请求令牌时获取nil而不是* jwt.Token

Question

I'm trying to a the token to verify the user role but I get an error:

interface conversion: interface {} is nil, not *jwt.Token

I did something similar requesting the user ID and it worked but here I can't seem to get the token.

Code:

func AdminRoutes(next echo.HandlerFunc) echo.HandlerFunc {
    return func(c echo.Context) error {
        u := c.Get("user").(*jwt.Token)
        claims := u.Claims.(jwt.MapClaims)
        for _, item := range routes[claims["role"].(string)] {
            if c.Request().RequestURI == item && claims["role"] != "admin" {
                return c.JSON(http.StatusUnauthorized, "Role not suitable for function.")
            }
        }
        return next(c)
    }
}

I've tried to c.Set() the token but c.Get() doesn't work after.

Answer 1

The c.Get("user") returns nil value, and what you did was performing type assertion on nil value, it's the reason why the error occurs.

I suggest to put some checking on c.Get() before asserting it.

if temp := c.Get("user"); temp != nil {
    u := temp.(*jwt.Token)
    claims := u.Claims.(jwt.MapClaims)
    for _, item := range routes[claims["role"].(string)] {
        if c.Request().RequestURI == item && claims["role"] != "admin" {
            return c.JSON(http.StatusUnauthorized, "Role not suitable for function.")
        }
    }
}