Understand restful architecture

1.REST

RESTful, It is the most popular Internet software architecture at present . Because it's structured 、 Meet the standard 、 Easy to understand 、 Easy to expand , So more and more websites are using .

1.1. What is? REST

REST Refers to a set of architectural constraints and principles . An application or design that satisfies these constraints and principles is RESTful Of .
REST A few concepts ：

• resources REST yes “ Represent layer state transformation ”.“ The presentation layer ” refer to “ resources ” The performance layer of ;
• The presentation layer ： A resource is a specific entity information , There can be many ways to show , Showing entities is the presentation layer ;
• State transformation ： Visit a website , It represents an interactive process between the client and the server , This process involves the transformation of data and state ;

2.RESTful framework

RESTful The architecture needs to meet the following conditions ：

• Every URL Represents a resource ;
• Between client and server , A layer of expression that conveys this resource ;
• Client pass HTTP Verb , Operate the server-side resources , Realization ” Expression layer transformation “;

Web The application should satisfy REST The most important principle is : The interaction between client and server is stateless between requests , That is, every request from the client to the server must contain the necessary information to understand the request . If the server restarts at any point in time between requests , The client will not be notified . In addition, this request can be answered by any available server , It's perfect for environments like cloud computing . Because it's stateless , So clients can cache data to improve performance . Another important thing REST The principle is system layering , This means that the component cannot understand any component other than the hierarchy it interacts with directly . By limiting system knowledge to a single layer , Can limit the complexity of the entire system , This promotes the independence of the bottom layer .

Realization RESTful Application design of

package main
import (
    "fmt"
    "log"
    "net/http"
    "github.com/julienschmidt/httprouter"
)
func Index(w http.ResponseWriter, r *http.Request, _ httprouter.Params) {
    
    fmt.Fprint(w, "Welcome!\n")
}
func Hello(w http.ResponseWriter, r *http.Request, ps httprouter.Params) {
    
    fmt.Fprintf(w, "hello, %s!\n", ps.ByName("name"))
}
func getuser(w http.ResponseWriter, r *http.Request, ps httprouter.Params) {
    
    uid := ps.ByName("uid")
    fmt.Fprintf(w, "you are get user %s", uid)
}
func modifyuser(w http.ResponseWriter, r *http.Request, ps httprouter.Params) {
    
    uid := ps.ByName("uid")
    fmt.Fprintf(w, "you are modify user %s", uid)
}
func deleteuser(w http.ResponseWriter, r *http.Request, ps httprouter.Params) {
    
    uid := ps.ByName("uid")
    fmt.Fprintf(w, "you are delete user %s", uid)
}
func adduser(w http.ResponseWriter, r *http.Request, ps httprouter.Params) {
    
    // uid := r.FormValue("uid")
    uid := ps.ByName("uid")
    fmt.Fprintf(w, "you are add user %s", uid)
}
func main() {
    
    router := httprouter.New()
    router.GET("/", Index)
    router.GET("/hello/:name", Hello)
    router.GET("/user/:uid", getuser)
    router.POST("/adduser/:uid", adduser)
    router.DELETE("/deluser/:uid", deleteuser)
    router.PUT("/moduser/:uid", modifyuser)
    log.Fatal(http.ListenAndServe(":8080", router))
}

summary
REST It's an architectural style , Absorbed WWW Experience of success ： No state , Resource centric , make the best of HTTP The protocol and URI agreement , Provide a unified interface definition , Make it a design Web The service method has become popular . In a sense , By emphasizing URI and HTTP And so on Internet standard ,REST Before the era of large application servers Web The return of ways . at present Go about REST It's still very simple , By implementing custom routing rules , We can do it for different method Make a difference handle, That's it REST The architecture of .