golang返回json等格式数据

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知我者谓我心忧，不知我者谓我何求，悠悠苍天，此何人哉

Sending Headers Only

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package main

import (
  "net/http"
)

func main() {
  http.HandleFunc("/", foo)
  http.ListenAndServe(":3000", nil)
}

func foo(w http.ResponseWriter, r *http.Request) {
  w.Header().Set("Server", "A Go Web Server")
  w.WriteHeader(200)
}

Rendering Plain Text

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package main

import (
  "net/http"
)

func main() {
  http.HandleFunc("/", foo)
  http.ListenAndServe(":3000", nil)
}

func foo(w http.ResponseWriter, r *http.Request) {
  w.Write([]byte("OK"))
}

Rendering JSON

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package main

import (
  "encoding/json"
  "net/http"
)

type Profile struct {
  Name    string
  Hobbies []string
}

func main() {
  http.HandleFunc("/", foo)
  http.ListenAndServe(":3000", nil)
}

func foo(w http.ResponseWriter, r *http.Request) {
  profile := Profile{"Alex", []string{"snowboarding", "programming"}}

  js, err := json.Marshal(profile)
  if err != nil {
    http.Error(w, err.Error(), http.StatusInternalServerError)
    return
  }

  w.Header().Set("Content-Type", "application/json")
  w.Write(js)
}

Rendering XML

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package main

import (
  "encoding/xml"
  "net/http"
)

type Profile struct {
  Name    string
  Hobbies []string `xml:"Hobbies>Hobby"`
}

func main() {
  http.HandleFunc("/", foo)
  http.ListenAndServe(":3000", nil)
}

func foo(w http.ResponseWriter, r *http.Request) {
  profile := Profile{"Alex", []string{"snowboarding", "programming"}}

  x, err := xml.MarshalIndent(profile, "", "  ")
  if err != nil {
    http.Error(w, err.Error(), http.StatusInternalServerError)
    return
  }

  w.Header().Set("Content-Type", "application/xml")
  w.Write(x)
}

Serving a File

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package main

import (
  "net/http"
  "path"
)

func main() {
  http.HandleFunc("/", foo)
  http.ListenAndServe(":3000", nil)
}

func foo(w http.ResponseWriter, r *http.Request) {
  // Assuming you want to serve a photo at 'images/foo.png'
  fp := path.Join("images", "foo.png")
  http.ServeFile(w, r, fp)
}

Important: http.ServeFile() does not automatically sanitize the file path. So if you’re constructing a file path from untrusted user input, you must sanitize the input with filepath.Clean() before using it to avoid directory traversal attacks.

Rendering a HTML Template

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File: templates/index.html

<h1>Hello {{ .Name }}</h1>
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit.</p>
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package main

import (
  "html/template"
  "net/http"
  "path"
)

type Profile struct {
  Name    string
  Hobbies []string
}

func main() {
  http.HandleFunc("/", foo)
  http.ListenAndServe(":3000", nil)
}

func foo(w http.ResponseWriter, r *http.Request) {
  profile := Profile{"Alex", []string{"snowboarding", "programming"}}

  fp := path.Join("templates", "index.html")
  tmpl, err := template.ParseFiles(fp)
  if err != nil {
    http.Error(w, err.Error(), http.StatusInternalServerError)
    return
  }

  if err := tmpl.Execute(w, profile); err != nil {
    http.Error(w, err.Error(), http.StatusInternalServerError)
  }
}

Rendering a HTML Template to a String

Instead of passing in the http.ResponseWriter when executing your template (like in the above snippet) use a buffer instead:

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...
buf := new(bytes.Buffer)
if err := tmpl.Execute(buf, profile); err != nil {
  http.Error(w, err.Error(), http.StatusInternalServerError)
}
templateString := buf.String()
...

Using Layouts and Nested Templates

File: templates/layout.html

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<html>
  <head>
    <title>{{ template "title" . }}</title>
  </head>
  <body>
    {{ template "content" . }}
  </body>
</html>

File: templates/index.html

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{{ define "title" }}An example layout{{ end }}

{{ define "content" }}
<h1>Hello {{ .Name }}</h1>
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit.</p>
{{ end }}

File: main.go

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package main

import (
  "html/template"
  "net/http"
  "path"
)

type Profile struct {
  Name    string
  Hobbies []string
}

func main() {
  http.HandleFunc("/", foo)
  http.ListenAndServe(":3000", nil)
}

func foo(w http.ResponseWriter, r *http.Request) {
  profile := Profile{"Alex", []string{"snowboarding", "programming"}}

  lp := path.Join("templates", "layout.html")
  fp := path.Join("templates", "index.html")

  // Note that the layout file must be the first parameter in ParseFiles
  tmpl, err := template.ParseFiles(lp, fp)
  if err != nil {
    http.Error(w, err.Error(), http.StatusInternalServerError)
    return
  }

  if err := tmpl.Execute(w, profile); err != nil {
    http.Error(w, err.Error(), http.StatusInternalServerError)
  }
}

https://www.alexedwards.net/blog/golang-response-snippets