Detailed explanation of http messages

HTTP Working Principle HTTP messages are roughly divided into two parts: message header and message body, which are divided by blank lines in the middle.

Usually, there is not necessarily a message body.

For example, enter www.baidu.com in the browser address bar, open the console, view Request Headers, and see the following information: The first line is the request line: GET / HTTP/1.1 The method is GET. In the example of the protocol version, control

Click on Response, and we can see the data returned by the server to the browser (as shown in the picture). The data format is html. After the browser gets the data, it parses and renders it into the Baidu homepage we see.

Enter the data we want to search in Baidu's search bar. For example, I entered Encyclopedia, refresh and observe the message information given by Network. We will find that there is a string of data behind the request header (Request Headers). Query String Parameters (query characters)

String parameter list), as shown in the figure, this means that when we want to query some data, the browser packages the queried data information into an HTTP request message and sends it to the server.