyglot programmer class object with multiple programing language  like following .

PolyglotProgramer .java

package in.jk.set.maping;

import java.util.Set;

 

import javax.persistence.CollectionTable;

import javax.persistence.Column;
import javax.persistence.ElementCollection;
import javax.persistence.Entity;
mport javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.Table;

@Entity
@Table(name="polyglot_programer")

public class PolyglotProgramer {

@Id

private String developerId;
private String developerName;
private String companyName;

@ElementCollection

@CollectionTable(name="Programing_langs" ,joinColumns=@JoinColumn(name="polyglotprogramer_developerid"))

@Column(name="language_name")
private Set<String> programingLanguages; 
  

 

public String getDeveloperId() {
return developerId;
}

public void setDeveloperId(String developerId) {

this.developerId = developerId;

 

}
 
 

public String getDeveloperName() {

return developerName;
}
public void setDeveloperName(String developerName) {

this.developerName = developerName;

 

}

public String getCompanyName() {

return companyName;

 

}

public void setCompanyName(String companyName) {

this.companyName = companyName;

 

}

public Sett<String> getProgramingLanguages() {

return programingLanguages;

 

}

public void setProgramingLanguages(Set<String> programingLanguages) {

this.programingLanguages = programingLanguages;

 

}

 

HibernateTest.java Class

 

package in.jk.list.maping;

import java.util.ArrayList;

import java.util.List;
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();
 

Set<String> programingLangsSet1= new HashSet<String>();

 

programingLangsSet1.add("Java");

programingLangsSet1.add("Java");
programingLangsSet1.add("Java script");programingLangsSet1.add("Python");

 

Set<String> programingLangSet2= new HashSet<String>();

 

programingLangSet2.add("Kotlin");

programingLangSet2.add("Kotlin");programingLangSet2.add("Kotlin");
programingLangSet2.add("Type Script");programingLangSet2.add("Scala");

PolyglotDeveloper developerJK = new PolyglotDeveloper();
developerJK.setDeveloperId("1");

developerJK.setDeveloperName("Johny Kumar");

developerJK.setCompanyName("SpaceX");

developerJK.setProgramingLanguages(programingLangSet1);

PolyglotDeveloper developerRAM = new PolyglotDeveloper();
developerRAM.setDeveloperId("2");

developerRAM.setDeveloperName("Ram");

developerRAM.setCompanyName("Tesla");

developerRAM.setProgramingLanguages(programingLangSet2);
 
session.persist(developerJK);

session.persist(developerRAM);
 
transaction.commit();

session.flush();
session.close();
System.out.println("Saved.............");
}
}

 

Hibernate.cgf.xml

<?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.set.maping.PolyglotProgramer" />

</session-factory>

</hibernate-configuration>

 

 

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

 

Ployglot_programer table

 

 

 

 

 

 

 

 

 

 

 

programing_langauage table ....

Note : table row not contain any duplicate data