Go——gin 框架基本入门

概述

• 为何不选择 beego，理由很简单，其设计风格已经不符合现在开发潮流，现实往往就是这样，看似完美实则鸡肋

• gin 最大的特点，也是我最为看重的就是中间件功能，说真的，当我在 gin 框架中看到 next 这个关键字，心里真的有点小激动

中间件

• 全局中间件

  import (
  	"log"
  	"net/http"
  	"github.com/gin-gonic/gin"
  )
  
  func logger() gin.HandlerFunc {
  
  	return func(c *gin.Context) {
  		log.Println("before is next")
  		c.Next()
  		log.Println("after is next ")
  	}
  }
  
  func main() {
  
  	r := gin.New()
  
  	r.Use(logger())
  
  	r.GET("/user/:name", func(c *gin.Context) {
  		name := c.Param("name")
  		c.String(http.StatusOK, "Hello %s", name)
  	})
  
  	r.GET("/topic/:id", func(c *gin.Context) {
  		id := c.Param("id")
  		c.String(http.StatusOK, "you search is %s", id)
  	})
  
  	r.Run(":8080")
  }
  

• 路由中间件

  func m1() gin.HandlerFunc {
  	return func(c *gin.Context) {
  
  		log.Println("before is m1")
  		c.Next()
  		log.Println("after is m1 ")
  	}
  }
  
  func m2() gin.HandlerFunc {
  	return func(c *gin.Context) {
  
  		log.Println("before is m2")
  		c.Next()
  		log.Println("after is m2 ")
  	}
  }
  
  func main() {
  
  	r := gin.New()
  
  	r.GET("/user/:name", m1(), func(c *gin.Context) {
  		name := c.Param("name")
  		c.String(http.StatusOK, "Hello %s", name)
  	})
  
  	r.GET("/topic/:id", m2(), func(c *gin.Context) {
  		id := c.Param("id")
  		c.String(http.StatusOK, "you search is %s", id)
  	})
  
  	r.Run(":8080")
  }
  

• 路由组中间件

  func main() {
  
  	r := gin.New()
  
  	v1 := r.Group("v1", m1())
  	v1.GET("/user/:name", func(c *gin.Context) {
  		name := c.Param("name")
  		c.String(http.StatusOK, "Hello %s", name)
  	})
  	v1.GET("/topic/:id", func(c *gin.Context) {
  		id := c.Param("id")
  		c.String(http.StatusOK, "you search is %s", id)
  	})
  
  	v2 := r.Group("v2", m2())
  	v2.GET("/user/:name", func(c *gin.Context) {
  		name := c.Param("name")
  		c.String(http.StatusOK, "Hello %s", name)
  	})
  	v2.GET("/topic/:id", func(c *gin.Context) {
  		id := c.Param("id")
  		c.String(http.StatusOK, "you search is %s", id)
  	})
  
  	r.Run(":8080")
  }
  

• 在中间件或处理程序中启动新的 Goroutines 时，您不应该使用其中的原始上下文，您必须使用只读副本

  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 serve on 0.0.0.0:8080
  	r.Run(":8080")
  }
  

帮助文档

• https://godoc.org/

• https://www.cnblogs.com/xielideboke/p/golang.html

• https://www.jianshu.com/p/a31e4ee25305