Use Golang's standard library to build a website--5. Processing cookies

This is a creation in Article, where the information may have evolved or changed.

Reasonable use of cookies can greatly improve the user experience of the site, this article is mainly to discuss how to deal with cookies in go.

Statement

The go language is set by the Setcookie in the Net/http package:

To set a method declaration for a cookiehttp.Setcookie(WResponsewriter, Cookies *Cookies)//CookiesThe statementtype Cookiesstruct{Name       string    Value      string    Path       string    Domain     string    Expires     Time. Time    Rawexpires string//MaxAge=0means No'Max- Age'attribute specified. //MaxAge<0means Delete Cookies  Now,equivalently'Max- Age: 0 '//MaxAge>0means Max- Age attribute present  and given inch seconds    MaxAge   int    Secure   BOOL    HttpOnly BOOL    Raw      string    unparsed[]string//Raw text  of unparsed attribute-value Pairs}

How to set the cookie (written in the index method)

tNow := time.Now()cookie := http.Cookie"username""BCL", Expires: tNow.AddDate(100)}http.SetCookie(w, &cookie)

Run it and view the request header in the browser, such as:

The cookie has been successfully set.

Ways to get cookies

The method of obtaining a cookie is also simple:

username, err := r.Cookie("username")

It is important to note that R. The Cookie ("username") does not directly return the value of the username corresponding string type
Instead, a new cookie struct is returned to hold the corresponding value of the username.

Now combine the two steps together to write a complete example of handling cookies:

Read the Cookie and make the appropriate feedback username, err: = R.cookie ("username") FMT. PRINTLN (username, err)ifErr! = Nil {fmt. Println ("No Cookie", err)}//To determine if a cookie has been setifUsername = = Nil {//Set Cookies    Tnow:= Time. Now ()//Set cookies, valid for one yearCookie: =http. Cookie{name:"username", Value:"BCL", Expires:Tnow. Adddate (1,0,0)}http. Setcookie (W, &cookie)}Else{data["visited"] ="Welcome back."+ username. Value}

Run, let's run a look at the effect:
First time visit:

Second visit