diff --git a/src/main/java/co/jp/app/service/JwtService.java b/src/main/java/co/jp/app/service/JwtService.java
index ff0cd74..60ff64f 100644
--- a/src/main/java/co/jp/app/service/JwtService.java
+++ b/src/main/java/co/jp/app/service/JwtService.java
@@ -2,6 +2,7 @@ package co.jp.app.service;
 
 import io.jsonwebtoken.*;
 import io.jsonwebtoken.security.Keys;
+import io.jsonwebtoken.security.SignatureException;
 import java.util.function.Function;
 
 import org.slf4j.Logger;
@@ -83,10 +84,11 @@ public class JwtService {
 
             return (username.equals(userDetails.getUsername()) && !isTokenActuallyExpired(token));
         } catch (ExpiredJwtException e) {
+
             logger.warn("Token validation failed: Expired JWT - {}", e.getMessage());
             return false;
         } catch (MalformedJwtException | SignatureException | UnsupportedJwtException | IllegalArgumentException e) {
-            // 这些是更严重的token结构或签名问题
+
             logger.error("Token validation failed: Invalid JWT (format, signature, etc.) - {}", e.getMessage());
             return false;
         }