Book Image

Learning Internet of Things

By : Peter Waher
Book Image

Learning Internet of Things

By: Peter Waher

Overview of this book

<p>This book starts by exploring the popular HTTP, UPnP, CoAP, MQTT, and XMPP protocols. You will learn how protocols and patterns can put limitations on network topology and how they affect the direction of communication and the use of firewalls. Thing registries and delegation of trust are introduced as important tools to secure the life cycle of Things on the Internet. Once the fundamentals have been mastered, your focus will move to the Internet of Things architecture. A secure architecture is proposed that will take full advantage of the power of Internet of Things and at the same time protect end user integrity and private personal data without losing flexibility and interoperability.</p> <p>This book provides you with a practical overview of the existing protocols, communication patterns, architectures, and security issues important to Internet of Things.</p>
Table of Contents (16 chapters)
Learning Internet of Things
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Implementing the Still Image service


As we have seen, UPnP services use SOAP to call actions published by the service. But instead of using WSDL to describe the service method calls, a Service Control Protocol Description (SCPD) document is used. Apart from being much more restrictive when it comes to defining web methods, it also has an added feature that is not supported by normal web services: handling of GENA-type events and event subscriptions. When we implement a UPnP web service, we will do so by inheriting the UPnPWebService class defined in the Clayster.Library.Internet.UPnP namespace. This class in turn is inherited from the normal HttpServerWebService class but adds event handling and subscription capabilities to the web service:

public class DigitalSecurityCameraStillImage : UPnPWebService
  {
    public DigitalSecurityCameraStillImage() : base("/StillImage")
  {

Initializing evented state variables

Still in the constructor of the web service, there are no subscribers to the state...