go 实现简单的http web服务

package main

import (
        "fmt"
        "net/http"
)

func hello(w http.ResponseWriter, r *http.Request) {
        fmt.Println("handle hello")
        fmt.Fprintf(w, "hello12345")
}

func index (w http.ResponseWriter, r *http.Request) {
        //Fprintf根据format参数生成格式化的字符串并写入w。返回写入的字节数和遇到的任何错误
        fmt.Fprintf(w, "this is index")
}

func main () {
        //HandleFunc注册一个处理器函数handler和对应的模式pattern
        //实现路由功能, hello 为函数名
        http.HandleFunc("/", hello)
        http.HandleFunc("/index", index)
        //ListenAndServe监听srv.Addr指定的TCP地址，并且会调用Serve方法接收到的连接。如果srv.Addr为空字符串，会使用":http"。
        err := http.ListenAndServe("0.0.0.0:8080", nil)

        if err != nil {
                fmt.Println("http listen failed")
        }

}

　　2.客户端

//http 客户端
package main

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

func main () {
        res, err := http.Get("http://www.baidu.com")
        if err != nil {
                fmt.Println("get faield,error:,", err)
                return 
        }

        data, err := ioutil.ReadAll(res.Body)

        if err != nil {
                fmt.Println("read err, error:,", err)
                return
        }

        fmt.Println(string(data))
}

　　3. head请求

//head请求实例子
package main

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

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

func main () {
        for _, v := range url {
                //自己建立客户端
                client := http.Client{
                        Transport: &http.Transport {
                                Dial: func(network, addr string) (net.Conn, error) {
                                        //设置超时时间
                                        timeout := 2 * time.Second
                                        return net.DialTimeout(network, addr, timeout)
                                }, 
                        },
                }

                resp, err := client.Head(v)

                if err != nil {
                        fmt.Println("send head failed, error:", err)
                        continue
                }

                fmt.Printf("head succ, status: %v \n", resp.Status)

        }
}