Overview: Refers to the constraints and specifications for communication between the server and the client. The data interaction between the client and the server is not messy and needs to follow (based on) certain specifications.
Common protocols:
a) HTTP、HTTPS 超文本傳輸協(xié)議 b) FTP 文件傳輸協(xié)議 c) SMTP 簡單郵件傳輸協(xié)議
This article mainly introduces the http hypertext transfer protocol.
1. HTTP protocol
is the Hypertext Transfer Protocol. The website is based on the HTTP protocol. For example, the images, CSS, JS, etc. of the website are all transmitted based on the HTTP protocol. The HTTP protocol is constrained and standardized by the request (Request) from the client to the server and the response (Response) from the server to the client. Commonly used request methods are: GET, POST, PUT, DELETE. 2. Request -Request message:
a) The request is initiated by the client, and its standard format is: request line, request header, and request body. For example:
b) Request message line: composed of request method, request URL and protocol version
c) Request message headerHost:localhost請求的主機 Cache-Control:max-age=0控制緩存(no-cache| no-store) Accept:*/* 接受的文檔MIME類型 User-Agent:向訪問網站提供你所使用的瀏覽器類型、操作系統(tǒng)及版本、CPU 類型、瀏覽器渲染引擎、瀏覽器語言、瀏覽器插件等信息的標識. 瀏覽器UA 字串的標準格式為: 瀏覽器標識 (操作系統(tǒng)標識; 加密等級標識; 瀏覽器語言) 渲染引擎標識 版本信息 Referer:從哪個URL跳轉過來的 Accept-Encoding:可接受的壓縮格式

d) Request message body: that is passed to the server Data
Note: When submitting the form in the form of post, Content-Type: application/x-www-form-urlencoded will be set in the request header, but this setting is not required when requesting in the form of get
3. Response -Response message:
a) The response is sent by the server, and its standard format is: status line, response header, response body
b) Response header:Date:響應時間 Server:服務器信息 Content-Length:響應主體長度 Content-Type:響應資源的MIME類型

c) Response body: that is Content returned by the server to the client
d) Status code:
Common status codes are: 200---The server successfully returned the web page, 304---The document has not been modified, 403---No permission, 404 ---The requested web page does not exist, 500---server error, 503---service unavailableExplanation: The client and server transmit data in byte form, which can be understood as text Form transmission, then the browser needs to know clearly how to parse these text-form data. MIME clearly tells the browser how to process it

Hot AI Tools

Undress AI Tool
Undress images for free

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

HTTP status code 520 means that the server encountered an unknown error while processing the request and cannot provide more specific information. Used to indicate that an unknown error occurred when the server was processing the request, which may be caused by server configuration problems, network problems, or other unknown reasons. This is usually caused by server configuration issues, network issues, server overload, or coding errors. If you encounter a status code 520 error, it is best to contact the website administrator or technical support team for more information and assistance.

How to use NginxProxyManager to implement automatic jump from HTTP to HTTPS. With the development of the Internet, more and more websites are beginning to use the HTTPS protocol to encrypt data transmission to improve data security and user privacy protection. Since the HTTPS protocol requires the support of an SSL certificate, certain technical support is required when deploying the HTTPS protocol. Nginx is a powerful and commonly used HTTP server and reverse proxy server, and NginxProxy

HTTP status code 403 means that the server rejected the client's request. The solution to http status code 403 is: 1. Check the authentication credentials. If the server requires authentication, ensure that the correct credentials are provided; 2. Check the IP address restrictions. If the server has restricted the IP address, ensure that the client's IP address is restricted. Whitelisted or not blacklisted; 3. Check the file permission settings. If the 403 status code is related to the permission settings of the file or directory, ensure that the client has sufficient permissions to access these files or directories, etc.

Understand the meaning of HTTP 301 status code: common application scenarios of web page redirection. With the rapid development of the Internet, people's requirements for web page interaction are becoming higher and higher. In the field of web design, web page redirection is a common and important technology, implemented through the HTTP 301 status code. This article will explore the meaning of HTTP 301 status code and common application scenarios in web page redirection. HTTP301 status code refers to permanent redirect (PermanentRedirect). When the server receives the client's

HTTP Status Code 200: Explore the Meaning and Purpose of Successful Responses HTTP status codes are numeric codes used to indicate the status of a server's response. Among them, status code 200 indicates that the request has been successfully processed by the server. This article will explore the specific meaning and use of HTTP status code 200. First, let us understand the classification of HTTP status codes. Status codes are divided into five categories, namely 1xx, 2xx, 3xx, 4xx and 5xx. Among them, 2xx indicates a successful response. And 200 is the most common status code in 2xx

Quick Application: Practical Development Case Analysis of PHP Asynchronous HTTP Download of Multiple Files With the development of the Internet, the file download function has become one of the basic needs of many websites and applications. For scenarios where multiple files need to be downloaded at the same time, the traditional synchronous download method is often inefficient and time-consuming. For this reason, using PHP to download multiple files asynchronously over HTTP has become an increasingly common solution. This article will analyze in detail how to use PHP asynchronous HTTP through an actual development case.

Explore the causes and solutions of HTTP status code 404 Introduction: In the process of browsing the web, we often encounter HTTP status code 404. This status code indicates that the server was unable to find the requested resource. In this article, we will explore the causes of HTTP status code 404 and share some solutions. 1. Reasons for HTTP status code 404: 1.1 Resource does not exist: The most common reason is that the requested resource does not exist on the server. This may be caused by the file being accidentally deleted, incorrectly named, incorrectly pathed, etc.

Common network communication and security problems and solutions in C# In today's Internet era, network communication has become an indispensable part of software development. In C#, we usually encounter some network communication problems, such as data transmission security, network connection stability, etc. This article will discuss in detail common network communication and security issues in C# and provide corresponding solutions and code examples. 1. Network communication problems Network connection interruption: During the network communication process, the network connection may be interrupted, which may cause
