2.6 中间件和next函数

1. 无中间件启动

#使用
r := gin.New()
#替代
// 默认启动方式，包含 Logger、Recovery 中间件
r := gin.Default()

2. 使用中间件

func main() {
    // 创建一个不包含中间件的路由器
    r := gin.New()
    // 全局中间件
    // 使用 Logger 中间件
    r.Use(gin.Logger())
    // 使用 Recovery 中间件
    r.Use(gin.Recovery())
    // 路由添加中间件，可以添加任意多个
    r.GET("/benchmark", MyBenchLogger(), benchEndpoint)
    // 路由组中添加中间件
    // 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 serve on 0.0.0.0:8080
    r.Run(":8080")
}

3. 自定义组件

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