YOU’RE holding one part of a truly stellar phenomenon in the computing industry: the Java 2 Platform, Enterprise Edition. This book is a key piece of a visionary effort that began more than two years ago with the introduction of the J2EE platform. In that time, the J2EE engineering team has defined a new ecosystem for networked computing and taught the world a new way to develop distributed applications.

This book is about Enterprise JavaBeans 1.1 and 2.0 the second and third versions of the Enterprise JavaBeans specification. Just as the Java platform has revolutionized the way we think about software development, Enterprise JavaBeans has revolutionized the way we think about developing mission-critical enterprise software. It combines server-side components with distributed object technologies and asynchronous messaging to greatly simplify the task of application development. It automatically takes into account many of the requirements of business systems: security, resource pooling, persistence, concurrency, and transactional integrity.

JavaBeans is one of the most important developments in Java™ since its inception. It is Java's component architecture, which allows components built with Java to be used in graphical programming environments. Graphical development environments let you configure components by specifying aspects of their visual appearance (like the color or label of a button) in addition to the interactions between components (what happens when you click on a button or select a menu item). This means that someone can use a graphical tool to connect some Beans together and make an application without actually writing any Java code—in fact, without doing any programming at all.

When Java™ was first introduced in the summer of 1995, most of the IT industry focused on its graphical user interface characteristics and the competitive advantage it offered in terms of distribution and platform independence. Those were interesting times. The Applet was king, and only a few of us were attempting to use it on the server side. I reality we spent about half our time coding and the other half trying to convince management that Java was not a fad

This book has been a project spanning several years. Many have commented that the first edition was one of the best technical books they ever read. What’s made this book a reality are the many people that aided in its development. We took a big risk in developing the second edition of this book and decided to build the book on the Web.

This book gives a concise description of the Java 2 programming language, versions 1.3 and 1.4. It is a quick reference for the reader who has already learned (or is learning) Java from a standard textbook and who wants to know the language in more detail. The book presents the entire Java programming language and essential parts of the class libraries: the collection classes and the input-output classes. General rules are shown on left-hand pages mostly, and corresponding examples are shown on righthand pages only. All examples are fragments of legal Java programs.

Cryptography, the science of secret writing, is the biggest, baddest security tool in the application programmer's arsenal. Cryptography provides three services that are crucial in secure programming. These include a cryptographic cipher that protects the secrecy of your data; cryptographic certificates, which prove identity (authentication); and digital signatures, which ensure your data has not been damaged or tampered with.

This book is a tutorial on Enterprise JavaBeans (EJB). It’s about EJB concepts, methodology, and development. This book also contains a number of advanced EJB topics, giving you a practical and real-world understanding of the subject. By reading this book, you will acquire a deep understanding of EJB.

This manual assumes that you are proficient with the Java programming language. Java concepts such as classes, methods and packages are required along with a basic knowledge of object-oriented programming before continuing with this manual. See “Related Documents” later in this section of the manual for additional sources of Javarelated information.

Java didn’t come with a regex package until Java 1.4, so early programmers had to do without regular expressions. Over time, many programmers independently developed Java regex packages of varying degrees of quality, functionality, and complexity. With the early-2002 release of Java 1.4, Sun entered the fray with their java.util.regex package. In preparing this chapter, I looked at Sun’s package, and a few others (detailed starting on page 372). So which one is best? As you’ll soon see, there can be many ways to judge that.

This book describes how to develop and deploy enterprise beans for the Java™ 2 SDK, Enterprise Edition (J2EE™ SDK). The J2EE SDK is the reference implementation provided by Sun Microsystems, Inc. for the J2EE platform, a component-based architecture for creating object-oriented, enterprise-level applications. To create an application, you assemble components written in the Java programming language. The components, which are called enterprise beans, implement business tasks or business entities.

When Java™ was first introduced, most of the IT industry focused on its graphical user interface characteristics and the competitive advantage it offered in terms of distribution and platform independence. Today, the focus has broadened considerably: Java has been recognized as an excellent platform for creating enterprise solutions, specifically for developing distributed server-side applications. This shift has much to do with Java's emerging role as a universal language for producing implementation-independent abstractions for common enterprise technologies.