8 Web services
Web services allow you use formats like XML or JSON to exchange information through HTTP. For example, if you want to know the weather in Shanghai tomorrow, the current share price of Apple, or product information on Amazon, you can write a piece of code to fetch that information from open platforms. In Go, this process can be comparable to calling a local function and getting its return value.
The key point is that web services are platform independent. This allows you to deploy your applications on Linux and interact with ASP.NET applications in Windows, for example, just like you wouldn't have a problem interacting with JSP on FreeBSD either.
The REST architecture and SOAP protocol are the most popular styles in which web services can be implemented these days:
- REST requests are pretty straight forward because it's based on HTTP. Every REST request is actually an HTTP request, and servers handle requests using different methods. Because many developers are familiar with HTTP already, REST should feel like it's already in their back pockets. We are going to show you how to implement REST in Go in section 8.3.
- SOAP is a standard for cross-network information transmission and remote computer function calls, launched by W3C. The problem with SOAP is that its specification is very long and complicated, and it's still getting longer. Go believes that things should be simple, so we're not going to talk about SOAP. Fortunately, Go provides support for RPC (Remote Procedure Calls) which has good performance and is easy to develop with, so we will introduce how to implement RPC in Go in section 8.4.
Go is the C language of the 21st century, aspiring to be simple yet performant. With these qualities in mind, we'll introduce you to socket programming in Go in section 8.1. Nowadays, many real-time servers use sockets to overcome the low performance of HTTP. Along with the rapid development of HTML5, websockets are now used by many web based game companies, and we will talk about this more in section 8.2.