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Discussion on Golang Web Service

Golang Web development is an important and competitive application, and this summary will look at how to create a simple Web service in Golang.

In cases where a Web framework is not applicable, you can build a Web service using net/ HTTP packages.

  1. Here we usenet/httpCreate a Web service that prints the request URL.
package main

import (
	//"log"
	"fmt"
	"net/http"
)

func main(a) {
	http.HandleFunc("/", handler)
	http.ListenAndServe("localhost:6677".nil)}func handler(w http.ResponseWriter, r *http.Request) {
	fmt.Fprintf(w, "url.path=%q\n", r.URL.Path)  // Output to the file stream
}

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The http.HandleFunc function can be understood as URL routing.

ListenAndServe is at the heart of web service creation.

Handler is an HTTP Request handler that accepts an HTTP. ResponseWriter file stream and an object of type http.Request.

[root@VM-0-5-centos ~]# curl localhost:6677/123
url.path="/123"

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  1. We use the handler function to calculate the number of visits to the URL.

Introduce mutexes in Golang Sync so that only one Goroutine changes the count count if multiple requests exist simultaneously. Learn more about mutex later.

package main

import (
	//"log"
	"fmt"
	"net/http"
	"sync"
)

var count int
var mutex sync.Mutex // Use mutex
func main(a) {
	http.HandleFunc("/", handler)
	http.ListenAndServe("localhost:6677".nil)}func handler(w http.ResponseWriter, r *http.Request) {
	mutex.Lock()
	count++
	mutex.Unlock()
	fmt.Fprintf(w, "request url.path:%q has %d times\n", r.URL.Path, count)
}

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Let’s look at the request result as follows:

[root@VM-0-5-centos ~]# curl localhost:6677/golang
request url.path:"/golang" has 1 times
[root@VM-0-5-centos ~]# curl localhost:6677/golang
request url.path:"/golang" has 2 times
[root@VM-0-5-centos ~]# curl localhost:6677/golang
request url.path:"/golang" has 3 times
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  1. http.RequestType objects in addition toURL.PathIn addition to the propertyMethod,ProtoAnd so on. We’re throughhandlerThe functions are printed separately.
package main

import (
	//"log"
	"fmt"
	"net/http"
	"sync"
)

var count int
var mutex sync.Mutex // Use mutex
func main(a) {
	http.HandleFunc("/", handler)
	http.ListenAndServe("localhost:6677".nil)}func handler(w http.ResponseWriter, r *http.Request) {
	fmt.Fprintf(w, "%s,%s,%s,\n", r.Method, r.URL, r.Proto)
	fmt.Fprintf(w, "host:%q\nremoteaddr:%q\n", r.Host, r.RemoteAddr)
	for k, v := range r.Header {
		fmt.Fprintf(w, "Header[%q]:%q\n", k, v)
	}
	for k, v := range r.Form {
		fmt.Fprintf(w, "Form[%q]:%q\n", k, v)
	}

}
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Create the form and accept it with the following output:

/ / the output of the GET/helloweb, HTTP / 1.1, Host: "localhost: 6677" remoteaddr: "127.0.0.1:58088" Header [" the user-agent "] : [" curl / 7.29.0 "] Header [" Accept "] : [" * / * "] Form[parm1]:hello Form[parm2]:webCopy the code

This is the end of a brief introduction to Golang Web services. Next, I will study the wonderful details and essence of Golang in depth.

Feel free to point out any shortcomings in the comments section.

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