HTTP方法的深度探源与RESTful API的设计思想

By heiry on 2026-09-03 in 技术

HTTP认知溯源

HTTP方法本质上就是一个普通的 ASCII 编码字符串，我们可以自定义HTTP方法。从这一点看每个http方法没有什么区别。但是，在应用层，考虑到缓存与网络效能、容错与重试机制、安全隔离与攻击防御等，浏览器、路由器、防火墙、CDN节点、NGINX等应用对各方法做了区别对待。

HTTP方法是在安全和幂等的理念下设计的，语义化的命名有助于互联网生态的协作，在缓存、爬虫、搜索、CDN分发、前后端数据交互等方面能更低成本协作。而REST则是一种设计API的理念，即使用 URI 来标识资源，使用标准的 HTTP 方法 来表示操作。RESTful则是符合这种理念的API。

即使写程序很多年的老鸟，能真正说清楚道明白HTTP方法的也不多，多数都只会使用而不知道所以然。每个人都知道使用GET、POST方法，使用也很熟练，但是底层设计思想并不一定了解。这里，来认真梳理一下HTTP方法背后设计的逻辑。

一. HTTP方法常见10种

HTTP 标准里常见的10 个：

方法主要作用
GET获取资源
POST提交数据 / 创建资源
PUT完整替换资源
PATCH部分修改资源
DELETE删除资源
HEAD获取响应头，不返回正文
OPTIONS查询服务器支持哪些方法/能力
CONNECT建立隧道
TRACE请求回显，用于诊断
QUERY用于查询搜索（2026年RFC10008新增）

（实际上HTTP方法数量多达几十种，这里只是列举常见的方法，详见文末）

二.HTTP方法两个核心设计理念：安全（Safe） 与 幂等（Idempotent）

Safe

Read-only by definition

Request methods are considered “safe” if their defined semantics are essentially read-only; i.e., the client does not request, and does not expect, any state change on the origin server as a result of applying a safe method to a target resource. Likewise, reasonable use of a safe method is not expected to cause any harm, loss of property, or unusual burden on the origin server.

The purpose of distinguishing between safe and unsafe methods is to allow automated retrieval processes (spiders) and cache performance optimization (pre-fetching) to work without fear of causing harm. In addition, it allows a user agent to apply appropriate constraints on the automated use of unsafe methods when processing potentially untrusted content.

查看官方定义

Idempotent

Same effect when repeated

A request method is considered “idempotent” if the intended effect on the server of multiple identical requests with that method is the same as the effect for a single such request.

Idempotent methods are distinguished because the request can be repeated automatically if a communication failure occurs before the client is able to read the server’s response. For example, if a client sends a PUT request and the underlying connection is closed before any response is received, then the client can establish a new connection and retry the idempotent request. It knows that repeating the request will have the same intended effect, even if the original request succeeded, though the response might differ.

查看官方定义

注意：以上的标准是2014年颁布的RFC 7231，QUETY标准出自2026颁布的RFC 10008