Book Image

Learning Network Programming with Java

Book Image

Learning Network Programming with Java

Overview of this book

Network-aware applications are becoming more prevalent and play an ever-increasing role in the world today. Connecting and using an Internet-based service is a frequent requirement for many applications. Java provides numerous classes that have evolved over the years to meet evolving network needs. These range from low-level socket and IP-based approaches to those encapsulated in software services. This book explores how Java supports networks, starting with the basics and then advancing to more complex topics. An overview of each relevant network technology is presented followed by detailed examples of how to use Java to support these technologies. We start with the basics of networking and then explore how Java supports the development of client/server and peer-to-peer applications. The NIO packages are examined as well as multitasking and how network applications can address practical issues such as security. A discussion on networking concepts will put many network issues into perspective and let you focus on the appropriate technology for the problem at hand. The examples used will provide a good starting point to develop similar capabilities for many of your network needs
Table of Contents (16 chapters)
Learning Network Programming with Java
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
Index

UDP multicasting


Multicasting is the process of sending a message to multiple clients at the same time. Each client will receive the same message. In order to participate in this process, clients need to join a multicast group. When a message is sent, its destination address indicates that it is a multicast message. The multicast groups are dynamic with clients entering and leaving the group at any time.

Multicast is the old IPv4 CLASS D space and uses addresses 224.0.0.0 through 239.255.255.255. The IPv4 Multicast Address Space Registry lists multicast address assignments and is found at http://www.iana.org/assignments/multicast-addresses/multicast-addresses.xml. The Host Extensions for IP Multicasting document is found at http://tools.ietf.org/html/rfc1112. It defines the implementation requirements to support multicasting.

The UDP multicast server

The server application is declared next. This server is a time server that will broadcast the current data and time every second. This is a good...