To the Reader

In late 1995, the Java programming language burst onto the Internet scene

and gained instant celebrity status. The promise of Java technology was that

it would become the universal glue that connects users with information

wherever it comes from—web servers, databases, information providers, or

any other imaginable source. Indeed, Java is in a unique position to fulfill

this promise. It is an extremely solidly engineered language that has gained

wide acceptance. Its built-in security and safety features are reassuring both

to programmers and to the users of Java programs. Java has built-in support

for advanced programming tasks, such as network programming, database

connectivity, and concurrency.

Since 1995, eleven major revisions of the Java Development Kit have been

released. Over the course of the last 20 years, the Application Programming

Interface (API) has grown from about 200 to over 4,000 classes. The API now

spans such diverse areas as user interface construction, database management,

internationalization, security, and XML processing.

The book that you are reading right now is the first volume of the eleventh

edition of Core Java. Each edition closely followed a release of the Java Devel￾opment Kit, and each time, we rewrote the book to take advantage of the

newest Java features. This edition has been updated to reflect the features of

Java Standard Edition (SE) 9, 10, and 11.

As with the previous editions of this book, we still target serious programmers

who want to put Java to work on real projects. We think of you, our reader, as a

programmer with a solid background in a programming language other than

Java, and we assume that you don’t like books filled with toy examples (such

as toasters, zoo animals, or “nervous text”). You won’t find any of these in

our book. Our goal is to enable you to fully understand the Java language

and library, not to give you an illusion of understanding.

In this book you will find lots of sample code demonstrating almost every

language and library feature that we discuss. We keep the sample programs

purposefully simple to focus on the major points, but, for the most part, they

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aren’t fake and they don’t cut corners. They should make good starting points

for your own code.

We assume you are willing, even eager, to learn about all the advanced features that Java puts at your disposal. For example, we give you a detailed

treatment of

• Object-oriented programming

• Reflection and proxies

• Interfaces and inner classes

• Exception handling

• Generic programming

• The collections framework

• The event listener model

• Graphical user interface design

• Concurrency

With the explosive growth of the Java class library, a one-volume treatment

of all the features of Java that serious programmers need to know is no longer

possible. Hence, we decided to break up the book into two volumes. This

first volume concentrates on the fundamental concepts of the Java language,

along with the basics of user-interface programming. The second volume,

Core Java, Volume II—Advanced Features, goes further into the enterprise features

and advanced user-interface programming. It includes detailed discussions of

• The Stream API

• File processing and regular expressions

• Databases

• XML processing

• Annotations

• Internationalization

• Network programming

• Advanced GUI components

• Advanced graphics

• Native methods