是什么原因导致甚至没有看到一些“有用的”和公开的基于websocket的服务？

Question

What's the reason for not seeing even a handful of "useful" and publicly available websocket based services out there?

RESTful services are plenty like the one below which is weather forecast related.

http://api.openweathermap.org/data/2.5/forecast?q=chicago,us&mode=json

However, why aren't there services like

ws://api.openweathermap.org/...

with some documentation about what messages a websocket client can expect to send and receive bi-directionally over a single connection?

Answer 1

What's the reason for not seeing even a handful of "useful" and publicly available websocket based services out there?

Maybe because websockets were not created for that? They came from the HTML5 initiative and were created to replace Ajax interaction between a browser and a web site for real time web applications. No more polling, long-polling, streaming, flash sockets, or any other HTTP hack to make a server push data to the browser. Webocket is the real thing.

Most web services now follow a request/reply pattern while the websocket is still a maturing technology. Give it time and services will appear, services that actually need the capabilities of websockets and not use them just because "there is a new kid in town".

As a final note, here is something for websockets emerging from Microsoft.