Learn about the core technical principles and advantages of the core technical principles and advantages of the "Hibernate Commons Annotations" framework in the Java library
Hibernate Commons Anotations is a framework developed by the Hibernate project development team to simplify and standardize Java persistence programming.It is based on the Java standard's persistence specifications of JPA (Java Persistence API) and provides a set of reusable annotations to describe the mapping relationship between the Java class and attributes and database tables and columns.
The core technical principle of the Hibernate Commons Annotions is to define the mapping relationship between the entity class (Entity) and the database table by using annotations.Developers can use annotations to indicate which attributes are the persistent attributes of the physical class, and how to correspond to the columns of these attributes to the database table.The Hibernate framework dynamically generates SQL statements based on these annotations, thereby achieving persistent operations.
The advantages of Hibernate Commons Annotations are as follows:
1. Simplify development: Using Hibernate Commons Annotations, developers can describe the mapping relationship between the physical class and the database table through simple annotations, rather than the XML configuration file.This greatly simplifies the development process and reduces the workload of writing the lengthy XML configuration file.
2. Standardization: Hibernate Commons Annotations follows the JPA specifications, providing a set of standardized annotations, which is compatible with other frameworks to implement JPA.This allows developers to easily switch different implementation without changing a large number of code.
3. High performance: Hibernate Commons Annotions dynamically generates SQL statements to reduce the workload of developers manually writing SQL.In addition, Hibernate has improved execution efficiency, reduced the number of database access, and improves system performance by using cache and delay loading technologies.
Below is a sample code using Hibernate Commons Annotations:
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
@Entity
public class Employee {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private int id;
private String name;
private double salary;
// Getters and setters
}
// Use hibernate for persistent operation
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
public class Main {
public static void main(String[] args) {
// Create sessionFactory
Configuration configuration = new Configuration().configure();
SessionFactory sessionFactory = configuration.buildSessionFactory();
// Create session
Session session = sessionFactory.openSession();
// Open transaction
session.beginTransaction();
// Create physical objects
Employee employee = new Employee();
employee.setName("John Doe");
employee.setSalary(1000);
// The persistent object
session.save(employee);
// Submit a transaction
session.getTransaction().commit();
// Turn off session and sessionFactory
session.close();
sessionFactory.close();
}
}
In the above example code, the @entity annotation is used to identify the Employee class as a physical class.@ID annotation is used to identify the ID attribute is the unique logo of the Employee entity.By calling the session.save () method, the Employee object can be persisted to the database.
In summary, Hibernate Commons Annotions is a powerful, simplified and standardized Java persistence programming framework.It describes the mapping relationship between the Java class and the database table, simplifies the development process, and improves development efficiency and system performance.It is an important technology in Java's persistent programming.
