golang panic recover自定义异常处理

• panic

panic 这个词，在英语中具有恐慌、恐慌的等意思；panic 关键字主要用于主动抛出异常，类似 Python中的raise关键字

• recover

recover 这个词，在英语中具有恢复、复原等意思；从字面意思理解的话，在 Go 语言中，代表将程序状态从严重的错误中恢复到正常状态。Go语言中 recover 关键字主要用于捕获异常，让程序回到正常状态,类似Python中的except，用来捕获异常，可以在具体异常处理中做特殊操作。

• Custom Recovery behavior 自定义异常捕获行为

func main() {
	// Creates a router without any middleware by default
	r := gin.New()

	// Global middleware
	// Logger middleware will write the logs to gin.DefaultWriter even if you set with GIN_MODE=release.
	// By default gin.DefaultWriter = os.Stdout
	r.Use(gin.Logger())

	// Recovery middleware recovers from any panics and writes a 500 if there was one.
	r.Use(gin.CustomRecovery(func(c *gin.Context, recovered interface{}) {
		if err, ok := recovered.(string); ok {
			c.String(http.StatusInternalServerError, fmt.Sprintf("error: %s", err))
		}
		c.AbortWithStatus(http.StatusInternalServerError)
	}))

	r.GET("/panic", func(c *gin.Context) {
		// panic with a string -- the custom middleware could save this to a database or report it to the user
		panic("foo")
	})

	r.GET("/", func(c *gin.Context) {
		c.String(http.StatusOK, "ohai")
	})

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