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The UJO ORM framework is an object relationship mapping tool used in the Java class library. It allows developers to simplify database operations to improve development efficiency.This article will explore the technical principles of the UJO ORM framework in the Java class library and provide some related Java code examples. 1. What is an object relationship mapping (ORM)? Object -relationship mapping (ORM) is a technology that converts the object model and the relationship database model.Through ORM, developers can operate the database in an object -oriented way without writing SQL statements directly.The ORM framework can automatically map the Java object to the database table and provide various methods to perform CRUD operations. Second, the characteristics of the UJO ORM framework 1. Simplified database operation: The UJO ORM framework provides a set of simple and powerful APIs. Developers can easily perform database operations through these APIs, such as saving, updating, deleting and querying. 2. Easy to use: The UJO ORM framework adopts a simple and easy -to -understand design concept, so that developers can quickly use and use it.It provides good documentation and example code for the convenience of developers' reference and learning. 3. Cross -database support: UJO ORM framework supports multiple databases, including MySQL, Oracle, Postgresql, etc.Developers can choose the appropriate database to develop and deploy according to their needs. Third, the technical principle of the UJO ORM framework 1. Note drive: UJO ORM framework uses annotations to mark the mapping relationship between Java class and attributes and database tables and fields.By adding @entity annotations to the Java class, the Java class can be mapped as a database table.At the same time, the @Column annotation can map the attributes of the Java class as the field of the database table. Example: @Entity @Table(name = "user") public class User { @Id @Column(name = "id") private int id; @Column(name = "name") private String name; // omit the getter and setter method } 2. Affairs management: UJO ORM framework supports transaction management to ensure the consistency and reliability of database operations.By adding @transactional annotations to the method, this method can be packed in one transaction.If the method is successful, the transaction will be submitted automatically; if the method execution fails, the transaction will be rolled back. Example: @Transactional public void saveUser(User user) { // Execute the database operation } 3. Database connection management: The UJO ORM framework provides a connection pool to manage the database connection.The connection pool can be reused to use the overhead created and destroyed the connection when the database is operated, and the performance is improved. Example: @Configuration public class DatabaseConfig { @Bean public DataSource dataSource() { // Configure the connection pool HikariConfig config = new HikariConfig(); config.setJdbcUrl("jdbc:mysql://localhost:3306/mydb"); config.setUsername("username"); config.setPassword("password"); return new HikariDataSource(config); } } Fourth, summary By using the UJO ORM framework, developers can simplify database operations and can better use object -oriented thinking for development.This article introduces the technical principles of the UJO ORM framework in the Java class library, including annotations, transaction management, and database connection management.Through in -depth understanding of these technical principles, developers can better use the UJO ORM framework for development.