How do I use Hibernate’s Restriction.in criterion?

This example demonstrate the use of Hibernate’s Restriction.in criterion. This restriction will query for some record based on a collection of parameter defined for a specific property of the bean.

package org.kodejava.example.hibernate.criteria;

import org.hibernate.SessionFactory;
import org.hibernate.Session;
import org.hibernate.HibernateException;
import org.hibernate.Criteria;
import org.hibernate.cfg.Configuration;
import org.hibernate.criterion.Restrictions;
import org.kodejava.example.hibernate.model.Genre;

import java.util.List;

public class RestrictionInDemo {
    public static Session getSession() throws HibernateException {
        String cfg = "hibernate.cfg.xml";
        SessionFactory sessionFactory = new Configuration().configure(cfg)
            .buildSessionFactory();
        return sessionFactory.openSession();
    }

    @SuppressWarnings("unchecked")
    public static void main(String[] args) {
        try (Session session = getSession()) {
            // Create a Criteria an add an in constraint for the property
            // id. This in restrictions will return genre with id 1, 2, 3
            // and 4.
            Criteria criteria = session.createCriteria(Genre.class)
                .add(Restrictions.in("id", 1L, 2L, 3L, 4L));

            List<Genre> result = criteria.list();
            for (Genre genre : result) {
                System.out.println(genre);
            }
        }
    }
}

How do I select a single record using Hibernate Criteria?

The Criteria.uniqueResult() method make it easier to query a single instance of a persistence object. When no persistence found this method will return a null value.

package org.kodejava.example.hibernate.criteria;

import org.hibernate.Criteria;
import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import org.hibernate.criterion.Restrictions;
import org.kodejava.example.hibernate.model.Genre;

public class UniqueResultExample {
    public static Session getSession() throws HibernateException {
        String cfg = "hibernate.cfg.xml";
        SessionFactory sessionFactory = new Configuration().configure(cfg)
            .buildSessionFactory();
        return sessionFactory.openSession();
    }

    public static void main(String[] args) {
        try (Session session = getSession()) {
            Criteria criteria = session.createCriteria(Genre.class)
                .add(Restrictions.eq("id", 1L));

            // Convenience method to return a single instance that matches
            // the query, or null if the query returns no results.
            Object result = criteria.uniqueResult();
            if (result != null) {
                Genre genre = (Genre) result;
                System.out.println("Genre = " + genre.getName());
            }
        }
    }
}

How do I set the fetch mode for Criteria association?

To set the fetching mode for association we can call the Criteria‘s setFetchMode() method. We can user the FetchMode.SELECT or FetchMode.JOIN.

package org.kodejava.example.hibernate.criteria;

import org.hibernate.*;
import org.hibernate.cfg.Configuration;
import org.hibernate.criterion.Restrictions;
import org.kodejava.example.hibernate.model.Record;

import java.util.List;

public class FetchModeDemo {
    public static Session getSession() throws HibernateException {
        String cfg = "hibernate.cfg.xml";
        SessionFactory sessionFactory = new Configuration().configure(cfg)
            .buildSessionFactory();
        return sessionFactory.openSession();
    }

    @SuppressWarnings("unchecked")
    public static void main(String[] args) {
        try (Session session = getSession()) {
            Criteria criteria = session.createCriteria(Record.class)
                .setFetchMode("artist", FetchMode.SELECT)
                .setFetchMode("label", FetchMode.SELECT)
                .add(Restrictions.eq("title", "Please Please Me"));

            List<Record> records = criteria.list();
            for (Record record : records) {
                System.out.println("Recording  = " 
                    + record.getTitle());
                System.out.println("Artist     = " 
                    + record.getArtist().getName());
            }
        }
    }
}

How do I order the Criteria query resultset?

In this demo you’ll see how to order the resultset of out Criteria query. It can be done by adding the org.hibernate.criterion.Order into the Criteria object and we can either order the result in ascending or descending order.

package org.kodejava.example.hibernate.criteria;

import org.hibernate.SessionFactory;
import org.hibernate.Session;
import org.hibernate.HibernateException;
import org.hibernate.Criteria;
import org.hibernate.cfg.Configuration;
import org.hibernate.criterion.Order;
import org.kodejava.example.hibernate.model.Track;

import java.util.List;

public class CriteriaOrderDemo {
    public static Session getSession() throws HibernateException {
        String cfg = "hibernate.cfg.xml";
        SessionFactory sessionFactory = new Configuration().configure(cfg)
            .buildSessionFactory();
        return sessionFactory.openSession();
    }

    @SuppressWarnings("unchecked")
    public static void main(String[] args) {
        try (Session session = getSession()) {
            Criteria criteria = session.createCriteria(Track.class)
                .addOrder(Order.asc("title"))
                .setFirstResult(0)
                .setMaxResults(10);

            List<Track> tracks = criteria.list();
            for (Track track : tracks) {
                System.out.println("Track = " + track.getTitle());
            }
        }
    }
}

How do I add Restrictions to the Criteria object?

In this example you’ll learn how to add restrictions to the Criteria object. Using restriction we can narrow the result of our query. In the code below we add some restrictions such as Restrictions.eq(), Restrictions.like() and Restrictions.isNotNull().

In the Hibernate framework you’ll find a lot of class the use a method chaining. As in the example below you can see that we actually can add an endless restrictions by calling the add() method.

package org.kodejava.example.hibernate.criteria;

import org.hibernate.SessionFactory;
import org.hibernate.Session;
import org.hibernate.HibernateException;
import org.hibernate.Criteria;
import org.hibernate.criterion.Restrictions;
import org.hibernate.cfg.Configuration;
import org.kodejava.example.hibernate.model.Track;

import java.util.List;

public class RestrictionsDemo {
    public static Session getSession() throws HibernateException {
        String cfg = "hibernate.cfg.xml";
        SessionFactory sessionFactory = new Configuration().configure(cfg)
            .buildSessionFactory();
        return sessionFactory.openSession();
    }

    @SuppressWarnings("unchecked")
    public static void main(String[] args) {
        try (Session session = getSession()) {
            Criteria criteria = session.createCriteria(Track.class)
                .createAlias("artist", "artist")
                .createAlias("genre", "genre")
                .add(Restrictions.eq("title", "Ob-La-Di, Ob-La-Da"))
                .add(Restrictions.like("artist.name", "%beatles%"))
                .add(Restrictions.isNotNull("genre.name"));

            List<Track> tracks = criteria.list();
            for (Track track : tracks) {
                System.out.println("Track = " + track.getTitle() +
                    "; Artist = " + track.getArtist().getName() +
                    "; Genre = " + track.getGenre().getName());
            }
        }
    }
}

Here are some other restrictions that can also be use to narrow our Criteria query result, for a complete restrictions you can see the Restrictions class documentation.

  • Restrictions.ne("title", "Twist and Shout") – Apply a “not equal” constraint to the named property.
  • Restrictions.ilike("title", "Twist%") – A case-insensitive “like”.
  • Restrictions.isNull("title") – Apply an “is null” constraint to the named property.
  • Restrictions.gt("duration", new Integer(200)) – Apply a “greater than” constraint to the named property.
  • Restrictions.between("duration", new Integer(100), new Integer(200)) – Apply a “between” constraint to the named property
  • Restrictions.or(criterionA, criterionB) – Return the disjunction of two expressions.
  • Restrictions.disjuction() – Group expressions together in a single disjunction.

How do I create a pagination using Criteria?

To create a pagination or limit the result set returned by the Criteria query we can use the setFirstResult() and setMaxResults() method. The setFirstResult() method defines the first row to start with and the setMaxResults() method defines the maximum number of records to read. Let’s see the demo below.

package org.kodejava.example.hibernate.criteria;

import org.hibernate.SessionFactory;
import org.hibernate.Session;
import org.hibernate.HibernateException;
import org.hibernate.Criteria;
import org.hibernate.cfg.Configuration;
import org.kodejava.example.hibernate.model.Track;

import java.util.List;

public class CriteriaPagingDemo {
    public static Session getSession() throws HibernateException {
        String cfg = "hibernate.cfg.xml";
        SessionFactory sessionFactory = new Configuration().configure(cfg)
            .buildSessionFactory();
        return sessionFactory.openSession();
    }

    @SuppressWarnings("unchecked")
    public static void main(String[] args) {
        try (Session session = getSession()) {
            Criteria criteria = session.createCriteria(Track.class);

            // Set the first record index to read from the result set.
            criteria.setFirstResult(0);
            // Set the maximum number of records to read
            criteria.setMaxResults(2);

            List<Track> tracks = criteria.list();
            for (Track track : tracks) {
                System.out.println("Track = " + track.getTitle());
            }
        }
    }
}

How do I create a Criteria object?

This example show you how to create an instance of Hibernate Criteria class. To create a Criteria we call the factory method of the Session object and pass the persistence class as parameter. To execute the Criteria query we simply call the list() method.

package org.kodejava.example.hibernate.criteria;

import org.hibernate.SessionFactory;
import org.hibernate.Session;
import org.hibernate.HibernateException;
import org.hibernate.Criteria;
import org.hibernate.cfg.Configuration;
import org.kodejava.example.hibernate.model.Track;

import java.util.List;

public class CreateCriteriaDemo {
    public static Session getSession() throws HibernateException {
        String cfg = "hibernate.cfg.xml";
        SessionFactory sessionFactory = new Configuration().configure(cfg)
            .buildSessionFactory();
        return sessionFactory.openSession();
    }

    @SuppressWarnings("unchecked")
    public static void main(String[] args) {
        try (Session session = getSession()) {
            // Create a new Criteria to query for a collection of Tracks.
            // To create an instance of Criteria we call a createCriteria()
            // factory method of the Session object.
            Criteria criteria = session.createCriteria(Track.class);

            // Call the list() method to retrieve a collections of Tracks
            // from the database.
            List<Track> tracks = criteria.list();

            for (Track t : tracks) {
                System.out.println("Title     = " + t.getTitle());
                System.out.println("Artist    = " + t.getArtist().getName());
                System.out.println("Genre     = " + t.getGenre().getName());
                System.out.println("Record    = " + t.getRecord().getTitle());
                System.out.println("Label     = " + t.getRecord().getLabel().getName());
                System.out.println("-----------------------------------");
            }
        }
    }
}