它们似乎都在向身体内部的服务器发送数据,那么它们有什么不同呢?


当前回答

请参阅:http://zacharyvoase.com/2009/07/03/http-post-put-diff/

最近,我对web开发人员的一个流行误解感到非常恼火,他们认为POST是用来创建资源的,而PUT是用来更新/更改资源的。

如果你看一下RFC 2616的第55页(“超文本传输协议- HTTP/1.1”),第9.6节(“PUT”),你会看到PUT实际上是干什么的:

PUT方法要求将所包含的实体存储在所提供的Request-URI下。

还有一个方便的段落解释了POST和PUT之间的区别:

The fundamental difference between the POST and PUT requests is reflected in the different meaning of the Request-URI. The URI in a POST request identifies the resource that will handle the enclosed entity. That resource might be a data-accepting process, a gateway to some other protocol, or a separate entity that accepts annotations. In contrast, the URI in a PUT request identifies the entity enclosed with the request – the user agent knows what URI is intended and the server MUST NOT attempt to apply the request to some other resource.

它没有提到更新/创建之间的区别,因为这不是它的重点。这是关于这两者之间的区别:

obj.set_attribute(value) # A POST request.

这:

obj.attribute = value # A PUT request.

所以,请停止这种流行的误解的传播。阅读rfc。

其他回答

其他人已经发布了很好的答案,我只是想补充一点,在大多数语言、框架和用例中,你会更多地使用POST,而不是PUT。PUT、DELETE等基本都是鸡毛蒜毛的问题。

根据HTTP方法定义操作

HTTP协议定义了许多为请求分配语义的方法。大多数RESTful web api使用的常见HTTP方法有:

GET在指定URI处检索资源的表示形式。响应消息的主体包含所请求资源的详细信息。

POST在指定的URI上创建一个新资源。请求消息的主体提供了新资源的详细信息。注意,POST还可以用于触发不实际创建资源的操作。

PUT在指定的URI上创建或替换资源。请求消息的主体指定要创建或更新的资源。

PATCH执行资源的部分更新。请求体指定要应用于资源的更改集。

DELETE删除指定URI上的资源。

特定请求的效果应取决于资源是集合还是单个项。下表通过电子商务示例总结了大多数RESTful实现采用的常见约定。并不是所有这些请求都可以实现——这取决于具体的场景。

Resource POST GET PUT DELETE
/customers Create a new customer Retrieve all customers Bulk update of customers Remove all customers
/customers/1 Error Retrieve the details for customer 1 Update the details of customer 1 if it exists Remove customer 1
/customers/1/orders Create a new order for customer 1 Retrieve all orders for customer 1 Bulk update of orders for customer 1 Remove all orders for customer 1

POST、PUT和PATCH之间的区别可能令人困惑。

POST请求创建一个资源。服务器为新资源分配URI,并将该URI返回给客户端。在REST模型中,您经常对集合应用POST请求。新资源被添加到集合中。POST请求还可以用于将数据提交到现有资源进行处理,而不需要创建任何新资源。

A PUT request creates a resource or updates an existing resource. The client specifies the URI for the resource. The request body contains a complete representation of the resource. If a resource with this URI already exists, it is replaced. Otherwise, a new resource is created, if the server supports doing so. PUT requests are most frequently applied to resources that are individual items, such as a specific customer, rather than collections. A server might support updates but not creation via PUT. Whether to support creation via PUT depends on whether the client can meaningfully assign a URI to a resource before it exists. If not, then use POST to create resources and PUT or PATCH to update.

PATCH请求对现有资源执行部分更新。客户端为资源指定URI。请求体指定要应用于资源的一组更改。这可能比使用PUT更有效,因为客户端只发送更改,而不是资源的整个表示。从技术上讲,如果服务器支持的话,PATCH还可以创建一个新资源(通过指定一组对“null”资源的更新)。

PUT请求必须是等幂的。如果客户端多次提交相同的PUT请求,结果应该总是相同的(相同的资源将被修改为相同的值)。POST和PATCH请求不能保证是等幂的。

请参阅:http://zacharyvoase.com/2009/07/03/http-post-put-diff/

最近,我对web开发人员的一个流行误解感到非常恼火,他们认为POST是用来创建资源的,而PUT是用来更新/更改资源的。

如果你看一下RFC 2616的第55页(“超文本传输协议- HTTP/1.1”),第9.6节(“PUT”),你会看到PUT实际上是干什么的:

PUT方法要求将所包含的实体存储在所提供的Request-URI下。

还有一个方便的段落解释了POST和PUT之间的区别:

The fundamental difference between the POST and PUT requests is reflected in the different meaning of the Request-URI. The URI in a POST request identifies the resource that will handle the enclosed entity. That resource might be a data-accepting process, a gateway to some other protocol, or a separate entity that accepts annotations. In contrast, the URI in a PUT request identifies the entity enclosed with the request – the user agent knows what URI is intended and the server MUST NOT attempt to apply the request to some other resource.

它没有提到更新/创建之间的区别,因为这不是它的重点。这是关于这两者之间的区别:

obj.set_attribute(value) # A POST request.

这:

obj.attribute = value # A PUT request.

所以,请停止这种流行的误解的传播。阅读rfc。

值得一提的是,POST容易受到一些常见的跨站请求伪造(CSRF)攻击,而PUT则不会。

当受害者访问attackersite.com时,下面的CSRF是不可能的。

攻击的效果是,受害者无意中删除一个用户,只是因为它(受害者)在访问attackersite.com之前以admin身份登录target.site.com:

attackersite.com上的恶意代码:

案例1:正常请求。保存的target.site.com cookie将自动由浏览器发送:(注意:只支持PUT,在端点,是更安全的,因为它是不支持<form>属性值)

<!--deletes user with id 5-->
<form id="myform" method="post" action="http://target.site.com/deleteUser" >
    <input type="hidden" name="userId" value="5">
</form>
<script>document.createElement('form').submit.call(document.getElementById('myform'));</script>

案例2:XHR请求。保存的target.site.com cookie将被浏览器自动发送:(注意:只支持PUT,在端点,是更安全的,因为尝试发送PUT将触发一个preflight请求,其响应将阻止浏览器请求deleteUser页面)

//deletes user with id 5
var xhr = new XMLHttpRequest();
xhr.open("POST", "http://target.site.com/deleteUser");
xhr.withCredentials=true;
xhr.send(["userId=5"]);

MDN Ref: [..]与“简单请求”(上面讨论过)不同,——[[意思是:POST/GET/HEAD]]——,对于“预飞行”请求,浏览器首先使用OPTIONS方法发送一个HTTP请求[..]

Cors在行动:[..]某些类型的请求,如DELETE或PUT,在发出实际请求之前需要进一步请求服务器的许可。]所谓的飞行前请求[..]

GET: Retrieves data from the server. Should have no other effect. PUT: Replaces target resource with the request payload. Can be used to update or create a new resource. PATCH: Similar to PUT, but used to update only certain fields within an existing resource. POST: Performs resource-specific processing on the payload. Can be used for different actions including creating a new resource, uploading a file, or submitting a web form. DELETE: Removes data from the server. TRACE: Provides a way to test what the server receives. It simply returns what was sent. OPTIONS: Allows a client to get information about the request methods supported by a service. The relevant response header is Allow with supported methods. Also used in CORS as preflight request to inform the server about actual the request method and ask about custom headers. HEAD: Returns only the response headers. CONNECT: Used by the browser when it knows it talks to a proxy and the final URI begins with https://. The intent of CONNECT is to allow end-to-end encrypted TLS sessions, so the data is unreadable to a proxy.