Understand and apply the Hibernate Commons Annotations framework technology in the Java library ES)

Understand and apply Hibernate Commons Annotations framework technology in the Java library Overview: Hibernate is an Object-Relational Mapping framework widely used in Java development, which provides a convenient method to map the object model into the relationship database.In Hibernate, we can use Hibernate Commons anymore framework to simplify the annotation configuration of the physical class.This article will introduce the basic concepts and usage methods of Hibernate Commons Annotations framework, and provide some Java code examples to help understand and apply the framework. Basic concept of Hibernate Commons Annotations framework: Hibernate Commons Annotations framework is a project that provides annotations for Hibernate.It can simplify the configuration by adding annotations to the physical class to avoid using the traditional XML configuration file.The most common annotations in the Hibernate Commons Annotations framework are @Entity, @Table, and @column. -@Entity: For identifying the physical class, tell hibernate this is a class mapped to the database table. -@Table: The name and other attributes for specifying the database table corresponding to the physical class. -@Column: The mapping relationship between the attributes and database tables in the physical class and the columns of the database table. How to use the Hibernate Commons Annotations framework: 1. Import Hibernate -related dependency package: Add Hibernate Commons Annotations to the project construction tool, such as Maven: Maven: <dependency> <groupId>org.hibernate</groupId> <artifactId>hibernate-commons-annotations</artifactId> <version>5.3.7.Final</version> </dependency> 2. Create a physical class and add annotations: import javax.persistence.Entity; import javax.persistence.Table; import javax.persistence.Column; @Entity @Table(name = "employees") public class Employee { @Column(name = "id") private int id; @Column(name = "name") private String name; // omit the definition of other attributes and methods } In the above example, the@Entity annotation identification. This class is a physical class.@Column annotation specifies the mapping relationship between the attributes and database tables in the physical class. 3. Use the API provided by Hibernate to run inquiries: import org.hibernate.Session; import org.hibernate.annotations.common.util.StandardClassLoaderDelegate; import org.hibernate.cfg.Configuration; public class Main { public static void main(String[] args) { Configuration configuration = new Configuration().configure(); Session session = configuration.buildSessionFactory().openSession(); Employee employee = session.get(Employee.class, 1); System.out.println("Employee ID: " + employee.getId()); System.out.println("Employee Name: " + employee.getName()); session.close(); } } In the above examples, we created a hibernate session and used the session.get () method to obtain information from the employee object from the database. Summarize: Through the Hibernate Commons Annotations framework, we can use simple annotations to configure the mapping relationship between the physical class and the database table, avoiding the traditional XML configuration, making the code more simple and easy to read.This article introduces the basic concepts and usage methods of Hibernate Commons Annotations framework, and provides related Java code examples.By learning and applying Hibernate Commons Annotations framework, we can more efficiently perform object -relationship mapping development.