Introduction to HTTP

xampp+Agileone Installation XAMPP, the default installation, has a port occupancy detection tool. HTTP: Hypertext Transfer Protocol. HTML: Hypertext Markup Language. HTTP is clear text transmission, the security is poor, so the banking system to download plug-ins for encryption. is a stateless protocol, HTTP1.1 version. Httpwatch:http analysis tool. Professional Edition. Installed as a browser plugin. Click the Record button and all requests will be recorded. 1XX,2XX,3XX indicates that the request and the server are successful. 4XX indicates a problem with the client request. 5XX indicates a problem on the service side. Request type: Get,post. An HTML page and a picture have a unique location address (URI). Post with file Upload, form submission,

  request: Host:www.baidu.comAccept:  */*  Span style= "COLOR: #008000" >: Receive all types of user-agent:mozilla/5.0 (Windows NT 10.0; WOW64) applewebkit/537.36 (khtml, like Gecko) chrome/65.0.3325.181 safari/537.36: Client version accept-encoding:gzip, deflate, BR: The standard compression that can be handled, the text content is compressed during the transmission process. Compression is done on the server side, and the browser needs to be decompressed. Connection:keep-alive: The network transmission needs to establish the TCP connection, 3 handshake, the resource consumes a lot. Reuse the next time you request the same resource or URL. Keep it for a while, not destroy it immediately. For example, the continuous use of 100 times or the establishment of how long, can be re-established. cookie:bidupsid=6a597eec2f358db1edd8d9a526587b44; pstm=1521630943; baiduid=5ca2e41a7c44264a6bcdeeac093884c3:fg=1; bd_upn=12314753; bdrcvfr[fewj1vr5u3d]=i67x6tjhwwyf0; A cookie is the content that the browser sends to the server, and the content is determined by the browser. X-requested-with:xmlhttprequest:ajax send referer:   https://www.baidu.com/s?wd=tomcat%20%20spring%20  : Which page sends this request and collects the user's visiting records. No referer instructions are direct address access, more loyal. 

Response: Content-type:text/html;charset=utf-8: tells the browser what resources to return. The binary of the data transfer is restored by type. Transfer-encoding:chunked: One-time transmission is not complete, segmented, the browser will be stitched together. There is no length field, and when there is a length field, the client reads the data based on its length and waits for the next response. Connection:keep-Alivecache-control:Private: no-the cache does not need to be cached for each reload of the page. Private is reloaded for the first time and later read from the cache. Expires:thu, -May2028  on: .: -GMT: The expiration time of the cache. The cache is the local hard disk where the page is saved. Many caches are in memory and the browser is cached inside the hard disk. Content-encoding:gzip: Compression format x-ua-compatible:ie=edge,chrome=1: Compatibility mode custom field: Browser's cookie is then sent to the server for use. Cookies are server-side generated, saved in the client set-cookie:bd_ck_sam=1;p ath=/Set-cookie:h_ps_pssid=1469_21104_26350_22072; path=/; domain=. Baidu.comset-cookie:bdsvrtm= -; path=/Set-cookie:psino=6; domain=.baidu.com; path=/Keep-alive:timeout=5, max= -: After 5 seconds or the connection is used 100 times, a new connection is created

Session: Set-cookie:serverid=34e1ee01aa40e94e2474dffd938824db| 1527087303| 1527082184; path=/ServerID uniquely identifies a client, the server generates a unique number, the service side maintains a file, and a column is the ID number. 

When the server assigns a SessionID to the client, the server also generates a file named SessionID.

File Open:

Islogin=trueto indicate that you are logged in. A very large system will produce a hundred thousand of such files. A directory puts hundreds of thousands of files, which are very slow to address. This approach is not recommended for very large systems. These files are stored in memory and not on the hard disk. A database with a memory type exists. Cookie: Whether to save the login information. The browser reads the cookie, carries the account, and the server validates the cookie. When you exit, empty the cookie and the session. Cookie file:

security issues with cookies: Direct Close browser is not logout, then cookies are saved on the client, and deregistration of the cookie can prevent Cookie Disclosure.

The browser comes with the ability to read cookie files. Just add the cookie and you'll be able to log in automatically.

Fiddler Grab Bag tool.

ConnectTimeout: The time-out for the connection.

ReadTimeout: Gets the time of the response when the request goes out.

Getheaderfield ("Set-cookie")//Get service-side multiple cookies

Add cookies from the server to the server in the request

Setrequestproperty ("Cookie", "Username=admin;password=admin")

Introduction to HTTP