jpa-hibernate

JPA/Hibernate quickstart

Jakarta Persistence API (JPA, formerly Java Persistence API) is a specification that allows Java applications to connect and consume databases and map Java objects to database tables. JPA is built on top of JDBC.

This Maven project shows the minimal configuration needed to connect to MariaDB databases using JPA.

LT;DR (kinda)

Add the JDBC Driver (check the latest version), JPA, and Hibernate (check the latest version):

<dependency>
    <groupId>org.mariadb.jdbc</groupId>
    <artifactId>mariadb-java-client</artifactId>
    <version>LATEST</version>
</dependency>
<dependency>
    <groupId>jakarta.persistence</groupId>
    <artifactId>jakarta.persistence-api</artifactId>
    <version>LATEST</version>
</dependency>
<dependency>
    <groupId>org.hibernate</groupId>
    <artifactId>hibernate-core-jakarta</artifactId>
    <version>LATEST</version>
</dependency>
<dependency>
    <groupId>org.glassfish.jaxb</groupId>
    <artifactId>jaxb-runtime</artifactId>
    <version>LATEST</version>
</dependency>

Configure a Persistence Unit with the database connection details:

<persistence xmlns="http://java.sun.com/xml/ns/persistence"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"
             version="2.0">
    <persistence-unit name="persistence-unit-name" transaction-type="RESOURCE_LOCAL">
        <properties>
            <property name="jakarta.persistence.jdbc.url" value="jdbc:mariadb://localhost:3306/database_name"/>
            <property name="jakarta.persistence.jdbc.user" value="user"/>
            <property name="jakarta.persistence.jdbc.password" value="Password123!"/>
        </properties>
    </persistence-unit>
</persistence>

Create an EntityManagerFactory using the configured Persistence Unit name:

public class Example {
    private static EntityManagerFactory emf;
    
    public Example() {
        emf = Persistence.createEntityManagerFactory("persistence-unit-name");
    }
}

Create an EntityManager and start a transaction to query the database:

EntityManager entityManager = emf.createEntityManager();
EntityTransaction transaction = entityManager.getTransaction();
transaction.begin();
boolean success = false;
try {
    ... use the entityManager here ...
        
    success = true;
    return returnValue;

} finally {
    if (success) {
        transaction.commit();
    } else {
        transaction.rollback();
    }
}

Requirements

• Java 21 or later. Previous versions should work (update the version in the pom.xml file). Apache Maven.
• MariaDB server.
• An SQL client tool like mariadb, DBeaver, or an SQL integration for your IDE.

Preparing the database

See the instructions here.

Running the app

Prepare the database:

CREATE DATABASE demo;
CREATE USER 'user'@'%' IDENTIFIED BY 'Password123!';
GRANT SELECT, INSERT, UPDATE, DELETE ON demo.* TO 'user'@'%';
GRANT DROP, CREATE on demo.* TO 'user'@'%';

USE demo;
CREATE TABLE programming_language(
	pl_id INT PRIMARY KEY AUTO_INCREMENT,
	pl_name VARCHAR(50) NOT NULL UNIQUE,
	pl_rating INT
);

Run the following in the command line:

git clone [email protected]:mariadb-developers/java-quickstart.git
cd java-quickstart/jpa-hibernate/
mvn package
java -jar target/jpa-hibernate-1.0-SNAPSHOT.jar

Check the output

You should see the output in the terminal.

You can also connect to the database and see the data in the programming_language table:

mariadb-shell --dsn mariadb://user:'Password123!'@127.0.0.1

Run the following query:

SELECT * FROM demo.programming_languages;

Tutorial

Read the tutorial or watch the video for detailed steps on how to implement this example from scratch: