Http编程

http编程

  • Go原生支持http：import("net/http")

  • Go的http服务性能和nginx比较接近

  • 几行代码就可以实现一个web服务

import (
	"fmt"
	"net/http"
)

func Hello(w http.ResponseWriter, r *http.Request) {
	fmt.Println("handle hello")
	fmt.Fprint(w, "hello")
}

func Login(w http.ResponseWriter, r *http.Request) {
	fmt.Println("handle hello")
	fmt.Fprint(w, "login")
}

func main() {
	http.HandleFunc("/", Hello)   // 匹配路由，执行对应的方法
	http.HandleFunc("/login", Login)
	err := http.ListenAndServe("127.0.0.1:8000", nil)
	if err != nil {
		fmt.Println("http listen failed")
	}
}

http client

import (
	"fmt"
	"io/ioutil"
	"net/http"
)

func main() {
	resp, err := http.Get("https://www.baidu.com/")
	if err != nil {
		fmt.Println("get err:", err)
		return
	}
	bytes, e := ioutil.ReadAll(resp.Body)
	if e != nil {
		fmt.Println("get data err:", e)
		return
	}
	// 打印获取的结果
	fmt.Println(string(bytes))
}

head请求

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

var url = []string{
	"https://www.baidu.com",
	"http://google.com",
	"http://taobao.com",
}

func main() {
	for _, v := range url {
		// 自定义超时时间 2秒
		c := http.Client{
			Transport: &http.Transport{
				Dial: func(network, addr string) (net.Conn, error) {
					timeout := time.Second * 2
					return net.DialTimeout(network, addr, timeout)
				},
			},
		}
		// 请求
		resp, err := c.Head(v)
		if err != nil {
			fmt.Printf("head %s faild, err: %v\n", v, err)
			continue
		}
		fmt.Printf("head success, status： %v\n", resp.Status)
	}
}

panic处理

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

func Hello(w http.ResponseWriter, r *http.Request) {
	fmt.Println("handle hello")
	fmt.Fprint(w, "hello")
}

func Login(w http.ResponseWriter, r *http.Request) {
	fmt.Println("handle hello")
	fmt.Fprint(w, "login")
}

func main() {
	http.HandleFunc("/", Panics(Hello))   // 匹配路由，执行对应的方法
	http.HandleFunc("/login", Panics(Login))
	err := http.ListenAndServe("127.0.0.1:8000", nil)
	if err != nil {
		fmt.Println("http listen failed")
	}
}

// 错误处理函数
func Panics(handle http.HandlerFunc) http.HandlerFunc {
	return func(writer http.ResponseWriter, request *http.Request) {
		// 出错走这里
		defer func() {
			if e := recover(); e != nil {
				log.Printf("[%v] caught panic: %v", request.RemoteAddr, e)
			}
		}()
		// 正常执行
		handle(writer, request)
	}
}

模板

go

import (
	"fmt"
	"html/template"
	"os"
)

type Person struct {
	Name string
	age int
}

func main() {
	// 读取html文件
	temp, e := template.ParseFiles("src/go_dev/template/main/index.html")
	if e != nil {
		fmt.Println("parse file err:", e)
		return
	}
	person := Person{Name: "Marry", age: 18}
	// 将person对象传入进行渲染
	if err := temp.Execute(os.Stdout, person); err != nil {
		fmt.Println("There was an error:", err.Error())
	}
}

1. 替换{{ .字段名 }}

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <!-- 通过{{.Name}}获取person里面的name，.就表示person对象 -->
    <h1>hello, {{.Name}}</h1>
</body>
</html>

2. if判断

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    {{if gt .Age 18}}
        <p>hello 18</p>
    {{else}}
        <p>hello 19</p>
    {{end}}
</body>
</html>

3. {{with .Var}}

使用with可以将指定的变量用.代替

{{with .Name}}
    <!-- 此时的{{.}}就是{{.Name}} -->
	<p>{{.}}</p>
{{end}}

4. 循环

{{range .}}
    <p>{{.Name}}</p>
{{end}}

 

posted @ 2019-05-24 17:43  Jin同学  阅读(149)  评论(0)    收藏  举报