我建议您先使用REST——如果您正在使用Java，请查看JAX-RS和Jersey实现。REST更简单，易于在多种语言中进行互操作。

正如其他人在这篇文章中所说，SOAP的问题在于当其他WS-*规范加入时它的复杂性，如果您误入WSDL、xsd、SOAP、WS- addressing等的错误部分，就会出现无数的互操作问题。

判断REST和SOAP之争的最好方法是看看互联网——几乎所有网络领域的大玩家，谷歌、amazon、ebay、twitter等——都倾向于使用并偏爱RESTful api而不是SOAP api。

使用REST的另一个很好的方法是，你可以在web应用程序和REST前端之间重用大量的代码和基础设施。例如，使用JAX-RS和隐式视图等框架，将资源的HTML、XML和JSON呈现出来通常是非常容易的，而且使用web浏览器也很容易处理RESTful资源

回答2012年刷新的问题(通过第二个赏金)，并回顾今天的结果(其他答案)。

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SOAP的利弊

关于SOAP 1.2，与“REST”相比的优点和缺点…从2007年开始 你可以用WSDL描述REST Web服务， 并使用SOAP协议…也就是说，如果您再努力一点，web服务协议栈的所有W3C标准都可以是REST!

这是一个很好的起点，因为我们可以想象一个场景，在这个场景中，所有的哲学和方法论讨论都暂时被避免了。我们可以在技术上比较类似服务中的“SOAP-REST”和“非SOAP-REST”，

SOAP-REST (="REST-SOAP"): as showed by L.Mandel, WSDL2 can describe a REST webservice, and, if we suppose that exemplified XML can be enveloped in SOAP, all the implementation will be "SOAP-REST". NON-SOAP-REST: any REST web service that can not be SOAP... That is, "90%" of the well-knowed REST examples. Some not use XML (ex. typical AJAX RESTs use JSON instead), some use another XML strucutures, without the SOAP headers or rules. PS: to avoid informality, we can suppose REST level 2 in the comparisons.

当然，为了从概念上进行比较，可以将“NON-REST-SOAP”与“NON-SOAP-REST”作为不同的建模方法进行比较。那么，完成这个web服务分类:

NON-REST-SOAP:任何不能是REST的SOAP web服务…也就是说，“90%”的广为人知的SOAP示例。 NON-REST-NEITHER-SOAP:是的，“web服务建模”的世界包括其他东西(例如XML-RPC)。

REST条件下的SOAP

比较可比较的事物:皂歇和非皂歇。

PROS

解释一些术语，

Contractual stability: for all kinds of contracts (as "written agreements"), By the use of standars: all levels of the W3C stack are mutually compliant. REST, by other hand, is not a W3C or ISO standard, and have no normatized details about service's peripherals. So, as I, @DaveWoldrich(20 votes), @cynicalman(5), @Exitos(0) said before, in a context where are NEED FOR STANDARDS, you need SOAP. By the use of best practices: the "verbose aspect" of the W3C stack implementations, translates relevant human/legal/juridic agreements. Robustness: the safety of SOAP structure and headers. With metada communication (with the full expressiveness of XML) and verification you have an "insurance policy" against any changes or noise. SOAP have "transactional reliability (...) deal with communication failures. SOAP has more controls around retry logic and thus can provide more end-to-end reliability and service guarantees", E. Terman.

按受欢迎程度排序，

更好的工具(~70票):从2007年到2012年，SOAP目前拥有更好的工具的优势，因为它是一个定义良好且被广泛接受的标准。参见@MarkCidade(27票)，@DaveWoldrich(20票)，@JoshM(13票)，@TravisHeseman(9票)。 标准遵从性(25票):正如我，@DaveWoldrich(20票)，@愤世嫉俗的人(5票)，@Exitos(0票)之前所说，在需要标准的上下文中，您需要SOAP。 健壮性:SOAP头的保险，@JohnSaunders(8票)。

CONS

SOAP strucuture is more complex (more than 300 votes): all answers here, and sources about "SOAP vs REST", manifest some degree of dislike with SOAP's redundancy and complexity. This is a natural consequence of the requirements for formal verification (see below), and for robustness (see above). "REST NON-SOAP" (and XML-RPC, the SOAP originator) can be more simple and informal. The "only XML" restriction is a performance obstacle when using tiny services (~50 votes): see json.org/xml and this question, or this other one. This point is showed by @toluju(41), and others. PS: as JSON is not a IETF standard, but we can consider a de facto standard for web software community.

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使用SOAP对服务建模

现在，我们可以添加SOAP- non - rest与非SOAP- rest比较，并解释什么时候使用SOAP更好:

Need for standards and stable contracts (see "PROS" section). PS: see a typical "B2B need for standards" described by @saille. Need for tools (see "PROS" section). PS: standards, and the existence of formal verifications (see bellow), are important issues for the tools automation. Parallel heavy processing (see "Context/Foundations" section below): with bigger and/or slower processes, no matter with a bit more complexity of SOAP, reliability and stability are the best investments. Need more security: when more than HTTPS is required, and you really need additional features for protection, SOAP is a better choice (see @Bell, 32 votes). "Sending the message along a path more complicated than request/response or over a transport that does not involve HTTP", S. Seely. XML is a core issue, offering standards for XML Encryption, XML Signature, and XML Canonicalization, and, only with SOAP you can to embed these mechanisms into a message by a well-accepted standard as WS-Security. Need more flexibility (less restrictions): SOAP not need exact correspondence with an URI; not nedd restrict to HTTP; not need to restrict to 4 verbs. As @TravisHeseman (9 votes) says, if you wanted something "flexible for an arbitrary number of client technologies and uses", use SOAP.PS: remember that XML is more universal/expressive than JSON (et al). Need for formal verifications: important to understand that W3C stack uses formal methods, and REST is more informal. Your WSDL (a formal language) service description is a formal specification of your web services interfaces, and SOAP is a robust protocol that accept all possible WSDL prescriptions.

上下文

历史

要判断趋势，必须有历史的眼光。对于这个问题，10年或15年的展望……

在W3C标准化之前，有一些混乱。很难用不同的框架实现可互操作的服务，而在公司之间实现一些可互操作的东西则更加困难、昂贵和耗时。 W3C堆栈标准一直是复杂web服务集互操作的明灯。

对于日常的任务，比如实现AJAX, SOAP很繁重……因此，需要简单的方法，需要选择一个新的理论框架…而大的“网络软件玩家”，如谷歌、亚马逊、雅虎等，选出了最佳的替代方案，那就是REST方法。在这种情况下，REST概念作为一个“竞争性框架”出现了，并且，今天(2012年)，这个替代方案已经成为程序员的事实上的标准。

基金会

在并行计算环境下，web服务提供并行子任务;和协议，如SOAP，确保良好的同步和通信。不是“任何任务”:web服务可以被分类为 粗粒度和令人尴尬的并行。

随着任务变得越来越大，“复杂性争论”变得不那么重要，而与通信的稳健性和合同的稳固性更加相关。

REST是一个体系结构，SOAP是一个协议。

这是第一个问题。

您可以在REST应用程序中发送SOAP信封。

SOAP本身实际上是相当基本和简单的，它之上的WSS-*标准使它非常复杂。

如果您的消费者是其他应用程序和其他服务器，那么目前对SOAP协议有很多支持，在现代ide中移动数据的基本操作基本上就是单击鼠标。

如果您的消费者更有可能是ria或Ajax客户端，那么您可能希望使用比SOAP更简单、更适合客户端的东西(特别是JSON)。

通过HTTP发送的JSON包不一定是REST体系结构，它只是发送到url的消息。所有这些都是完全可行的，但是REST习惯用法有一些关键组件。然而，这两者很容易混淆。但是，仅仅因为您谈论的是HTTP请求，并不一定意味着您拥有REST体系结构。您可以有一个完全没有HTTP的REST应用程序(注意，这种情况很少见)。

因此，如果您的服务器和消费者对SOAP“满意”，SOAP和WSS堆栈就可以很好地为您服务。如果你在做一些特别的事情，想要更好地与web浏览器交互，那么一些轻量级的HTTP协议也可以很好地工作。

一个老问题，但今天仍然有意义....因为许多企业领域的开发人员仍在使用它。

我的工作包括设计和开发IoT(物联网)解决方案。其中包括为与云通信的小型嵌入式设备开发代码。

很明显，REST现在已经被广泛接受和有用，而且几乎是web的事实上的标准，甚至微软在整个Azure中都包含了REST支持。如果我需要依赖SOAP，我就不能做我需要做的事情，因为对于小型嵌入式设备来说，它太大、太笨重、太烦人了。

REST简单、干净、小巧。使其成为小型嵌入式设备的理想选择。当我与一个web开发人员一起工作时，他给我发送wsdl时，我总是尖叫。因为我将不得不开始一场教育活动，告诉他们为什么这行不通，为什么他们必须学习REST。

SOAP体现了Web服务的面向服务的方法——在这种方法中，方法(或动词)是与服务交互的主要方式。REST采用面向资源的方法，其中对象(或名词)占据中心位置。

快速了解一下2012年的问题:

REST在以下方面发挥了很好的作用:

Limited bandwidth and resources. Remember the return structure is really in any format (developer defined). Plus, any browser can be used because the REST approach uses the standard GET, PUT, POST, and DELETE verbs. Again, remember that REST can also use the XMLHttpRequest object that most modern browsers support today, which adds an extra bonus of AJAX. Totally stateless operations. If an operation needs to be continued, then REST is not the best approach and SOAP may fit it better. However, if you need stateless CRUD (Create, Read, Update, and Delete) operations, then REST is it. Caching situations. If the information can be cached because of the totally stateless operation of the REST approach, this is perfect.That covers a lot of solutions in the above three.

那么我为什么要考虑SOAP呢?同样，SOAP是相当成熟和定义良好的，并且带有完整的规范。REST方法就是这样一种方法，它对开发非常开放，所以如果你具备以下条件，那么SOAP就是一个很好的解决方案:

Asynchronous processing and invocation. If your application needs a guaranteed level of reliability and security then SOAP 1.2 offers additional standards to ensure this type of operation. Things like WSRM – WS-Reliable Messaging. Formal contracts. If both sides (provider and consumer) have to agree on the exchange format then SOAP 1.2 gives the rigid specifications for this type of interaction. Stateful operations. If the application needs contextual information and conversational state management then SOAP 1.2 has the additional specification in the WS* structure to support those things (Security, Transactions, Coordination, etc). Comparatively, the REST approach would make the developers build this custom plumbing.

http://www.infoq.com/articles/rest-soap-when-to-use-each