Mastering Hibernate

Ramin Rad

• Publisher: Packt Publishing
• Year: 2016
• eBook ISBN: 9781782175339
• Edition: 1
• Topic: Computer Science
• Subtopic: Programming in Java
• Index: Computer Science

Learn how to correctly utilize the most popular Object-Relational Mapping tool for your Enterprise application

About This Book

• Understand the internals of Hibernate and its architecture, and how it manages Entities, Events, Versioning, Filters, and Cache
• Observe how Hibernate bridges the gap between object-oriented concepts and relational models
• Discover how Hibernate can address architectural concerns such as Transaction, Database Multi-tenancy, Clustering, and Database Shards

Who This Book Is For

Mastering Hibernate is intended for those who are already using or considering using Hibernate as the solution to address the problem of Object Relational Mapping. If you are already using Hibernate, this book will help you understand the internals and become a power user of Hibernate.

What You Will Learn

• Understand the internals of a Hibernate session and how Entities are managed
• Declare better mapping between entity classes and database tables
• Manage entity associations and collections
• Fetch data not just by entity ID, but also using HQL, Criteria Objects, Filters, and Native SQL
• Observe the first and second level caches and find out how to manage them
• Collect statistics and metrics data for further observation
• Make your application work with multi-tenant databases

In Detail

Hibernate has been so successful since its inception that it even influenced the Java Enterprise Edition specification in that the Java Persistence API was dramatically changed to do it the Hibernate way. Hibernate is the tool that solves the complex problem of Object Relational Mapping. It can be used in both Java Enterprise applications as well as.Net applications. Additionally, it can be used for both SQL and NoSQL data stores.

Some developers learn the basics of Hibernate and hit the ground quickly. But when demands go beyond the basics, they take a reactive approach instead of learning the fundamentals and core concepts. However, the secret to success for any good developer is knowing and understanding the tools at your disposal. It's time to learn about your tool to use it better

This book first explores the internals of Hibernate by discussing what occurs inside a Hibernate session and how Entities are managed. Then, we cover core topics such as mapping, querying, caching, and we demonstrate how to use a wide range of very useful annotations.

Additionally, you will learn how to create event listeners or interceptors utilizing the improved architecture in the latest version of Hibernate.

Style and approach

This book takes a close look at the core topics, and helps you understand the complex topics by showing you examples and giving you in-depth discussions.

Mastering Hibernate

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Table of Contents

Mastering Hibernate

Credits

About the Author

About the Reviewers

www.PacktPub.com

eBooks, discount offers, and more

Why subscribe?

Preface

What this book covers

What you need for this book

Who this book is for

Conventions

Reader feedback

Customer support

Downloading the example code

Errata

Piracy

Questions

1. Entity and Session

Why this book?

Quick Hibernate

Working with a session

Session internals

Contextual session

Session per request

Session per conversation

Session per operation

Stateless session

Entity

Entity lifecycle

Types of entities

Identity crisis

Beyond JPA

Proxy objects

Batch processing

Manual batch management

Setting batch size

Using stateless session

Summary

2. Advanced Mapping

Mapping concepts

Instances and rows

Annotation versus XML

Owning entity

Value mapping

JPA ID generation

Hibernate ID generation

Composite ID

Association cardinality

One-to-one associations

One-to-many associations

Many-to-one associations

Many-to-many associations

Self-referencing tables

Cascade operations

Inheritance

Single table strategy

Table per class strategy

Joined strategy

Enumeration and custom data type

Enumerated type

Custom data type mapping

Summary

3. Working with Annotations

Mapping and association

@Any and @ManyToAny

@MapsId

@Fetch

@OrderBy

@ElementCollection and @CollectionTable

Behavior

@Cache

@Access

@Cascade

@CreationTimestamp and @UpdateTimestamp

@Filter and @FilterDef

@Immutable

@Loader

@NotFound

@SortComparator and @SortNatural

SQL/DDL modifier

@Check

@ColumnDefault

@ColumnTransformer

@DynamicInsert and @DynamicUpdate

@Formula

@SelectBeforeUpdate

@SQLDelete and @Where

@SQLInsert and @SQLUpdate

@SubSelect and @Synchronize

@WhereJoinTable

@NaturalId

Summary

4. Advanced Fetching

Fetching strategy

The JOIN fetch mode

The SELECT fetch mode

The SUBSELECT fetch mode

Batch fetching

Hibernate Query Language

Fetch queries

Delete and update

Join

Native SQL

Scalar query

Entity query

Criteria objects

Filters

Pagination

Summary

5. Hibernate Cache

Cache structure

Cache scope

First-level cache

Second-level cache

Cache provider interface

Ehcache implementation

Cache configuration

Query cache

Caching benefits and pitfalls

Caching strategies

Read only

Non-strict read write

Read-write

Transactional

Object identity

Managing the cache

Remove cached entities

Cache modes

Cache metrics

Summary

6. Events, Interceptors, and Envers

Services

Service loader

Service registry

The OSGi model

Events

Event listener

Registering listeners

Interceptors

Database trigger

Event or interceptor

Envers

Configuration

Strategy

Fetching revisions

Summary

7. Metrics and Statistics

Statistical data types

Session

Entity

Collection

Query

Cache

Statistics via JMX

Introduction to JMX

Using JMX with Hibernate

Summary

8. Addressing Architecture

Architecture matters

Transaction management

Local transactions

The Java Transaction API

Compensating transactions

Concurrency

Isolation levels

Locking

User lock

Scalability

Clustering

Database shards

Configuration

Sharded session factory

Shard strategy

Shard ID generation

Performance

Lazy loading

Fetch mode

Batch processing

Caching

Stateless session

Legacy application

Reverse engineering

Modernization

The Cloud strategy

Licensing

Multi-tenancy

Summary

9. EJB and Spring Context

Deployment

Configuration

Resource

Transaction

Hibernate libraries

EJB

Persistence unit

Server resources

Entity manager

Transaction

Hibernate session

Spring

Configuration

Transaction management

Data source

Session factory

Summary

Index

Mastering Hibernate

Copyright © 2016 Packt Publishing

All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, without the prior written permission of the publisher, except in the case of brief quotations embedded in critical articles or reviews.

Every effort has been made in the preparation of this book to ensure the accuracy of the information presented. However, the information contained in this book is sold without warranty, either express or implied. Neither the author, nor Packt Publishing, and its dealers and distributors will be held liable for any damages caused or alleged to be caused directly or indirectly by this book.

Packt Publishing has endeavored to provide trademark information about all of the companies and products mentioned in this book by the appropriate use of capitals. However, Packt Publishing cannot guarantee the accuracy of this information.

First published: May 2016

Production reference: 1100516

Published by Packt Publishing Ltd.

Livery Place

35 Livery Street

Birmingham B3 2PB, UK.

ISBN 978-1-78217-533-9

www.packtpub.com

Credits

Author

Ramin Rad

Reviewers

Luca Masini

Sherwin John Calleja-Tragura

Aurélie Vache

Commissioning Editor

Neil Alexander

Acquisition Editor

Reshma Raman

Content Development Editor

Zeeyan Pinheiro

Technical Editor

Pranjali Mistry

Copy Editor

Pranjali Chury

Project Coordinator

Francina Pinto

Proofreader

Safis Editing

Indexer

Rekha Nair

Production Coordinator

Manu Joseph

Cover Work

Manu Joseph

About the Author

Ramin Rad has been working as a software professional for the last 20 years, living in Washington DC area. He studied mathematics and computer science in the academic world, and he cares deeply for the art of software development.

He is also a musician, a guitarist, who performs regularly in the DC area and beyond. His artistic side is significant because he believes that writing software is more art than science, following the philosophy of the likes of Donald Knuth, who wrote the Art of Computer Programming series.

Currently, he is a director and a solution architect at a large international software product and services company, focusing on enterprise, mobile, and cloud-based solutions.

I would like to thank three people who have made a significant impact on my professional life and career: my friend, Terry Rice, who always encouraged me to think scientifically and redirect my focus toward software architecture; my idol, Dr. Paul Eggert, who for me is a true computer scientist and with whom I had the pleasure of working; and finally my mentor, Jon King, who has guided me the most throughout my career and personal life.

Finally, I dedicate this book to my beautiful children, Mina and Cyrus. I hope when you grow up, you too love and learn all about life, nature, and science, and share what you learn with the world.

About the Reviewers

Luca Masini is a senior software engineer and architect. He started off as a game developer for Commodore 64 (Football Manager) and Commodore Amiga (Ken il guerriero). He soon converted to object oriented programming, and for that, from its beginning in 1995, he was attracted by the Java language.

Following his passion, he worked as a consultant for major Italian banks, developing and integrating the main software projects for which he has often taken technical leadership. He encouraged the adoption Java Enterprise in environments where COBOL was the flagship platform, converting them from mainframe centric to distributed.

He then shifted his focus toward open source, starting from Linux and then m...

Table of contents

• Mastering Hibernate