安装

快速入门

package main

import (
	"net/http"

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

func pong(c *gin.Context) {
	c.JSON(http.StatusOK, gin.H{
		"message": "pong",
	})
}
func main() {
	// 实例化一个gin的server对象
  // Creates a gin router with default middleware:
	// logger and recovery (crash-free) middleware
	r := gin.Default()
	// 定义一个接口
	r.GET("/ping", pong)
	// 监听8083端口
	r.Run(":8083") 
}

代码很简单，这样就启动了服务

使用get、post、put等方法

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
}

url和路由分组

路由分组：每一个服务下面都有很多的接口，所以需要给每个服务建立一个分组。

package main

import (
	"net/http"

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

func main() {
	router := gin.Default()
	goodsGroup := router.Group("/goods")
	{
		goodsGroup.GET("", goodsList)
		goodsGroup.GET("/:id/:action/add", goodsDetail) //获取商品id为1的详细信息 模式
		goodsGroup.POST("", createGoods)
	}

	router.Run(":8083")
}

func createGoods(c *gin.Context) {

}

func goodsDetail(c *gin.Context) {
  // 获取参数
	id := c.Param("id")
	action := c.Param("action")
	c.JSON(http.StatusOK, gin.H{
		"id":     id,
		"action": action,
	})
}

func goodsList(context *gin.Context) {
	context.JSON(http.StatusOK, gin.H{
		"name": "goodsList",
	})
}

获取url参数


func main() {
	router := gin.Default()

	// 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 [...]")
	})

	router.Run(":8080")
}

从get和post 方法中获取参数

package main

import (
	"net/http"

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

func main() {
	router := gin.Default()

	router.GET("/welcome", welcome)
	router.POST("/form_post", formPost)
	router.POST("/post", getPost)

	router.Run(":8083")
}

func getPost(c *gin.Context) {
	id := c.Query("id")
	page := c.DefaultQuery("page", "0")
	name := c.PostForm("name")
	message := c.DefaultPostForm("message", "信息")
	c.JSON(http.StatusOK, gin.H{
		"id":      id,
		"page":    page,
		"name":    name,
		"message": message,
	})
}

func formPost(c *gin.Context) {
	message := c.PostForm("message")
	nick := c.DefaultPostForm("nick", "anonymous")
	c.JSON(http.StatusOK, gin.H{
		"message": message,
		"nick":    nick,
	})
}

func welcome(c *gin.Context) {
	firstName := c.DefaultQuery("firstname", "bobby")
	lastName := c.DefaultQuery("lastname", "imooc")
	c.JSON(http.StatusOK, gin.H{
		"first_name": firstName,
		"last_name":  lastName,
	})
}

自定义gin中间件

什么是中间件

这个和koa还有egg的中间件类似

实现一个打log的中间件

func MyLogger() gin.HandlerFunc {
	// 返回一个函数就可以了
	return func(c *gin.Context) {
		t := time.Now()
		c.Set("example", "123456")
		// 让原本应该执行的逻辑继续执行
		c.Next()
		// 执行完以后，然后再执行之类的逻辑
		end := time.Since(t)
		fmt.Printf("耗时:%v\n", end)
		status := c.Writer.Status()
		fmt.Println("状态", status)
	}
}

gin 中间件原理

使用切片，如果调用了next，就会调用切片的下一个函数，这里使用了一个index索引

gin 退出

package main

import (
	"context"
	"errors"
	"log"
	"net/http"
	"os"
	"os/signal"
	"syscall"
	"time"

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

func main() {
	router := gin.Default()
	router.GET("/", func(c *gin.Context) {
		time.Sleep(5 * time.Second)
		c.String(http.StatusOK, "Welcome Gin Server")
	})

	srv := &http.Server{
		Addr:    ":8080",
		Handler: router,
	}

	// Initializing the server in a goroutine so that
	// it won't block the graceful shutdown handling below
	// 在协程中使用，
	go func() {
		if err := srv.ListenAndServe(); err != nil && errors.Is(err, http.ErrServerClosed) {
			log.Printf("listen: %s\n", err)
		}
	}()

	// Wait for interrupt signal to gracefully shutdown the server with
	// a timeout of 5 seconds.
	quit := make(chan os.Signal, 2)
	// kill (no param) default send syscall.SIGTERM
	// kill -2 is syscall.SIGINT
	// kill -9 is syscall.SIGKILL but can't be caught, so don't need to add it
	// 准备接受信号
	signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)
	<-quit
	log.Println("Shutting down server...")
	
	// The context is used to inform the server it has 5 seconds to finish
	// the request it is currently handling
	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()

	if err := srv.Shutdown(ctx); err != nil {
		log.Fatal("Server forced to shutdown:", err)
	}

	log.Println("Server exiting")
}

Gin 入门

安装