EJB 3 Developer Guide

Book Image

EJB 3 Developer Guide

By : Michael Sikora

Book Image

EJB 3 Developer Guide

By: Michael Sikora

Overview of this book

EJB 3 Developer Guide

EJB 3 Developer Guide

Credits

About the Author

About the Author

About the Reviewers

About the Reviewers

Preface

Free Chapter

Introduction to the EJB 3 Architecture

Introduction to the EJB 3 Architecture

Introduction to the Java EE Architecture

The EJB 3 Architecture

Getting Started

Session Beans

Stateless Session Beans

Stateful Session Beans

Local Interfaces

Entities

Introducing the EntityManager

Packaging and Deploying Entities

Field-Based Annotations

Generating Primary Keys

Overriding Metadata Defaults

Object/Relational Mapping

Object/Relational Mapping

O/R Mapping Default Behavior

O/R Mapping Overriding Defaults

O/R Mapping Additional Annotations

O/R Inheritance Mapping

The Java Persistence Query Language

The Java Persistence Query Language

Conditional Expressions

Aggregate Functions

Queries with Relationships

Collection Comparison Expressions

Constructor Expressions

Queries with Parameters

Handling Date and Time

Bulk Update and Delete

Entity Manager

Application-managed Entity Manager

Entity Manager Merge

Entity Manager Methods

Cascade Operations

Extended Persistence Context

Entity LifeCycle Callback Methods

Transactions

Container-Managed Transaction Demarcation

Examples of Transaction Attributes

Controlling Container Managed Transactions

Concurrency and Database Locking

UserTransaction Interface

Messaging

Java Message Service (JMS) API

Queue Producer and Consumer Examples

Topic Producer and Consumer Examples

Motivation for Message-Driven Beans

A Simple Message-Driven Bean Example

MDB Activation Configuration Properties

MessageDrivenContext

MDB Example Revisited

Sending Message Confirmation to a Client

MDBs and Transactions

EJB Timer Service

EJB Timer Service

Timer Service Examples

A Timer Interface Example

Timers and Transactions

Interceptors

Interceptor Methods

Interceptor Classes

Default Interceptors

Interceptor Communication

Implementing EJB 3 Web Services

Implementing EJB 3 Web Services

Overview of Web Service Concepts

Creating a Java Application Web Service

Overriding JAX-WS Annotation Defaults

Deploying an EJB Session Bean as a Web Service

EJB 3 Security

Java EE Container Security

EJB Authorization

Java EE Web Container Security

Annotations and Their Corresponding Packages

Annotations and Their Corresponding Packages

Customer Reviews

5 star

0

4 star

0

3 star

0

2 star

0

1 star

0

Chapter 5. The Java Persistence Query Language

EJB 3 provides the Java Persistence Query Language (JPQL). In this chapter we will cover:

Projections
GROUP BY and HAVING clauses
Joins
Subqueries
Dynamic Queries
Functions
Queries with parameters
Handling Date and Time
Bulk update and delete operations
Native SQL

Introduction

A rather limited query language, EJB QL, was provided in EJB 2.0 and 2.1. JPQL enhances EJB QL by providing the following features: JOINs, GROUP BY, HAVING, projection, subqueries, dynamic queries, bulk update and delete. We shall see examples of all these features in this chapter.

JPQL is similar to the SQL language for querying relational databases. However, JPQL queries are expressed in Java objects rather than tables and columns. As SQL dialects differ between relational database vendors, JPQL has an added advantage of portability across databases. The entity manager uses the JDBC configuration specified in the persistence.xml file to convert the JPQL query to native SQL.

There...