RESTful 笔记
REST（Representational State Transfer）是 Roy Fielding 提出的一个描述互联系统架构风格的名词。
?
Another way to say?REST is in HTTP, any request a client can make involves a URL and an HTTP method. With REST, the URL is designed to represent a noun and the HTTP method always maps to one of several standard verbs, which will be performed against that noun.
?
?
In summary, each HTTP method will cause a well-defined action on the resource represented by the URL it operates on. The methods can be compared to SQL commands: GET is like "SELECT," DELETE is like "DELETE," POST is like "INSERT" with an auto-generated ID, and PUT is like "INSERT OR UPDATE IF EXISTS" with an ID specified.
?
REST 指的是一组架构约束条件和原则。满足这些约束条件和原则的应用程序或设计就是 RESTful。
1. stateless
有利于scalabilty，cluster
客户端可用cache提高性能
?
2. 分层
这表示组件无法了解它与之交互的中间层以外的组件，这是博士论文中提到的，不是很理解
?
3. Get/Put/Delete方法的幂等性
?
?
4. Security
与SOAP架构相比，REST架构的优点是：
SOAP接口隐藏在SOAP Envelope中了，对外暴露的是相同的URL（对于同一个web service), 不利于代理服务器根据HTTP method做安全控制， 除非解析SOAP Envelope 内容。
?
?而且SOAP 采用HTTP Post也不利于浏览器做cache
