Summary

Web services are one of the most important concepts in modern-day computing, enabling many of the rich internet applications we use today. In this chapter, we have discussed some of the criteria you would want to use while evaluating web services to use in your application, such as documentation, availability, and pricing. We briefly covered the concepts of a RESTful web service, which are stateless services that expose an interface to interact with resources through the HTTP verbs. We covered the JSON and XML formats, which are hierarchical structures used to transfer data in the body of requests, among other uses.

HTTP requests are made up of a body and a number of headers, some required, some optional, and others that contain metadata about a request and negotiate the content type. We went over the authentication methods commonly utilized by web service providers, including API keys and Open ID Connect combined with OAuth 2.0 for authorization. A REST client is a useful...