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

Gin Web框架

Gin Web框架简单介绍-LMLPHP

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。

Gin Web框架简单介绍-LMLPHP

$ cat test.go

package main

import "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

BenchmarkAce_GithubAll	10000	109482	13792	167
BenchmarkBear_GithubAll	10000	287490	79952	943
BenchmarkBeego_GithubAll	3000	562184	146272	2092
BenchmarkBone_GithubAll	500	2578716	648016	8119
BenchmarkDenco_GithubAll	20000	94955	20224	167
BenchmarkEcho_GithubAll	30000	58705	0	0
BenchmarkGin_GithubAll	30000	50991	0	0
BenchmarkGocraftWeb_GithubAll	5000	449648	133280	1889
BenchmarkGoji_GithubAll	2000	689748	56113	334
BenchmarkGoJsonRest_GithubAll	5000	537769	135995	2940
BenchmarkGoRestful_GithubAll	100	18410628	797236	7725
BenchmarkGorillaMux_GithubAll	200	8036360	153137	1791
BenchmarkHttpRouter_GithubAll	20000	63506	13792	167
BenchmarkHttpTreeMux_GithubAll	10000	165927	56112	334
BenchmarkKocha_GithubAll	10000	171362	23304	843
BenchmarkMacaron_GithubAll	2000	817008	224960	2315
BenchmarkMartini_GithubAll	100	12609209	237952	2686
BenchmarkPat_GithubAll	300	4830398	1504101	32222
BenchmarkPossum_GithubAll	10000	301716	97440	812
BenchmarkR2router_GithubAll	10000	270691	77328	1182
BenchmarkRevel_GithubAll	1000	1491919	345553	5918
BenchmarkRivet_GithubAll	10000	283860	84272	1079
BenchmarkTango_GithubAll	5000	473821	87078	2470
BenchmarkTigerTonic_GithubAll	2000	1120131	241088	6052
BenchmarkTraffic_GithubAll	200	8708979	2664762	22390
BenchmarkVulcan_GithubAll	5000	353392	19894	609
BenchmarkZeus_GithubAll	2000	944234	300688	2648

(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

下载并安装Gin:
```
$ go get github.com/gin-gonic/gin
```
在代码中import进来:
```
import "github.com/gin-gonic/gin"
```
(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) middleware

    router := 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 /user

    router.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 " + action

        c.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=Doe

    router.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-urlencoded

name=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.Filename

            fmt.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: v1

    v1 := router.Group("/v1")

    {

        v1.POST("/login", loginEndpoint)

        v1.POST("/submit", submitEndpoint)

        v1.POST("/read", readEndpoint)

    }

    // Simple group: v2

    v2 := 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 default

    r := gin.New()

    // Global middleware

    r.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 group

        testing := authorized.Group("testing")

        testing.GET("/analytics", analyticsEndpoint)

    }

    // Listen and server on 0.0.0.0:8080

    r.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 Login

        if 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 0.0.0.0:8080

    router.Run(":8080")

}

Multipart/Urlencoded表单请求方式的绑定

package main

import (

    "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 selected

        if 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 struct

        var msg struct {

            Name    string `json:"user"`

            Message string

            Number  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 0.0.0.0:8080

    r.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 0.0.0.0:8080

    router.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 variable

        c.Set("example", "12345")

        // before request

        c.Next()

        // after request

        latency := time.Since(t)

        log.Print(latency)

        // access the status we are sending

        status := 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 0.0.0.0:8080

    r.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]string

    authorized := r.Group("/admin", gin.BasicAuth(gin.Accounts{

        "foo":    "bar",

        "austin": "1234",

        "lena":   "hello2",

        "manu":   "4321",

    }))

    // /admin/secrets endpoint

    // hit "localhost:8080/admin/secrets

    authorized.GET("/secrets", func(c *gin.Context) {

        // get user, it was set by the BasicAuth middleware

        user := 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 0.0.0.0:8080

    r.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 goroutine

        cCp := c.Copy()

        go func() {

            // simulate a long task with time.Sleep(). 5 seconds

            time.Sleep(5 * time.Second)

            // note that you are using the copied context "cCp", IMPORTANT

            log.Println("Done! in path " + cCp.Request.URL.Path)

        }()

    })

    r.GET("/long_sync", func(c *gin.Context) {

        // simulate a long task with time.Sleep(). 5 seconds

        time.Sleep(5 * time.Second)

        // since we are NOT using a goroutine, we do not have to copy the context

        log.Println("Done! in path " + c.Request.URL.Path)

    })

    // Listen and server on 0.0.0.0:8080

    r.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。