diff --git a/src/main/java/org/edgegallery/user/auth/controller/VerificationController.java b/src/main/java/org/edgegallery/user/auth/controller/VerificationController.java
index 657933762b65cbb8dec77a028831843b46b46e02..36d1f4b7bd9ba007581c62c7c79f967e7ffe6d38 100644
--- a/src/main/java/org/edgegallery/user/auth/controller/VerificationController.java
+++ b/src/main/java/org/edgegallery/user/auth/controller/VerificationController.java
@@ -109,8 +109,7 @@ public class VerificationController extends BeGenericServlet {
     @GetMapping(value = "/verifycode-image/precheck", produces = MediaType.APPLICATION_JSON_VALUE)
     @ResponseBody
     @ApiOperation(value = "check image verification code", response = Object.class)
-    public ResponseEntity<Object> preCheckImgVerificationCode(HttpServletRequest httpServletRequest)
-        throws IOException {
+    public ResponseEntity<Object> preCheckImgVerificationCode(HttpServletRequest httpServletRequest) {
         return buildResponse(identityService.preCheckImgVerificationCode(httpServletRequest));
     }
 }
diff --git a/src/main/java/org/edgegallery/user/auth/controller/dto/request/TenantRegisterReqDto.java b/src/main/java/org/edgegallery/user/auth/controller/dto/request/TenantRegisterReqDto.java
index 98023402568b85e1c78cf19c885705099e9a756a..4616171aa62da8c6f641c139f25438adbfc4740b 100644
--- a/src/main/java/org/edgegallery/user/auth/controller/dto/request/TenantRegisterReqDto.java
+++ b/src/main/java/org/edgegallery/user/auth/controller/dto/request/TenantRegisterReqDto.java
@@ -16,8 +16,6 @@
 
 package org.edgegallery.user.auth.controller.dto.request;
 
-import com.fasterxml.jackson.annotation.JsonProperty;
-import com.google.gson.annotations.SerializedName;
 import io.swagger.annotations.ApiModel;
 import io.swagger.annotations.ApiModelProperty;
 import javax.validation.constraints.Pattern;
diff --git a/src/main/java/org/edgegallery/user/auth/utils/Consts.java b/src/main/java/org/edgegallery/user/auth/utils/Consts.java
index 40d072606e8cc933887ea0957ba30dbe9862cb94..01b8a6df7af6b4ae3b7449a7f1a5f9ca1a5279fc 100644
--- a/src/main/java/org/edgegallery/user/auth/utils/Consts.java
+++ b/src/main/java/org/edgegallery/user/auth/utils/Consts.java
@@ -38,6 +38,9 @@ public class Consts {
     public static final long MILLIS_ONE_DAY = 1 * 24 * 3600 * 1000L;
 
     public static final class PwModifyScene {
+        private PwModifyScene() {
+        }
+
         public static final int FIRSTLOGIN = 1;
 
         public static final int EXPIRED = 2;