修复格式问题，重构嵌套层数过深的函数

server/middleware/jwt.go

@@ -60,10 +60,10 @@ type JWT struct {
 }
 
 var (
-	TokenExpired     error = errors.New("Token is expired")
-	TokenNotValidYet error = errors.New("Token not active yet")
-	TokenMalformed   error = errors.New("That's not even a token")
-	TokenInvalid     error = errors.New("Couldn't handle this token:")
+	TokenExpired     = errors.New("Token is expired")
+	TokenNotValidYet = errors.New("Token not active yet")
+	TokenMalformed   = errors.New("That's not even a token")
+	TokenInvalid     = errors.New("Couldn't handle this token:")
 )
 
 func NewJWT() *JWT {
@@ -72,13 +72,13 @@ func NewJWT() *JWT {
 	}
 }
 
-//创建一个token
+// 创建一个token
 func (j *JWT) CreateToken(claims request.CustomClaims) (string, error) {
 	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
 	return token.SignedString(j.SigningKey)
 }
 
-//解析 token
+// 解析 token
 func (j *JWT) ParseToken(tokenString string) (*request.CustomClaims, error) {
 	token, err := jwt.ParseWithClaims(tokenString, &request.CustomClaims{}, func(token *jwt.Token) (i interface{}, e error) {
 		return j.SigningKey, nil