Hibernate Training

Hibernate is the most popular object-relational mapping framework for Java environments. Object relational mapping in large enterprise applications is difficult. In this class, students learn object-relational mapping concepts and the various issues and options available in Java to address object persistence. With these fundamentals, the course then explores the basics of Hibernate object persistence and configuration. It also digs into the details of Hibernate mapping, queries, transactions, and concurrency.

This course is loaded with lots of hands on examples and deals with maintenance and performance issues. After taking this class, developers will be able to build faster, more flexible and easier to maintain application persistence layers with the Hibernate framework.

Hibernate Training Course Content Objective

• Understand the challenges of mapping objects to relational databases
• Learn the architecture of Hibernate
• Know how to setup and configure Hibernate for a Java Project
• Learn to map Java classes and object associations to relational database tables with Hibernate mapping files
• Study Hibernate’s strategies for mapping Java inheritance trees to relational database tables
• Learn the Hibernate Query Language and Criteria for retrieving Java objects
• Explore Hibernate’s Caching Architecture

Architecture

To learn more about hibernate we need to understand its architecture which comprises of :

• A Java application code consists of all the classes, variables and objects that define the business logic of the application. These classes communicate with the Hibernate.
• Then comes, the Hibernate and its core principles, using which we could persist ( store or save and retrieve ) the objects of our business layer classes by communicating with the database server layer.
• It uses the Java core API, Java Database Connectivity(JDBC), Java Transaction API(JTA), Java Naming and Directory Interface(JNDI) to communicate with the database in order to persist the state of an object by performing read, create, update, delete(CRUD) operations.

It is basically used to communicate with the database. Here we just create some entities, which is nothing but a java class that will create a database table for us in the database.

Framework

• Used best JDBC concepts such as:
• Rowset instead of ResultSet
• DataSource (connection pooling) instead of DriverManager
• Batch operations instead of individual operation
• PreparedStatement instead of Statement
• Project development cost is reduced to a large factor.
• No memory leaks
• Managing associations such as one-to-many, etc are simple and easy as compared to working with collection properties like java.util.Set, List, Map.
• Being an ORM framework, the Hibernate will get all its advantages:
• Supports Second level cache
• The object becomes a record and vice versa.
• Additionally supports Object Query Language (HQL)
• Supports multiple primary key generators

Features of Hibernate 

• It supports JMX and JCA.
• It provides a feature of J2EE integration.
• At system initialization time it generates SQL.
• Optionally provide internal connection pooling and prepared statement caching.
• It supports optimistic locking with versioning.
• It provides outer join fetching.
• It introduces Lazy initialization.
• It provides session-level cache and optional second-level cache.
• It provides Dual-layer Cache Architecture.
• Automatic generation of the primary key.
• It supports the tough concept of composite keys.
• It supports Detached object concept.
• It introduces automatic Dirty Checking concept.
• It provides transparent persistence without byte code processing.
• It provides Object/Relational mappings. Here are different O/R mapping strategies as multiple-objects to single-row mapping,
• Polymorphic associations, bi-directional association, association filtering. It also provides XML mapping documents.
• It provides different object-oriented query languages.
• Minimal object-oriented Hibernate query language(HQL), native SQL queries
• High object-oriented concept of criteria.

Why we use Hibernate?

• Transaction management
• Associations
• Inheritance
• Hibernate caching
• Versioning
• Audit functionality
• JPA annotation support
• Connection Pooling
• Avoiding try-catch blocks
• Avoid lazy loading
• Reduces repeat code

Advantages

Covering the topic let us start with the advantages of hibernate which are as follows :

• ORM – maintenance is easy and cost-effective.
• Transparent Persistence
• Database independent
• HQL – HQL’s advanced features like pagination and dynamic profiling are not present in SQL. So we can use it in hibernate.
• Dual-layer Caching
• Version Property
• Open Source and free software
• Scalability is easy
• Lazy-Loading – The lazy-loading concept fetches only the necessary object that is required for the execution of an application.
• Easy to Learn
• Also supports collections like List, Set, Map.
• capability to generate primary keys
• Hibernate provided Dialect classes
• It supports relationships like One-To-Many, One-To-One, Many-To-Many-to-Many, Many-To-One