Criteria - Learn Java by Examples

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

By Wayan in Hibernate Last modified: May 23, 2023 0 Comment

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.hibernate;

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.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);
            }
        }
    }
}

Maven Dependencies

<dependencies>
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-core</artifactId>
        <version>5.6.9.Final</version>
    </dependency>
    <dependency>
        <groupId>com.mysql</groupId>
        <artifactId>mysql-connector-j</artifactId>
        <version>8.0.33</version>
    </dependency>
</dependencies>

How do I select a single record using Hibernate Criteria?

By Wayan in Hibernate Last modified: May 21, 2023 8 Comments

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.hibernate;

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.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());
            }
        }
    }
}

Maven Dependencies

<dependencies>
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-core</artifactId>
        <version>5.6.9.Final</version>
    </dependency>
    <dependency>
        <groupId>com.mysql</groupId>
        <artifactId>mysql-connector-j</artifactId>
        <version>8.0.33</version>
    </dependency>
</dependencies>

How do I set the fetch mode for Criteria association?

By Wayan in Hibernate Last modified: May 21, 2023 0 Comment

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

package org.kodejava.hibernate;

import org.hibernate.*;
import org.hibernate.cfg.Configuration;
import org.hibernate.criterion.Restrictions;
import org.kodejava.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.like("title", "The Beatles%"));

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

Maven Dependencies

<dependencies>
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-core</artifactId>
        <version>5.6.9.Final</version>
    </dependency>
    <dependency>
        <groupId>com.mysql</groupId>
        <artifactId>mysql-connector-j</artifactId>
        <version>8.0.33</version>
    </dependency>
</dependencies>

How do I order the Criteria query result set?

By Wayan in Hibernate Last modified: May 21, 2023 0 Comment

In this demo you’ll see how to order the result set 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.hibernate;

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.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());
            }
        }
    }
}

Maven Dependencies

<dependencies>
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-core</artifactId>
        <version>5.6.9.Final</version>
    </dependency>
    <dependency>
        <groupId>com.mysql</groupId>
        <artifactId>mysql-connector-j</artifactId>
        <version>8.0.33</version>
    </dependency>
</dependencies>

How do I add Restrictions to the Criteria object?

By Wayan in Hibernate Last modified: May 21, 2023 0 Comment

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 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.hibernate;

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.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 used 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.

Maven Dependencies

<dependencies>
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-core</artifactId>
        <version>5.6.9.Final</version>
    </dependency>
    <dependency>
        <groupId>com.mysql</groupId>
        <artifactId>mysql-connector-j</artifactId>
        <version>8.0.33</version>
    </dependency>
</dependencies>