Analysis of the underlying technical principle of Spring ORM framework
Analysis of the underlying technical principle of Spring ORM framework
Introduction:
Spring Orem (Object-Relational Mapping) is a module used to support object relationship mapping in the Spring framework.It provides a way to interact with the database, maps the data in the relational database to the Java object, and provides the addition, deletion, deletion, and investigation operation of the database.This article will analyze the underlying technical principles of the Spring ORM framework and provide the corresponding Java code example.
Original analysis:
The Spring ORM framework is based on the Java Persistence API (JPA) technology and uses Hibernate as the default implementation.JPA is a set of API defined in the Java EE specification, which is used for object relationship mapping between Java applications and relational databases.By using JPA, Spring ORM can provide data access across multiple databases and easily switch the underlying ORM provider.
The core principle of the Spring ORM framework can be briefly summarized as follows:
1. Entity class mapping: By annotation or XML configuration, the Java physical class and database table are mapping to define the relationship between the physical class attributes and the table field.
Example code (using annotation configuration):
@Entity
@Table(name = "user")
public class User {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
@Column(name = "name")
private String name;
// Getters and setters
}
2. Affairs management: The Spring ORM framework provides support for transaction management. Through the boundaries of management transactions, the consistency and integrity of data operations are guaranteed.
Example code:
@Transactional
public void saveUser(User user) {
// Perform database operations
}
3. Data access object (DAO): Through the DAO interface definition and implementation, the data access operation is encapsulated as the method, and the database is provided to provide additional, deletion, and inspection operations.
Example code:
@Repository
public class UserDaoImpl implements UserDao {
@PersistenceContext
private EntityManager entityManager;
public void save(User user) {
entityManager.persist(user);
}
public User getById(Long id) {
return entityManager.find(User.class, id);
}
// Other CRUD methods
}
4. Query Language (JPQL): Spring ORM framework supports the use of JPQL query language for database query operations.JPQL is a query language that has nothing to do with specific databases and can be used directly in the application.
Example code:
public List<User> findByNameLike(String name) {
String jpql = "SELECT u FROM User u WHERE u.name LIKE :name";
TypedQuery<User> query = entityManager.createQuery(jpql, User.class);
query.setParameter("name", "%" + name + "%");
return query.getResultList();
}
5. Database connection management: The Spring ORM framework is responsible for managing database connections, and the performance and efficiency of database access are improved by connecting pools.
Example code (configured data source):
@Bean
public DataSource dataSource() {
DriverManagerDataSource dataSource = new DriverManagerDataSource();
dataSource.setDriverClassName("com.mysql.jdbc.Driver");
dataSource.setUrl("jdbc:mysql://localhost:3306/mydatabase");
dataSource.setUsername("root");
dataSource.setPassword("password");
return dataSource;
}
in conclusion:
The Spring ORM framework is based on JPA technology and Hibernate, which provides a simplified object relationship mapping solution.It realizes the core principles such as physical category mapping, transaction management, DAO interface, query language, and database connection management, and realizes efficient access and operations on the database.Developers can use the Spring ORM framework to quickly build a reliable and maintainable database access code.
I hope that the above -level technical principles of the Spring ORM framework will help you!
