Computacion Distribuida

Preface
Java™'s growth over the last five years has been nothing short of phenomenal. Given Java's rapid rise to prominence and the general interest in networking, it's a little surprising that network programming in Java is still so mysterious to so many. This doesn't have to be. In fact, writing network programs in Java is quite simple, as this book will show. Readers with previous experiencein network programming in a Unix, Windows, or Macintosh environment should be pleasantly surprised at how much easier it is to write equivalent programs in Java. That's because the Java core API includes well-designed interfaces to most network features. Indeed, there is very little application layer network software you can write in C or C++ that you can't write more easily in Java. Java NetworkProgramming endeavors to show you how to take advantage of Java's network class library to quickly and easily write programs that accomplish many common networking tasks. These include:
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Browsing pages on the Web Parsing and rendering HTML Sending email with SMTP Receiving email with POP and IMAP Writing multithreaded servers Installing new protocol and contenthandlers into browsers Encrypting communications for confidentiality, authentication, and guaranteed message integrity Designing GUI clients for network services Posting data to CGI programs Looking up hosts using DNS Downloading files with anonymous FTP Connecting sockets for low-level network communication Distributing applications across multiple systems with Remote Method Invocation

Java is thefirst language to provide such a powerful cross-platform network library that handles all these diverse tasks. Java Network Programming exposes the power and sophistication of this library. This book's goal is to enable you to start using Java as a platform for serious network programming. To do so, this book provides a general background in network fundamentals as well as detailed discussions ofJava's facilities for writing network programs. You'll learn how to write Java applets and

applications that share data across the Internet for games, collaboration, software updates, file transfer and more. You'll also get a behind-the-scenes look at HTTP, CGI, TCP/IP, and the other protocols that support the Internet and the Web. When you finish this book, you'll have the knowledge and thetools to create the next generation of software that takes full advantage of the Internet.

About the Second Edition
In the first chapter of the first edition of this book, I wrote extensively about the sort of dynamic, distributed network applications I thought Java would make possible. One of the most exciting parts of writing this second edition was seeing that virtually all of the applicationsI had postulated have indeed come to pass. Programmers are using Java to query database servers, monitor web pages, control telescopes, manage multiplayer games, and more, all by using Java's ability to access the Internet. Java in general, and network programming in Java in particular, has moved well beyond the hype stage and into the realm of real, working applications. Not all network softwareis written in Java yet, but it's not for a lack of trying. Efforts are well under way to subvert the existing infrastructure of C-based network clients and servers with pure Java replacements. It's unlikely that Java will replace C for all network programming in the near future. However, the mere fact that many people are willing to use web browsers, web servers, and more written in Java showsjust how far we've come since 1996. This book has come a long way too. The second edition has been rewritten almost from scratch. There are five completely new chapters, some of which reflect new APIs and abilities of Java introduced since the first edition was published (Chapter 8, Chapter 12, and Chapter 19 ), and some of which reflect my greater experience in teaching this material and noticing...