Gin框架使用（1）｜青训营笔记

• 安装

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

• 在项目代码中导入

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

• 第一个例子：发送get请求

func main() {
    r := gin.Default() 
    r.GET("/ping", func(c *gin.Context) {
            c.JSON(http.StatusOK, gin.H{
                    "message": "pong",
            })
    })
    r.Run() // listen and serve on 0.0.0.0:8080 (for windows "localhost:8080")
}

gin.Default() 函数会生成一个默认的 Engine 对象，里面包含了 2 个默认的常用插件，分别是 Logger 和 Recovery，Logger 用于输出请求日志，Recovery 确保单个请求发生 panic 时记录异常堆栈日志，输出统一的错误响应。

r.GET向路由/ping发送一个GET请求,执行匿名函数，函数功能是返回一个JSON。

r.Run()启动gin服务，默认端口8080。

• 更多请求类型

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
}

• 请求参数

// This handler will match /user/john but will not match /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)
})

// For each matched request Context will hold the route definition
router.POST("/user/:name/*action", func(c *gin.Context) {
        b := c.FullPath() == "/user/:name/*action" // true
        c.String(http.StatusOK, "%t", b)
})

// This handler will add a new router for /user/groups.
// Exact routes are resolved before param routes, regardless of the order they were defined.
// Routes starting with /user/groups are never interpreted as /user/:name/... routes
router.GET("/user/groups", func(c *gin.Context) {
        c.String(http.StatusOK, "The available groups are [...]")
})

• 获取参数

// 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)
})

• 表单参数

router.POST("/form_post", func(c *gin.Context) {
        message := c.PostForm("message")
        nick := c.DefaultPostForm("nick", "anonymous")

        c.JSON(http.StatusOK, gin.H{
                "status":  "posted",
                "message": message,
                "nick":    nick,
        })
})