SOAP

简单对象访问协议(SOAP)是一种标准的XML语言，定义了消息体系结构和消息格式。Web服务使用它。它包含操作的描述。

WSDL是一种基于xml的语言，用于描述Web服务以及如何访问它们。它将运行在SMTP, HTTP, FTP等。它需要中间件支持和定义良好的机制来定义WSDL+XSD和WS-Policy等服务。 SOAP将返回基于XML的数据

REST

具象状态传输(RESTful) web服务。它们是第二代Web服务。

基于rest的web服务通过HTTP而不是基于soap的服务进行通信，并且不需要XML消息或WSDL服务api定义。对于REST中间件不需要，只需要HTTP支持。它是一个WADL标准，REST可以返回XML、纯文本、JSON、HTML等。

REST是一种体系结构。 REST将给出人类可读的结果。 REST是非状态的。 REST服务很容易被缓存。

SOAP是一种协议。它可以运行在JMS、FTP和HTTP之上。

SOAP web服务总是执行POST操作，而使用REST，您可以选择特定的HTTP方法，如GET、POST、PUT和DELETE。

例如:要使用SOAP获取一个项目，您应该创建一个请求XML，但是在REST的情况下，您可以在URL本身中指定项目id。

REST stands for representational state transfer whereas SOAP stands for Simple Object Access Protocol. SOAP defines its own security where as REST inherits security from the underlying transport. SOAP does not support error handling, but REST has built-in error handling. REST is lightweight and does not require XML parsing. REST can be consumed by any client, even a web browser with Ajax and JavaScript. REST consumes less bandwidth, it does not require a SOAP header for every message. REST is useful over any protocol which provide a URI. Ignore point 5 for REST as mentioned below in the picture.

REST和SOAP的区别:

REST vs. SOAP Web Services I am seeing a lot of new web services are implemented using a REST style architecture these days rather than a SOAP one. Lets step back a second and explain what REST is. What is a REST web service? The acronym REST stands for representational state transfer, and this basically means that each unique URL is a representation of some object. You can get the contents of that object using an HTTP GET, to delete it, you then might use a POST, PUT, or DELETE to modify the object (in practice most of the services use a POST for this). Who's using REST? All of Yahoo's web services use REST, including Flickr and Delicious. APIs use it, pubsub, bloglines, Technorati, and both eBay, and Amazon have web services for both REST and SOAP. Who's using SOAP? Google seams to be consistent in implementing their web services to use SOAP, with the exception of Blogger, which uses XML-RPC. You will find SOAP web services in lots of enterprise software as well. REST vs. SOAP As you may have noticed the companies I mentioned that are using REST APIs haven't been around for very long, and their APIs came out this year mostly. So REST is definitely the trendy way to create a web service, if creating web services could ever be trendy (lets face it you use soap to wash, and you rest when your tired). The main advantages of REST web services are: Lightweight - not a lot of extra XML markup Human Readable Results Easy to build - no toolkits required. SOAP also has some advantages: Easy to consume - sometimes Rigid - type checking, adheres to a contract Development tools For consuming web services, its sometimes a toss up between which is easier. For instance Google's AdWords web service is really hard to consume (in ColdFusion anyway), it uses SOAP headers, and a number of other things that make it kind of difficult. On the converse, Amazon's REST web service can sometimes be tricky to parse because it can be highly nested, and the result schema can vary quite a bit based on what you search for. Whichever architecture you choose make sure its easy for developers to access it, and well documented.

Freitag, P.(2005)。“REST vs SOAP Web服务”。检索自http://www.petefreitag.com/item/431.cfm, 2010年6月13日