How to implement cookies in golang
In web development, cookies are a very common technology used to store some information about the user for use in subsequent requests.
Go language (golang) also provides complete cookie support, which can easily read and set cookies in HTTP requests and responses.
This article will introduce how golang implements cookies and provide some sample code so that readers can better understand. The following is a detailed introduction.
1. Cookies in golang
In golang, the Cookie type of the http package is used to represent a cookie. A cookie contains two fields: Key and Value, as well as some optional fields, such as Path, Domain, MaxAge, Expires, etc.
The following is the definition of Cookie:
type Cookie struct {
Name string Value string Path string Domain string Expires time.Time RawExpires string MaxAge int Secure bool HttpOnly bool Raw string Unparsed []string
}
The meaning of each field of Cookie is as follows:
- Name: The name of the cookie
- Value: The value of the cookie
- Path: The valid request URL path of the cookie
- Domain: The host name of the valid request URL of the cookie
- Expires: The expiration time of the cookie
- MaxAge: The expiration time of the cookie, in seconds
- Secure: The cookie is only transmitted in HTTPS connections
- HttpOnly : The cookie cannot be accessed by JavaScript
- Raw: The original string of the cookie in the HTTP request
- Unparsed: The unprocessed cookie string
2. Set cookies
In golang, to set a cookie, you can use the SetCookie function of the http package. The SetCookie function requires a parameter of type ResponseWriter, which is used to send an HTTP response to the client.
The following is the definition of the SetCookie function:
func SetCookie(w ResponseWriter, cookie *Cookie)
In the sample code, we will set a name named "username" cookie and set its value to "john".
The sample code is as follows:
package main
import (
"net/http"
)
func main() {
http.HandleFunc("/", handler) http.ListenAndServe(":8080", nil)
}
func handler(w http.ResponseWriter, r *http.Request) {
c := http.Cookie{Name: "username", Value: "john"} http.SetCookie(w, &c)
}
3. Read cookie
In In golang, to read a cookie, you can use the Cookies function of the http package. The Cookies function requires a parameter of type Request, which is used to represent HTTP requests.
The following is the definition of the Cookies function:
func Cookies(r Request) []Cookie
In the sample code, we will read before Sets a cookie named "username" and prints its value to the console.
The sample code is as follows:
package main
import (
"fmt" "net/http"
)
func main() {
http.HandleFunc("/", handler) http.ListenAndServe(":8080", nil)
}
func handler(w http.ResponseWriter, r *http.Request) {
c, err := r.Cookie("username") if err != nil { fmt.Println("Unable to read cookie") } else { fmt.Println(c.Value) }
}
This sample code uses the Cookie method of Request to read A cookie named "username". If the read is successful, the cookie value is output; otherwise, an error message is output.
Summary
This article introduces how to use cookies in golang, including how to create and read cookies. Through the introduction of this article, readers can master the basic usage of cookies in golang, providing more possibilities for web development.
The above is the detailed content of How to implement cookies in golang. For more information, please follow other related articles on the PHP Chinese website!

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