The technical principle of the Spring ORM framework in the Java library in the Java library
The technical principle of the Spring ORM framework in the Java library in the Java library
introduction:
The Spring ORM framework is an important part of the Spring framework, which is used to simplify the interaction between Java applications and relational databases.It provides a set of efficient and flexible technologies that enable developers to persist Java objects into databases through object -relationship mapping (ORM).
1. Overview of ORM:
ORM is a programming technology that gives the data conversion work between the relational database and the object -oriented programming language to a middleware.By mapping the relationship between the Java class and the database table, the ORM framework simplifies the workload of developers in writing SQL statements and provides more intuitive programming methods.
The characteristics of the Spring ORM framework:
1. Simplify data access:
The Spring ORM framework provides a unified data access interface that allows developers to access different databases in the same way.Developers can directly embed the SQL statement into the Java code, or they can also use object relationship mapping. By defining the mapping relationship between the physical class and the database table, the data is durable.
2. Support multiple ORM implementation:
The Spring ORM framework not only supports Hibernate as ORM, but also supports other popular ORM frameworks, such as Mybatis and JPA.Developers can choose suitable ORM implementation according to the project.
3. Affairs management:
The Spring ORM framework provides the function of transaction management. It can define the boundaries of transaction through annotations or programming to ensure the consistency and integrity of the data.
Third, technical principles of Spring ORM framework:
The technical principles of the Spring ORM framework mainly include the following aspects:
1. Data source configuration:
Through configuration files in Spring, developers can define some attributes of database connection information and connecting pools, such as database drives, connecting URLs, user names, passwords, etc.The Spring ORM framework can obtain the database connection based on these configuration information in order to interact with the database.
2. Object relationship mapping:
The Spring ORM framework uses the object relationship mapping technology to mappore the records of the Java object and the database table.Developers can use annotations or XML configurations to define the mapping relationship between physical classes and database tables, including table names, field names, primary keys, external keys, and associated relationships.
3. Affairs management:
The Spring ORM framework provides the function of transaction management, which can declare the transaction boundary through annotations or programming methods in the business method.The Spring ORM framework will automatically manage the start, submission or return of the transaction management strategy according to the configuration transaction management strategy, and ensure the consistency and integrity of the data.
The Spring ORM framework is encapsulated and processed with abnormalities in the underlying database operation.Developers can handle the abnormalities provided by the Spring ORM framework for corresponding treatment, such as rollback transactions or record log information.
Java code example:
The following example demonstrates the code fragment of data persistent operation using the Spring ORM framework.
1. Configure data source:
@Configuration
public class DataSourceConfig {
@Bean
public DataSource dataSource() {
BasicDataSource dataSource = new BasicDataSource();
dataSource.setDriverClassName("com.mysql.jdbc.Driver");
dataSource.setUrl("jdbc:mysql://localhost:3306/mydatabase");
dataSource.setUsername("username");
dataSource.setPassword("password");
return dataSource;
}
}
2. Define the physical class:
@Entity
@Table(name = "user")
public class User {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private String username;
private String password;
// omit the getter and setter method
}
3. Declarize transaction boundary:
@Service
@Transactional
public class UserService {
@Autowired
private UserRepository userRepository;
public void saveUser(User user) {
userRepository.save(user);
}
}
4. Data access interface:
public interface UserRepository extends JpaRepository<User, Long> {
// omit other methods
}
The above sample code demonstrates how the data persistence operation is performed through the Spring ORM framework.Developers can access the interface using @RePOSITORY annotation markers. By inheriting the Jparepository interface, the Spring ORM framework will automatically implement the CRUD operation method.
in conclusion:
The technical principles of the Spring ORM framework in the Java library mainly include data source configuration, object relationship mapping, transaction management, and abnormal processing.By using the Spring ORM framework, developers can simplify the interaction between Java applications and relational databases and improve development efficiency and code quality.
