Wayan | Kode Java - Learn Java by Examples

How do I create JLabel with an image icon?

By Wayan in Swing Last modified: May 21, 2023 5 Comments

To create a JLabel with an image icon we can either pass an ImageIcon as a second parameter to the JLabel constructor or use the JLabel.setIcon() method to set the icon.

package org.kodejava.swing;

import javax.swing.*;
import java.awt.*;
import java.util.Objects;

public class JLabelWithIcon extends JFrame {
    public JLabelWithIcon() throws HeadlessException {
        initialize();
    }

    private void initialize() {
        setSize(500, 500);
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        setLayout(new FlowLayout(FlowLayout.LEFT));

        Icon userIcon = new ImageIcon(
                Objects.requireNonNull(this.getClass().getResource("/images/user.png")));
        JLabel userLabel = new JLabel("Full Name :", userIcon, JLabel.LEFT);

        final ImageIcon houseIcon = new ImageIcon(
                Objects.requireNonNull(this.getClass().getResource("/images/house.png")));
        JLabel label2 = new JLabel("Address :", JLabel.LEFT);
        label2.setIcon(houseIcon);

        getContentPane().add(userLabel);
        getContentPane().add(label2);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> new JLabelWithIcon().setVisible(true));
    }
}

JLabel witch Image Icon

How do I create JLabel component?

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

package org.kodejava.swing;

import javax.swing.*;
import java.awt.*;

public class JLabelDemo extends JFrame {
    public JLabelDemo() throws HeadlessException {
        initialize();
    }

    private void initialize() {
        setSize(150, 300);
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        setLayout(new FlowLayout());

        // Create some JLabel with Texts and define the horizontal alignment
        JLabel label1 = new JLabel("Username :", JLabel.RIGHT);
        JLabel label2 = new JLabel("Password :", JLabel.RIGHT);
        JLabel label3 = new JLabel("Confirm Password :", JLabel.RIGHT);
        JLabel label4 = new JLabel("Remember Me!", JLabel.LEFT);
        JLabel label5 = new JLabel("Hello, Anybody There?", JLabel.CENTER);

        // Set the vertical alignment for label5 and also set a tool tip for it
        label5.setVerticalAlignment(JLabel.TOP);
        label5.setToolTipText("I have a tool tip with me!");

        getContentPane().add(label1);
        getContentPane().add(label2);
        getContentPane().add(label3);
        getContentPane().add(label4);
        getContentPane().add(label5);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> new JLabelDemo().setVisible(true));
    }
}

How do I use min, max, avg and sum Projections?

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

The code below demonstration the use of Projections.min(), Projections.max(), Projections.avg() and Projections.sum().

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.Projections;
import org.kodejava.hibernate.model.Track;

public class MinMaxAvgSumProjectionsDemo {
    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(Track.class)
                    .setProjection(Projections.max("duration"));
            Integer maxDuration = (Integer) criteria.uniqueResult();
            System.out.println("Max Track Duration = " + maxDuration);

            criteria.setProjection(Projections.min("duration"));
            Integer minDuration = (Integer) criteria.uniqueResult();
            System.out.println("Min Track Duration = " + minDuration);

            criteria.setProjection(Projections.avg("duration"));
            Double avgDuration = (Double) criteria.uniqueResult();
            System.out.println("Avg Track Duration = " + avgDuration);

            criteria.setProjection(Projections.sum("duration"));
            Long totalDuration = (Long) criteria.uniqueResult();
            System.out.println("Total Track Duration = " + totalDuration);
        }
    }
}

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 count the total records using Projections?

By Wayan in Hibernate Last modified: May 21, 2023 4 Comments

The example below show how to get total row count using the Projections.rowCount(). The result of this query will be a single object of Integer that contains the result of executing an SQL select count (*) command.

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.Projections;
import org.kodejava.hibernate.model.Track;

import java.util.List;

public class ProjectionsCountDemo {
    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)
                    .setProjection(Projections.rowCount());

            List<?> result = criteria.list();
            if (!result.isEmpty()) {
                Long rowCount = (Long) result.get(0);
                System.out.println("Total records: " + rowCount);
            }
        }
    }
}

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>

How do I create a pagination using Criteria?

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

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.hibernate;

import org.hibernate.SessionFactory;
import org.hibernate.Session;
import org.hibernate.HibernateException;
import org.hibernate.Criteria;
import org.hibernate.cfg.Configuration;
import org.kodejava.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(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 create a Criteria object?

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

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.hibernate;

import org.hibernate.SessionFactory;
import org.hibernate.Session;
import org.hibernate.HibernateException;
import org.hibernate.Criteria;
import org.hibernate.cfg.Configuration;
import org.kodejava.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 track : tracks) {
                System.out.println("Title     = " + track.getTitle());
                System.out.println("Artist    = " + track.getArtist().getName());
                System.out.println("Genre     = " + track.getGenre().getName());
                System.out.println("Record    = " + track.getRecord().getTitle());
                System.out.println("Label     = " + track.getRecord().getLabel().getName());
                System.out.println("-----------------------------------");
            }
        }
    }
}

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>