With the prominence of the Internet and the ubiquity of HTTP in today's world, web services have become the main means for web-based systems to interoperate with each other. A web service is an interface that provides access to a web-facing system for clients and other services to consume.
Simple Object Access Protocol (SOAP) used to be the de facto choice for building such services. SOAP is an XML-based communication protocol, leveraging open standards. However, in recent years Representational State Transfer (REST) has become a very popular alternative to traditional SOAP web services. So, let's take a look at the principles behind REST. This chapter will cover the following topics:
Discussions of the REST principles
How the Spring Framework can help in the building of RESTful web services
A sample RESTful web service that will provide the backdrop for the rest of this book