Chapter 1 Introduction to EJB 3—A general overview of the Java EE architecture including EJB container services, the JPA persistence engine, and initial installation of the GlassFish application server.

Chapter 2 Session Beans—Creation of a session bean and its client and examples of running it from the application client container. Exploring the program directory structure. Packaging and deploying a session bean. A look at the stateless and stateful session beans lifecycle.

Chapter 3 Entities—Exploring EJB 3 entities. How to package and deploy entities and map an entity to a database table. Metadata defaults and how to override them. Generating primary keys.

Chapter 4 Object/Relational Mapping—One-to-one, one-to-many and many-to-many associations. Default object/relational mapping values and how to override them. Object/relational inheritance mapping and additional annotations.

Chapter 5 JPQL (Java Persistence Query Language)—Looking at different groups of queries including aggregate functions, queries with relationships, subqueries, queries with parameters and named queries. JPQL joins and functions are also explained.

Chapter 6 Entity Manager—Looks in detail at the entity manager. Covers both the EJB 3 container-managed and application-managed entity managers.

Chapter 7 Transactions—ACID properties and isolation levels. Container-managed transactions. Bean-managed transactions.

Chapter 8 Messaging—Looks at the JMS (Java Messaging Service) API. Examples of queue producer and queue consumers. Topic producer and consumers. Message driven beans: their activation configuration properties, lifecycles and transactions.

Chapter 9 EJB Timer Service—Examples of single and interval events. Timer interface methods. Timers and transactions.

Chapter 10 Interceptors—Covers interceptor methods, classes and interceptor communication as well as default interceptors.

Chapter 11 Implementing EJB 3 Web Services—An overview of web service concepts and the web service definition language (WSDL). Creating and deploying a Java application as a web service. Creating and deploying an EJB session bean as a web service. Creating a web service client.

Chapter 12 EJB 3 Security—A look at security, GlassFish authentication, declarative and programmatic EJB authorization and Web Tier authentication and authorization.

The Appendix shows EJB 3 annotations described in this book with their corresponding packages.

First you must have version 5 or higher of the Java Development Kit (JDK). This can be downloaded from http://java.sun.com/javase/downloads/index.jsp.

You also need a version of Ant equal to or higher than 1.6.5. Ant is a tool for building Java programs, similar in concept to the Unix Make tool, except that it is platform independent. Ant is part of Apache’s Jakarta project. If you are unfamiliar with Ant you should look at the Ant web site (http://ant.apache.org/). If you do not have Ant there is no need to download it as the GlassFish application server includes a copy of Ant.

Finally you need a version of GlassFish equal to or higher than V2b41d. This can be downloaded from https://glassfish.dev.java.net//.

Instructions on setting up environment variables and installing GlassFish are given in the "Getting Started" section in Chapter 1.

Previous experience of working with Java is essential and knowledge of relational databases is desirable.

This book is primarily aimed at professional developers who already have a working knowledge of Java. Enterprise architects and designers with a background in Java would also find this book of use.

As this book is an introduction to EJB 3, it is aimed at those who are new to EJB 3. However, as the new version of EJB is so radically different from the previous version (EJB 2.x), the book would also be suitable and of interest to those who have had experience working with EJB 2.x. The text makes it clear where the differences between the versions of EJB lie, although it is not explored in detail.

This book has been written for developers new to EJB 3 who want to use the technology. Such readers usually want to see examples and program code. In this book we work through one example after another and we show lots of program code. If you are new to a technology and have looked at your first HelloWorld example, the next thing you want to do is to code and run the program yourself. In the case of EJBs this also means packaging and deploying the EJB to a container. Although we promise no HelloWorld examples in this book, we look at packaging and deployment straight after coding our first EJB, rather than ignoring these topics or leaving them to the end of the book.

All the source code together with packaging and deployment scripts is available from the book's web site.

This book is not a reference book, so we don't attempt to cover all EJB 3 features. We've kept this book concise to help you quickly get up and running with EJB 3.

Although an EJB will run in any EJB container, the deployment process is container-dependent. This means that we need to pick a specific container for our examples. Sun's open-source, free GlassFish container was chosen primarily because this was the Java EE reference container implementation and also because GlassFish has Toplink embedded. Toplink in turn is the reference JPA persistence engine.

We also chose not to use an IDE (Integrated Development Environment) partly because they are all quite different. A book based on IDE A would be of little use to a reader using IDE B. As IDEs are screen-based navigational tools, any resulting book would contain a large number of screenshots and would be at least double in length. More importantly is the author's view that an IDE is not an ideal learning tool. Apart from having to learn to navigate through a large number of screens, often an IDE will hide the underlying EJB technology. Of course once you have learnt EJB an IDE will make you much more productive in your work.

Instead we use the Ant build tool for compiling, packaging, deploying, and running our EJBs.

In this book, you will find a number of styles of text that distinguish between different kinds of information. Here are some examples of these styles, and an explanation of their meaning.

Code words in text are shown as follows: "We name our interface TimeService.java, which contains a single method definition getTime() ."

A block of code will be set as follows:

@Stateless
public class TimeServiceBean implements TimeService {
public String getTime() {
Formatter fmt = new Formatter();
Calendar cal = Calendar.getInstance();
fmt.format("%tr", cal);
return fmt.toString();
}
}

When we wish to draw your attention to a particular part of a code block, the relevant lines or items will be made bold:

@Stateless
public class TimeServiceBean implements TimeService {
private @EJB NiceDayService niceDay;
public String getTime() {
Formatter fmt = new Formatter();
Calendar cal = Calendar.getInstance();
fmt.format("%tr", cal);
return fmt.toString() +
niceDay.getMessage();
}
}

Any command-line input and output is written as follows:

C:\EJB3Chapter02\glassfish\lab1\build>jar -tvf TimeService.jar

New terms and important words are introduced in a bold-type font. Words that you see on the screen, in menus or dialog boxes for example, appear in our text like this: " Under the Web Services heading in the Common Tasks pane on the left of the screen, click on Arithmetic ."

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