Analysis of the technical principles of the persistence API framework in the Java class library

Analysis of technical principles of the persistent API framework in the Java class library Overview: In Java development, persistence is an important technology that can realize the long -term storage of data and make the data still exist after the application is restarted.There are many persistent API frameworks in the Java library, such as Hibernate, Spring Data JPA, etc.This article will analyze the technical principles of these commonly used API frameworks. 1. Hibernate technical analysis: Hibernate is a very popular Java persistence framework that can map the Java object to the table structure in the relationship database.Hibernate's technical principles mainly include the following aspects: 1. Object relationship mapping (ORM): Hibernate mapping the table in the relationship database through object relationship mapping.Developers only need to define the mapping relationship between the physical class and the database table (using annotations or XML configuration), and Hibernate can automatically generate SQL statements for developers to achieve data operation. 2. Session management: Hibernate manages database connections and session objects through sessionFactory.SessionFactory is a single -example object of a thread security that is used to create a connection with the database.Create SessionFactory when the application starts and close it at the end of the application.Through the session object, developers can perform CRUD operations and can save the modification of persistent objects into the database. 3. Caches Management: Hibernate provides first -level cache and second -level cache to improve performance.The first -level cache is the session level cache to cache the query results and persistence objects to improve the query performance.The second -level cache is the sessionFactory level cache, which is used to cache the entire persistence object to reduce interaction with the database. 4. Delay loading: Hibernate supports delay loading mechanism, that is, loading is only used when a certain attribute or associated object is really needed.This can improve query performance and avoid performance problems caused by loading a large amount of data at one time. Second, Spring Data JPA technical analysis: Spring Data JPA is a further package and extension of the Spring framework for JPA (Java Persistence API).JPA is a Java persistence standard that provides a set of APIs for managing databases.The technical principles of Spring Data JPA include the following aspects: 1. Warehouse interface: Spring Data JPA Uniform database operation by defining the warehouse interface.The warehouse interface inherits from the Jparepository interface, which provides a series of CRUD operation methods by default implementation.Developers only need to define the warehouse interface and provide them with the physical type and primary key type. Spring Data JPA can automatically generate data access implementation classes for the interface. 2. Dynamic implementation: Spring Data JPA provides a mechanism for dynamic query methods, which can be named by the dynamic query statement according to the method.For example, defining a method called FindByusername, Spring Data JPA will automatically analyze the method name and generate SQL statements that query the username. 3. Note configuration: Spring Data JPA supports the mapping relationship between the physical class and the database table.For example, using the @Entity annotation marker entity class, using the specified table name and field name with @table annotation. 4. Affairs management: Spring Data JPA and Spring framework are perfectly integrated. You can use Spring's transaction management mechanism to manage database transactions.Open transaction management through the @EnabletransactionManagement annotation, and mark the @Transactions annotation on the method that requires transaction control to achieve transaction management of database operations. Conclusion: The above is the analysis of the technical principles of the persistent API framework in the Java library.Whether it is Hibernate or Spring Data JPA, they have their own advantages and characteristics in terms of durable.By understanding the technical principles of these persistent frameworks, developers can better choose and use frameworks that are suitable for their own project needs to improve development efficiency and code quality. Note: This article only introduces the technical principles of the persistent API framework. If a complete programming code and related configuration are required, please refer to the official documents or other information of each framework.