The technical principles and best practice of the "Hibernate Commons Annotations" framework based on the Java class library

The technical principles and best practice of the "Hibernate Commons Annotations" framework based on the Java class library Overview: In Java development, using the Hibernate framework can greatly simplify the interactive process with the database.Hibernate Commons Annotations is part of the Hibernate framework, providing developers with a method of using annotations to maximize the relationship between the Java class and the database table, thereby making it more concise and easy to maintain. Technical principle: Hibernate Commons Annotions tells the Hibernate framework to database the Hibernate framework to the database by adding annotations to the Java class.It is based on the standard of Java's persistence API (JPA) and uses some common annotations, such as@Entity,@Table,@Column, etc. Best Practices: 1. Introduce Hibernate Commons Annotations Library: First of all, you need to introduce the Hibernate Commons Annotations library to the project dependence.You can use Maven or Gradle and other construction tools to manage these dependencies. 2. Create a physical class: Define the database table by creating a Java class.Use the @Entity annotation before the class name, indicating that this is a physical class corresponding to the database table. Code example: import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.Id; @Entity public class User { @Id @GeneratedValue private Long id; private String name; // omit the getter and setter method } 3. Define tables and columns: You can use @table and @column annotations to define table names and columns.By specifying the name property in the annotation, the table name and list can be customized. Code example: import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.Id; import javax.persistence.Table; @Entity @Table(name = "users") public class User { @Id @GeneratedValue private Long id; @Column(name = "user_name") private String name; // omit the getter and setter method } 4. Primary key generation strategy: Use @GENTEDVALUE annotations to define the primary key to generate strategy.Hibernate Commons Annotions provides some common generation strategies, such as self -growth and UUID. Code example: import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.Table; @Entity @Table(name = "users") public class User { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Long id; @Column(name = "user_name") private String name; // omit the getter and setter method } 5. Relations mapping: Use annotations to define the relationship between physical classes, such as one -to -one, one -to -many, more to many.You can define different types of relationships using@Onetoone,@Onetomany,@Manytoone,@Manytomany and other annotations. Code example: import javax.persistence.*; @Entity @Table(name = "users") public class User { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Long id; @Column(name = "user_name") private String name; @OneToOne @JoinColumn(name = "address_id") private Address address; // omit the getter and setter method } @Entity @Table(name = "addresses") public class Address { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Long id; private String street; // omit the getter and setter method } Through the above steps, you can use the Hibernate Commons Annotations to implement the mapping relationship between the Java class and the database table.The database operation can be used by calling the API of Hibernate, such as saving, updating, querying, etc. Summarize: Hibernate Commons Annotions is a way to simplify and optimize code. It uses the characteristics of the annotation to make the database operation more concise and easy to maintain.By using Hibernate Commons anymore, developers can focus more on the implementation of business logic without having to pay too much attention to the details of the database operation.