go 语言一直是我在部门里进行产品开发的后端选择，也经常会用 golang 进行一些爬虫工作，于是就打算写一篇博客总结一下如何用 golang 发送 http 请求。

GET 请求

基本的 GET 请求

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package main

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

func main() {
    resp, err := http.Get("https://blog.cnpatrickstar.com/get")
    if err != nil {
        fmt.Println(err)
        return
    }
    defer resp.Body.Close()
    body, err := ioutil.ReadAll(resp.Body)
    fmt.Println(string(body))
    fmt.Println(resp.StatusCode)
    if resp.StatusCode == 200 {
        fmt.Println("ok")
    }
}

带参数的 GET 请求

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package main

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

func main(){
    params := url.Values{}
    Url, err := url.Parse("https://blog.cnpatrickstar.com/get")
    if err != nil {
        return
    }
    params.Set("name","patrick")
    params.Set("age","20")
    // 如果参数中有中文参数,这个方法会进行 URLEncode
    Url.RawQuery = params.Encode()
    urlPath := Url.String()
    fmt.Println(urlPath) 
    // https://blog.cnpatrickstar.com/get?age=20&name=patrick
    // 当然也可以直接用拼接好的 url 进行请求，但业务场景下大多还是用变量的形式拼接的
    resp,err := http.Get(urlPath)
    defer resp.Body.Close()
    body, _ := ioutil.ReadAll(resp.Body)
    fmt.Println(string(body))
}

带请求头的 GET 请求

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package main

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

func main() {
    client := &http.Client{}
    req,_ := http.NewRequest("GET","https://blog.cnpatrickstar.com/get",nil)
    req.Header.Add("name","patrick")
    req.Header.Add("age","20")
    resp,_ := client.Do(req)
    body, _ := ioutil.ReadAll(resp.Body)
    fmt.Printf(string(body))
}

解析返回的 JSON

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package main

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

type result struct {
    Args string `json:"args"`
    Headers map[string]string `json:"headers"`
    Origin string `json:"origin"`
    Url string `json:"url"`
}

func main() {
    resp, err := http.Get("https://blog.cnpatrickstar.com/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)
}
POST 请求

基本的 POST 请求

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package main

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

func main() {
    form := url.Values{}
    form.Add("name","patrick")
    form.Add("age","20")
    resp, _ := http.PostForm("https://blog.cnpatrickstar.com/post",form)
    // "Content-Type": "application/x-www-form-urlencoded"
    body, _ := ioutil.ReadAll(resp.Body)
    fmt.Println(string(body))
}

另外一种内容格式：

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package main

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

func main() {
    urlValues := url.Values{
        "name":{"patrick"},
        "age":{"20"},
    }
    reqBody:= urlValues.Encode()
    resp, _ := http.Post("https://blog.cnpatrickstar.com/post", "text/html",strings.NewReader(reqBody))
    //  "Content-Type": "text/html"
    body,_:= ioutil.ReadAll(resp.Body)
    fmt.Println(string(body))
}

发送 JSON 的 POST 请求

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package main

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

func main() {
    client := &http.Client{}
    data := make(map[string]interface{})
    data["name"] = "patrick"
    data["age"] = "20"
    bytesData, _ := json.Marshal(data)
    req, _ := http.NewRequest("POST","https://blog.cnpatrickstar.com/post",bytes.NewReader(bytesData))
    resp, _ := client.Do(req)
    body, _ := ioutil.ReadAll(resp.Body)
    fmt.Println(string(body))
}

不用 client 的 POST 请求

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package main

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

func main() {
    data := make(map[string]interface{})
    data["name"] = "patrick"
    data["age"] = "20"
    bytesData, _ := json.Marshal(data)
    resp, _ := http.Post("https://blog.cnpatrickstar.com/post","application/json", bytes.NewReader(bytesData))
    body, _ := ioutil.ReadAll(resp.Body)
    fmt.Println(string(body))
}