diff --git a/src/main/java/com/example/springdemo/security/jwt/JwtAuthenticationFilter.java b/src/main/java/com/example/springdemo/security/jwt/JwtAuthenticationFilter.java
index 3d7f08b..2ae81de 100644
--- a/src/main/java/com/example/springdemo/security/jwt/JwtAuthenticationFilter.java
+++ b/src/main/java/com/example/springdemo/security/jwt/JwtAuthenticationFilter.java
@@ -6,7 +6,6 @@ import jakarta.servlet.ServletException;
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
 import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
 import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
 import org.springframework.security.core.context.SecurityContextHolder;
 import org.springframework.security.core.userdetails.UserDetails;
@@ -38,7 +37,7 @@ public class JwtAuthenticationFilter extends OncePerRequestFilter {
         if (StringUtils.hasText(token) && jwtTokenProvider.validateToken(token)) {
             // 从 token 获取 username
             String username = jwtTokenProvider.getUsername(token);
-            // 加载与令 token 关联的用户
+            // 加载与 token 关联的用户
             UserDetails userDetails = userDetailsService.loadUserByUsername(username);
             UsernamePasswordAuthenticationToken authenticationToken = new UsernamePasswordAuthenticationToken(
                     userDetails,
@@ -53,14 +52,14 @@ public class JwtAuthenticationFilter extends OncePerRequestFilter {
         filterChain.doFilter(request, response);
     }
 
-    private @Nullable String getTokenFromRequest(@NotNull HttpServletRequest request) {
+    private @NotNull String getTokenFromRequest(@NotNull HttpServletRequest request) {
 
         String bearerToken = request.getHeader("Authorization");
 
         if (StringUtils.hasText(bearerToken) && bearerToken.startsWith("Bearer ")) {
             return bearerToken.substring(7);
+        } else {
+            return "";
         }
-
-        return null;
     }
 }
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