What Is Hibernate Framework?
Hibernate Framework is a free open source object-relational mapping library for java which is designed to map objects to RDBMS and to implement the object-oriented programming concepts in relational database. Hibernate frameworkThe Hibernate architecture is minimally designed and it created a layer between the application and the database. All detailed like mapping, database connecting strings, entity classes and all other details are loaded, and a synchronization is created between the database and the application by Hibernate.
Hibernate database is strong and secure too, and can be used in a number of ways. That’s why our programmers also used Hibernate framework with carefully designed and developed Hibernate annotations to make your database safe and secure.
Hibernate Framework Architecture
Hibernate has a layered architecture which helps the user to operate without having to know the underlying API’s. Hibernate framework architecture includes many objects such as persistent object, session factory, transaction factory, connection factory, session, transaction etc.
Hibernate uses various existing Java APIs, like JDBC, Java Transaction API (JTA), and Java Naming and Directory Interface (JNDI). JDBC provides a rudimentary level of abstraction of functionality common to relational database, allowing almost any database with a JDBC driver to be supported by Hibernate. JNDI and JTA allow. Hibernate to be integrated with J2EE application server.
Elements of Hibernate Architecture
Before creating the hibernate application, we must know about the elements of hibernate architecture.
Configuration: The configuration object is the first hibernate object you create in any hibernate application. It is usually created only once during application initialization. It represents a configuration or properties file required by the Hibernate.
Session Factory: The Session Factory is a factory of sessions and clients of connection provider. It holds second level cache of data. The org.hibernate.sessionfactory interface method to get the object of Session.
Session: The session object provides an interface between the application and data stored in the database. It is a short-lived object and wraps the JDBC connection. Session interface provides methods to insert , update and delete the object.
Transaction: The transaction object specifies the atomic unit of work. It is optional. The org.hibernate.transaction interface provides methods for transaction management.
Query objects: query objects use SQL or Hibernate query language string to retrieve data from the data base and create objects. A query instance is used to bind query parameters, limits the number of results returned by the query, and finally to execute the query.
Criteria objects: Criteria objects are used to create and execute object oriented criteria queries to retrieve objects.
Reasons to choose Hibernate over JDBC
JDBC stands for Java Database Connectivity. It is a free open source application programming interface for Java that enables applications to access databases. It enables developers to create queries and update data to a relational database using the structured query language (SQL).
- Object Mapping : In JDBC, you need to write code to map the object model’s data representation to relational model and its corresponding schema. Hibernate itself maps java classes to database tables using XML or by using annotations.
- HQL : Hibernate uses HQL(Hibernate Query Language), which is similar to SQL, but Hibernate’s HQL provides full support for polymorphic queries. HQL understands object-oriented concepts like inheritance, polymorphism, and association.
- Minimize Code Changes : Hibernate minimize code changes when we add a new column to a database table.
- Reduce Repeat Code : JDBC will throw SQL exception, which is checked exception. So you will be writing “try-catch” blocks in your code. Hibernate handles this by converting all JDBC exceptions to unchecked exception. Therefore, you need not waste your time implementing try-catch blocks.
- Versioning : Database versioning is an important feature of Hibernate. Hibernate framework enables developers to define version type field in an application, which is updated when data is updated every time. The advantage is, if two different users retrieve the same data and then modify it, and one user saved their modified data to the database before the other use, the version is updated. Now when the other user tries to saves their data, it will not allow it because this data is not up to data. In JDBC, this check is performed by the developer.
Now it Is clear that Hibernate framework will definitely increase the performance of your application and help you reduce the development time for your application – and hence the cost. So by considering the above-mentioned advantages, I will recommend that everyone use Hibernate framework over JDBC.