Use the Hibernate Core Relocation framework in the Java Library for data persistence operation
Use the Hibernate Core RELOCATION framework for data persistence operation
Overview:
Hibernate Core Relocation is a powerful Java persistence framework that helps developers to simplify interaction with relational databases.It provides an object -oriented way to operate the database, mapped the object into the database table, reducing the needs of manually writing SQL statements.This article will introduce how to use the Hibernate Core Relocation framework for data persistence operation.
step:
Here are the steps to use Hibernate Core Relocation for data persistence:
1. Introduction dependencies:
First, the Hibernate Core RELOCATION dependencies are introduced in your Java project.You can add the following dependencies to Maven or Gradle configuration files:
Maven：
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
<version>5.5.7.Final</version>
</dependency>
Gradle：
implementation 'org.hibernate:hibernate-core:5.5.7.Final'
2. Create a physical class:
Create a physical class in your Java project, and the entity class is used to map to the database table.Each entity class should use the `@Entity` annotation for annotations, and use the only identifier attribute of the`@ID` annotation.
For example, create a physical class called `user`, which are mapped to the record in the` users` table:
@Entity
public class User {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private String name;
private String email;
// Construct function, Getter and Setter omit
}
3. Create Hibernate configuration file:
Create the `hibernate.cfg.xml` file in your Java project to configure Hibernate Core RELOCATION.The configuration file should contain the database connection information, and the path of the package where the physical class is located.
For example, the following is an example of a simple configuration file using the MySQL database:
<hibernate-configuration>
<session-factory>
<property name="hibernate.connection.driver_class">com.mysql.cj.jdbc.Driver</property>
<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/mydatabase</property>
<property name="hibernate.connection.username">root</property>
<property name="hibernate.connection.password">password</property>
<property name="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</property>
<property name="hibernate.hbm2ddl.auto">update</property>
<mapping class="com.example.User"/>
</session-factory>
</hibernate-configuration>
4. Create Hibernate session factory:
In your Java code, create a Hibernate session factory to interact with the database.You can use the `Configuration` class to read` hibernate.cfg.xml` configuration files, and use the method to build a session factory.
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
public class HibernateUtil {
private static final SessionFactory sessionFactory;
static {
try {
sessionFactory = new Configuration().configure().buildSessionFactory();
} catch (Throwable ex) {
throw new ExceptionInInitializerError(ex);
}
}
public static SessionFactory getSessionFactory() {
return sessionFactory;
}
}
5. Perform data persistence operation:
Now, you can use Hibernate Core Relocation for data persistence operations.First, get a Hibernate session object.Then, the use of transactions, submission, and rollback methods to manage operations.
Here are examples of using Hibernate Core Relocation to save and retrieve data:
import org.hibernate.Session;
import org.hibernate.Transaction;
public class Main {
public static void main(String[] args) {
// Get Hibernate session object
Session session = HibernateUtil.getSessionFactory().openSession();
// Create physical objects
User user = new User();
user.setName("John Doe");
user.setEmail("johndoe@example.com");
// Starting transaction
Transaction transaction = session.beginTransaction();
// Save the physical object
session.save(user);
// Submit a transaction
transaction.commit();
// Retrieve physical objects
User retrievedUser = session.get(User.class, user.getId());
System.out.println("Retrieved User: " + retrievedUser);
// Close the session
session.close();
}
}
This is a simple example that demonstrates how to use the Hibernate Core Relocation for data persistence operation.You can also use other functions provided by Hibernate, such as updates, delete and query.
in conclusion:
Using Hibernate Core RELOCATION can easily perform data persistence operations.It provides a simple way to map the object to the database table and perform various database operations.By following the above steps, you can start using the Hibernate Core Relocation and give full play to its powerful features.
