发送Get请求

package main

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

func main() {
   url := "http://apis.juhe.cn/simpleWeather/query?key=087d7d10f700d20e27bb753cd806e40b&city=北京"
   resp, err := http.Get(url)
   if err != nil {
      log.Fatal(err)
   }
   defer resp.Body.Close()
   b, _ := ioutil.ReadAll(resp.Body)
   fmt.Printf("b: %v\n", string(b))
}

GET请求，将参数做成变量

package main

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

func main() {
   param := url.Values{}
   url, err := url.Parse("http://apis.juhe.cn/simpleWeather/query")
   if err != nil {
      return
   }
   param.Set("key", "087d7d10f700d20e27bb753cd806e40b")
   param.Set("city", "北京")
   url.RawQuery = param.Encode()
   urlPath := url.String()
   fmt.Println(urlPath)
   resp, err := http.Get(urlPath)
   if err != nil {
      log.Fatal(err)
   }
   defer resp.Body.Close()
   body, _ := ioutil.ReadAll(resp.Body)
   fmt.Println(string(body))
}

解析JSON类型返回结果

package main

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

func main() {
   type result struct {
      Args    string            `json:"args"`
      Headers map[string]string `json:"headers"`
      Origin  string            `json:"origin"`
      Url     string            `json:"url"`
   }
   resp, err := http.Get("http://httpbin.org/get")
   if err != nil {
      return
   }
   defer resp.Body.Close()
   body, _ := ioutil.ReadAll(resp.Body)
   fmt.Println(string(body))
   var res result
   _ = json.Unmarshal(body, &res)
   fmt.Printf("%#v", res)
}

GET请求添加请求头

package main

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

func main() {
   client := http.Client{}
   req, _ := http.NewRequest("GET", "http://httpbin.org/get", nil)
   req.Header.Add("name", "牛牛")
   req.Header.Add("age", "18")
   resp, _ := client.Do(req)
   body, _ := ioutil.ReadAll(resp.Body)
   fmt.Printf(string(body))
}

发送POST请求

package main

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

func main() {
   path := "http://apis.juhe.cn/simpleWeather/query"
   urlValues := url.Values{}
   urlValues.Add("key", "087d7d10f700d20e27bb753cd806e40b")
   urlValues.Add("city", "北京")
   r, err := http.PostForm(path, urlValues)
   if err != nil {
      log.Fatal(err)
   }
   defer r.Body.Close()
   b, _ := ioutil.ReadAll(r.Body)
   fmt.Printf("b: %v\n", string(b))
}

另一种方式

package main

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

func main() {
   urlValues := url.Values{
      "name": {"牛牛"},
      "age":  {"18"},
   }
   reqBody := urlValues.Encode()
   resp, _ := http.Post("http://httpbin.org/post", "text/html", strings.NewReader(reqBody))
   body, _ := ioutil.ReadAll(resp.Body)
   fmt.Println(string(body))
}

JSON格式的POST请求

package main

import (
   "bytes"
   "encoding/json"
   "fmt"
   "io/ioutil"
   "net/http"
)

func main() {
   data := make(map[string]interface{})
   data["site"] = "www.duoke360.com"
   data["name"] = "多课网"
   bytesData, _ := json.Marshal(data)
   resp, _ := http.Post("http://httpbin.org/post", "application/json", bytes.NewReader(bytesData))
   body, _ := ioutil.ReadAll(resp.Body)
   fmt.Println(string(body))
}

使用Client自定义请求

package main

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

func main() {
   client := http.Client{
      Timeout: time.Second * 5,
   }
   url := "http://apis.juhe.cn/simpleWeather/query?key=087d7d10f700d20e27bb753cd806e40b&city=北京"
   req, err := http.NewRequest(http.MethodGet, url, nil)
   if err != nil {
      log.Fatal(err)
   }
   req.Header.Add("referer", "http://apis.juhe.cn/")
   res, err2 := client.Do(req)
   if err2 != nil {
      log.Fatal(err2)
   }
   defer res.Body.Close()
   b, _ := ioutil.ReadAll(res.Body)
   fmt.Printf("b: %v\n", string(b))
}

HTTP Server

package main

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

func main() {
   // 请求处理函数
   f := func(resp http.ResponseWriter, req *http.Request) {
      io.WriteString(resp, "hello world")
   }
   // 响应路径,注意前面要有斜杠 /
   http.HandleFunc("/hello", f)
   // 设置监听端口，并监听，注意前面要有冒号:
   err := http.ListenAndServe(":9999", nil)
   if err != nil {
      log.Fatal(err)
   }
}

使用Handler实现并发处理

package main

import (
   "fmt"
   "log"
   "net/http"
   "sync"
)
//统计访问次数
type countHandler struct {
   mu sync.Mutex // guards n
   n  int
}

func (h *countHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
   h.mu.Lock()
   defer h.mu.Unlock()
   h.n++
   fmt.Fprintf(w, "count is %d\n", h.n)
}

func main() {
   http.Handle("/count", new(countHandler))
   log.Fatal(http.ListenAndServe(":8080", nil))
}