翻译自: https://github.com/gin-gonic/gin/blob/develop/README.md

Gin Web框架

Gin是用Golang实现的一种Web框架。基于 httprouter，它提供了相似martini但更好性能(路由性能约快40倍)的API服务. 假设你希望构建一个高性能的生产环境，你会喜欢上使用 Gin。

$ cat test.go

package mainimport "github.com/gin-gonic/gin"func main() {r := gin.Default()r.GET("/ping", func(c *gin.Context) {c.JSON(200, gin.H{"message": "pong",})})r.Run() // listen and server on 0.0.0.0:8080
}

基准測试

Gin基于HttpRouter的这个定制版本号来构建。

查看所有測试

(1): 总反复次数
(2): 单次请求耗时 (ns/op)
(3): 堆内存大小 (B/op)
(4): 单次请求内存分配数 (allocs/op)

Gin v1. stable

• [x] 零分配路由.
• [x] 从路由到写请求, 依旧为最快的路由器和框架.
• [x] 完备的单元測试套件.
• [x] Battle tested.(?

  )

• [x] API冻结, 新的release版不会影响现有的代码.

高速開始

1. 下载并安装Gin:

   $ go get github.com/gin-gonic/gin

2. 在代码中import进来:

   import "github.com/gin-gonic/gin"

3. (可选) Import net/http. 假设用到诸如 http.StatusOK的常量, 须要引入该包:

   import "net/http"

API演示样例

使用 GET, POST, PUT, PATCH, DELETE 以及 OPTIONS

func main() {// Creates a gin router with default middleware:// logger and recovery (crash-free) middlewarerouter := gin.Default()router.GET("/someGet", getting)router.POST("/somePost", posting)router.PUT("/somePut", putting)router.DELETE("/someDelete", deleting)router.PATCH("/somePatch", patching)router.HEAD("/someHead", head)router.OPTIONS("/someOptions", options)// By default it serves on :8080 unless a// PORT environment variable was defined.router.Run()// router.Run(":3000") for a hard coded port
}

路径參数

func main() {router := gin.Default()// This handler will match /user/john but will not match neither /user/ or /userrouter.GET("/user/:name", func(c *gin.Context) {name := c.Param("name")c.String(http.StatusOK, "Hello %s", name)})// However, this one will match /user/john/ and also /user/john/send// If no other routers match /user/john, it will redirect to /user/john/router.GET("/user/:name/*action", func(c *gin.Context) {name := c.Param("name")action := c.Param("action")message := name + " is " + actionc.String(http.StatusOK, message)})router.Run(":8080")
}

查询字符串參数

func main() {router := gin.Default()// Query string parameters are parsed using the existing underlying request object.// The request responds to a url matching:  /welcome?firstname=Jane&lastname=Doerouter.GET("/welcome", func(c *gin.Context) {firstname := c.DefaultQuery("firstname", "Guest")lastname := c.Query("lastname") // shortcut for c.Request.URL.Query().Get("lastname")c.String(http.StatusOK, "Hello %s %s", firstname, lastname)})router.Run(":8080")
}

Multipart/Urlencoded表单提交

func main() {router := gin.Default()router.POST("/form_post", func(c *gin.Context) {message := c.PostForm("message")nick := c.DefaultPostForm("nick", "anonymous")c.JSON(200, gin.H{"status":  "posted","message": message,"nick":    nick,})})router.Run(":8080")
}

很多其它演示样例: 查询參数 + POST表单提交

POST /post?id=1234&page=1 HTTP/1.1
Content-Type: application/x-www-form-urlencodedname=manu&message=this_is_great

func main() {router := gin.Default()router.POST("/post", func(c *gin.Context) {id := c.Query("id")page := c.DefaultQuery("page", "0")name := c.PostForm("name")message := c.PostForm("message")fmt.Printf("id: %s; page: %s; name: %s; message: %s", id, page, name, message)})router.Run(":8080")
}

id: 1234; page: 1; name: manu; message: this_is_great

很多其它演示样例: 上传文件

參考问题 #548.

func main() {router := gin.Default()router.POST("/upload", func(c *gin.Context) {file, header , err := c.Request.FormFile("upload")filename := header.Filenamefmt.Println(header.Filename)out, err := os.Create("./tmp/"+filename+".png")if err != nil {log.Fatal(err)}defer out.Close()_, err = io.Copy(out, file)if err != nil {log.Fatal(err)}})router.Run(":8080")
}

分组路由

func main() {router := gin.Default()// Simple group: v1v1 := router.Group("/v1"){v1.POST("/login", loginEndpoint)v1.POST("/submit", submitEndpoint)v1.POST("/read", readEndpoint)}// Simple group: v2v2 := router.Group("/v2"){v2.POST("/login", loginEndpoint)v2.POST("/submit", submitEndpoint)v2.POST("/read", readEndpoint)}router.Run(":8080")
}

不使用中间件, 使用Gin默认配置

使用

r := gin.New()

来取代

r := gin.Default()

使用中间件

func main() {// Creates a router without any middleware by defaultr := gin.New()// Global middlewarer.Use(gin.Logger())r.Use(gin.Recovery())// Per route middleware, you can add as many as you desire.r.GET("/benchmark", MyBenchLogger(), benchEndpoint)// Authorization group// authorized := r.Group("/", AuthRequired())// exactly the same as:authorized := r.Group("/")// per group middleware! in this case we use the custom created// AuthRequired() middleware just in the "authorized" group.authorized.Use(AuthRequired()){authorized.POST("/login", loginEndpoint)authorized.POST("/submit", submitEndpoint)authorized.POST("/read", readEndpoint)// nested grouptesting := authorized.Group("testing")testing.GET("/analytics", analyticsEndpoint)}// Listen and server on 0.0.0.0:8080r.Run(":8080")
}

model binding与验证

要绑定一个请求body到某个类型, 能够使用model binding。 眼下支持JSON, XML 以及标准from格式 (foo=bar&boo=baz)的绑定。

所有你想要绑定的域(field)。 须要你设置相应的绑定标识。 比如, 要绑定到JSON, 则这样声明json:"fieldname"。

使用Bind方法时, Gin会尝试通过Content-Type头部来推定绑定的类型(如json还是form)。而假设你明白知道要绑定的类型, 能够使用BindWith方法。

你也能够指定哪些filed须要绑定。 假设某个filed像这样声明: binding:"required", 那么在进行绑定时假设发现是空值(注: 是请求中不存在该field名?), 当前的请求会失败并收到错误提示。

// Binding from JSON
type Login struct {User     string `form:"user" json:"user" binding:"required"`Password string `form:"password" json:"password" binding:"required"`
}func main() {router := gin.Default()// Example for binding JSON ({"user": "manu", "password": "123"})router.POST("/loginJSON", func(c *gin.Context) {var json Loginif c.BindJSON(&json) == nil {if json.User == "manu" && json.Password == "123" {c.JSON(http.StatusOK, gin.H{"status": "you are logged in"})} else {c.JSON(http.StatusUnauthorized, gin.H{"status": "unauthorized"})}}})// Example for binding a HTML form (user=manu&password=123)router.POST("/loginForm", func(c *gin.Context) {var form Login// This will infer what binder to use depending on the content-type header.if c.Bind(&form) == nil {if form.User == "manu" && form.Password == "123" {c.JSON(http.StatusOK, gin.H{"status": "you are logged in"})} else {c.JSON(http.StatusUnauthorized, gin.H{"status": "unauthorized"})}}})// Listen and server on 0.0.0.0:8080router.Run(":8080")
}

Multipart/Urlencoded表单请求方式的绑定

package mainimport ("github.com/gin-gonic/gin""github.com/gin-gonic/gin/binding"
)type LoginForm struct {User     string `form:"user" binding:"required"`Password string `form:"password" binding:"required"`
}func main() {router := gin.Default()router.POST("/login", func(c *gin.Context) {// you can bind multipart form with explicit binding declaration:// c.BindWith(&form, binding.Form)// or you can simply use autobinding with Bind method:var form LoginForm// in this case proper binding will be automatically selectedif c.Bind(&form) == nil {if form.User == "user" && form.Password == "password" {c.JSON(200, gin.H{"status": "you are logged in"})} else {c.JSON(401, gin.H{"status": "unauthorized"})}}})router.Run(":8080")
}

使用下面命令測试:

$ curl -v --form user=user --form password=password http://localhost:8080/login

XML和JSON的渲染

func main() {r := gin.Default()// gin.H is a shortcut for map[string]interface{}r.GET("/someJSON", func(c *gin.Context) {c.JSON(http.StatusOK, gin.H{"message": "hey", "status": http.StatusOK})})r.GET("/moreJSON", func(c *gin.Context) {// You also can use a structvar msg struct {Name    string `json:"user"`Message stringNumber  int}msg.Name = "Lena"msg.Message = "hey"msg.Number = 123// Note that msg.Name becomes "user" in the JSON// Will output  :   {"user": "Lena", "Message": "hey", "Number": 123}c.JSON(http.StatusOK, msg)})r.GET("/someXML", func(c *gin.Context) {c.XML(http.StatusOK, gin.H{"message": "hey", "status": http.StatusOK})})// Listen and server on 0.0.0.0:8080r.Run(":8080")
}

处理静态文件的请求

func main() {router := gin.Default()router.Static("/assets", "./assets")router.StaticFS("/more_static", http.Dir("my_file_system"))router.StaticFile("/favicon.ico", "./resources/favicon.ico")// Listen and server on 0.0.0.0:8080router.Run(":8080")
}

HTML模板渲染

Using LoadHTMLTemplates()

func main() {router := gin.Default()router.LoadHTMLGlob("templates/*")//router.LoadHTMLFiles("templates/template1.html", "templates/template2.html")router.GET("/index", func(c *gin.Context) {c.HTML(http.StatusOK, "index.tmpl", gin.H{"title": "Main website",})})router.Run(":8080")
}

templates/index.tmpl

<html><h1>{{ .title }}</h1>
</html>

使用不同路径下但同样文件名称的模板

func main() {router := gin.Default()router.LoadHTMLGlob("templates/**/*")router.GET("/posts/index", func(c *gin.Context) {c.HTML(http.StatusOK, "posts/index.tmpl", gin.H{"title": "Posts",})})router.GET("/users/index", func(c *gin.Context) {c.HTML(http.StatusOK, "users/index.tmpl", gin.H{"title": "Users",})})router.Run(":8080")
}

templates/posts/index.tmpl

{{ define "posts/index.tmpl" }}
<html><h1>{{ .title }}
</h1>
<p>Using posts/index.tmpl</p>
</html>
{{ end }}

templates/users/index.tmpl

{{ define "users/index.tmpl" }}
<html><h1>{{ .title }}
</h1>
<p>Using users/index.tmpl</p>
</html>
{{ end }}

你也能够使用自己的渲染模板

import "html/template"func main() {router := gin.Default()html := template.Must(template.ParseFiles("file1", "file2"))router.SetHTMLTemplate(html)router.Run(":8080")
}

重定向

实现HTTP重定向并不麻烦:

r.GET("/test", func(c *gin.Context) {c.Redirect(http.StatusMovedPermanently, "http://www.google.com/")
})

内部或外部的地址都是支持的。

定制中间件

func Logger() gin.HandlerFunc {return func(c *gin.Context) {t := time.Now()// Set example variablec.Set("example", "12345")// before requestc.Next()// after requestlatency := time.Since(t)log.Print(latency)// access the status we are sendingstatus := c.Writer.Status()log.Println(status)}
}func main() {r := gin.New()r.Use(Logger())r.GET("/test", func(c *gin.Context) {example := c.MustGet("example").(string)// it would print: "12345"log.Println(example)})// Listen and server on 0.0.0.0:8080r.Run(":8080")
}

使用 BasicAuth() 中间件

// simulate some private data
var secrets = gin.H{"foo":    gin.H{"email": "foo@bar.com", "phone": "123433"},"austin": gin.H{"email": "austin@example.com", "phone": "666"},"lena":   gin.H{"email": "lena@guapa.com", "phone": "523443"},
}func main() {r := gin.Default()// Group using gin.BasicAuth() middleware// gin.Accounts is a shortcut for map[string]stringauthorized := r.Group("/admin", gin.BasicAuth(gin.Accounts{"foo":    "bar","austin": "1234","lena":   "hello2","manu":   "4321",}))// /admin/secrets endpoint// hit "localhost:8080/admin/secretsauthorized.GET("/secrets", func(c *gin.Context) {// get user, it was set by the BasicAuth middlewareuser := c.MustGet(gin.AuthUserKey).(string)if secret, ok := secrets[user]; ok {c.JSON(http.StatusOK, gin.H{"user": user, "secret": secret})} else {c.JSON(http.StatusOK, gin.H{"user": user, "secret": "NO SECRET :("})}})// Listen and server on 0.0.0.0:8080r.Run(":8080")
}

中间件中的Goroutines

在一个middleware或handler中使用goroutine时, 你不能直接使用源gin.Context, 而仅仅能使用它的一份仅仅读拷贝。

func main() {r := gin.Default()r.GET("/long_async", func(c *gin.Context) {// create copy to be used inside the goroutinecCp := c.Copy()go func() {// simulate a long task with time.Sleep(). 5 secondstime.Sleep(5 * time.Second)// note that you are using the copied context "cCp", IMPORTANTlog.Println("Done! in path " + cCp.Request.URL.Path)}()})r.GET("/long_sync", func(c *gin.Context) {// simulate a long task with time.Sleep(). 5 secondstime.Sleep(5 * time.Second)// since we are NOT using a goroutine, we do not have to copy the contextlog.Println("Done! in path " + c.Request.URL.Path)})// Listen and server on 0.0.0.0:8080r.Run(":8080")
}

自己定义HTTP配置

直接使用http.ListenAndServe()。 演示样例:

func main() {router := gin.Default()http.ListenAndServe(":8080", router)
}

或者

func main() {router := gin.Default()s := &http.Server{Addr:           ":8080",Handler:        router,ReadTimeout:    10 * time.Second,WriteTimeout:   10 * time.Second,MaxHeaderBytes: 1 << 20,}s.ListenAndServe()
}

平滑重新启动或关闭

是否须要平滑重新启动或关闭你的服务?有下面这些方式能够实现。

我们能够用 fvbock/endless来替换默认的方法 ListenAndServe，详情请參考#296。

router := gin.Default()
router.GET("/", handler)
// [...]
endless.ListenAndServe(":4242", router)

或者, 除使用endless之外的方法:

• manners: 一种平滑关闭自己的Go HTTP服务。