获取Post参数
func main() {
        router := gin.Default()

        router.POST("/form_post", func(c *gin.Context) {
                message := c.PostForm("message")
                nick := c.DefaultPostForm("nick", "anonymous") // 此方法可以设置默认值

                c.JSON(200, gin.H{
                        "status":  "posted",
                        "message": message,
                        "nick":    nick,
                })
        })
        router.Run(":8080")
}