2016-1-HTTP (i)

One: Find the server by URL 1. URL concept:

1.1 URL full name uniform Resource Locatior Uniform Resource Locator

1.2 The only resources on the Internet can be found through a single URL.

1.3 A URL corresponds to a unique Internet resource.

2. Basic format of URL: protocol://HOST address/path

such as: Http://www.baidu.com/img/logo.png

Http://202.108.22.5/img/logo.png

2.1 Protocol: Different protocols, representing different ways of finding resources, different ways of transferring resources.

2.2 Host Address: The host (server) IP address (domain name) where the resource resides.

2.3 Path: The exact location of the resource on the host (server).

Common protocols in 3.URL

different protocols mean you're looking for different resources.

1. HTTP

1.1 Hypertext Transfer Protocol, access to remote network resources, the format is HTTP//

1.2 HTTP protocol is the most commonly used protocol in network development.

2. File

2.1 Access to the file on the local computer, no IP address, format: file://

3. Maito

3.1 Access is the e-mail address, format: mailto:

4. FTP

4.1 Access to the file on the shared host, format: ftp://

Two: Introduction to HTTP protocol

1. Both mobile and PC-side, access to remote network resources often uses the HTTP protocol.

Role of the 2.HTTP protocol:

2.1 Specifies the data transfer format between the client and server, which means that the server and the client are required to comply with the HTTP protocol when transmitting data.

2.2 To enable the client and the server to effectively communicate data.

Third: The communication process of the HTTP protocol

1. The complete HTTP communication process is divided into two main steps:

1.1 Request: The client asks for data from the server.

1.2 Response: The server returns the appropriate data to the client.

2016-1-HTTP (i)