net/http 01

用 net/http 包可以快速起一个 web 服务

package main

import (
    "fmt"
    "net/http"
)

func helloWorld(w http.ResponseWriter, req *http.Request) {
    _, err := fmt.Fprintf(w, "Hello world!")
    if err != nil {
        fmt.Println("code: 500")
    }
}

func main() {
    http.HandleFunc("/hello", helloWorld)
    err := http.ListenAndServe("0.0.0.0:8080", nil)
    if err != nil {
        fmt.Println("Listen is failed", err)
    }
}

用 net/http 作为 http client 发起 get 请求

• 不带参数的请求

func Req() {
    resp, err := http.Get("https://www.cnblogs.com/")
    if err != nil {
        fmt.Println("Requests is failed")
    }
    defer resp.Body.Close() // 从 response 读取响应内容之后必须关闭
    body, _ := io.ReadAll(resp.Body)
    fmt.Println(string(body))
}

• 带参数的请求需要用 net/url 包

func ReqParser() {
    // base url
    baseURL := "https://baijiahao.baidu.com/s"
    // params
    params := url.Values{}
    params.Set("id", "1775182904014714278")
    params.Set("wfr", "spider")
    params.Set("for", "pc")

    u, err := url.ParseRequestURI(baseURL) // url.ParseRequestURI 可以将原始的 url 解析为 url 结构
    if err != nil {
        fmt.Printf("host:%s is failed err:%s", u.Host, err)
    }
    u.RawQuery = params.Encode() // url 参数 encode
    rawURL := u.String()
    fmt.Println(rawURL) // https://baijiahao.baidu.com/s?for=pc&id=1775182904014714278&wfr=spider

    resp, err := http.Get(rawURL)
    defer resp.Body.Close()
    fmt.Println(resp.Header)            // response header
    content, _ := io.ReadAll(resp.Body) // body
    fmt.Println(string(content))
}


func ReqParser01() {
    // https://hanyu.baidu.com/shici/detail?from=aladdin&pid=aab6b2ffc6a64abb8c7afb5ad1bad000
    endpoint := "https://hanyu.baidu.com/shici/detail"
    client := &http.Client{Timeout: time.Second * 3}         // 自定义 http client, 并设置超时时间
    req, _ := http.NewRequest(http.MethodGet, endpoint, nil) // 创建 request 对象
    params := url.Values{}
    params.Add("from", "aladdin")
    params.Add("pid", "aab6b2ffc6a64abb8c7afb5ad1bad000")
    req.URL.RawQuery = params.Encode()
    req.Header.Add("User-Agent", "xxx-uuu")  // 自定义 UA
    resp, _ := client.Do(req)
    defer resp.Body.Close()
    byte, _ := io.ReadAll(resp.Body)
    fmt.Println(string(byte))
}

用 net/http 作为 http client 发起 post 请求

func reqPost() {
    url := "http://172.22.143.197:8080/recv"
    data := `{"name": "siri", "address": "HK"}`
    // strings.NewReader 将一个字符串转换为实现io.Reader接口的类型
    resp, _ := http.Post(url, "application/json", strings.NewReader(data))
    defer resp.Body.Close()
    content, _ := io.ReadAll(resp.Body) // body
    fmt.Println(string(content))
    fmt.Println(resp.Header)
}


func reqPost01() {
    endpoint := "http://172.22.143.197:8080/recv"
    data := struct {
        name string
        age  int
    }{
        name: "siri",
        age:  16,
    }
    payload, _ := json.Marshal(data)
    // bytes.NewReader 将一个 byte 类型转换为实现 io.Reader 接口的类型
    http.Post(endpoint, "application/json", bytes.NewReader(payload))

}

服务端接收 request.data

func Receiver(w http.ResponseWriter, req *http.Request) {
    defer req.Body.Close()
    byte, err := io.ReadAll(req.Body)
    if err != nil {
        fmt.Printf("request data is failed!, err:%s", err)
        return
    }
    fmt.Println(string(byte))

    w.Header().Set("Content-Type", "application/json")
    w.WriteHeader(http.StatusOK)
    return
}

func main() {
    http.HandleFunc("/recv", Receiver)
    err := http.ListenAndServe("0.0.0.0:8080", nil)
    if err != nil {
        fmt.Println("Listen is failed", err)
    }
}