Transparent persistence is provided for Plain old Java objects or POJOs. For proper functioning of the applications importance should be given to the methods equals () and hash Code methods (). It has a requirement which should be strictly followed in the applications which is a no-argument constructor.
In the context of Hibernate and transparent persistence, it refers to the ability of Hibernate to manage the persistence of Java objects to a relational database without the need for the developer to write explicit code for database operations. Transparent persistence is one of the key features of Hibernate, making it an Object-Relational Mapping (ORM) framework.
Here’s an explanation of transparent persistence in Hibernate:
- Object-Relational Mapping (ORM): Hibernate provides a mechanism to map Java objects to database tables and vice versa. This mapping is defined in XML files or annotations, and it allows developers to work with Java objects in their application code while Hibernate takes care of the underlying database interactions.
- Automatic Persistence: When you work with Hibernate, you don’t need to write explicit SQL queries or JDBC code to perform basic database operations like insertion, updating, or deletion. Hibernate automatically generates the SQL statements based on the mapping configurations and executes them on the database.
- Session Management: In Hibernate, a
Session
is used to interact with the database. TheSession
acts as a bridge between the Java application and the database. It tracks changes made to the Java objects and synchronizes them with the database when necessary. - Dirty Checking: Hibernate employs a mechanism known as “dirty checking” to determine which objects have been modified. When a transaction is committed or when necessary, Hibernate checks for changes in the objects associated with the current session and automatically generates the appropriate SQL statements to synchronize the changes with the database.
- Caching: Hibernate includes a caching mechanism to improve performance. It can cache both the Java objects and the database query results, reducing the number of database calls and improving overall application performance.
In summary, transparent persistence in Hibernate simplifies the interaction between Java applications and relational databases by automatically handling the conversion of Java objects to database records and vice versa. Developers can focus on working with objects in their application code without being overly concerned about the underlying database operations.